Category: Precision Oncology

FDA Approves ALECENSA® as Adjuvant Treatment for ALK-Positive Non Small Cell Lung Cancer

RR

SUMMARY: The FDA on April 18, 2024, approved ALECENSA® (Alectinib) for adjuvant treatment following tumor resection in patients with Anaplastic Lymphoma Kinase (ALK)-positive Non Small Cell Lung Cancer (NSCLC), as detected by an FDA-approved test. Lung cancer is the second most common cancer in both men and women and accounts for about 12% of all new cancers and 21% of all cancer deaths. The American Cancer Society estimates that for 2024 about 234,580 new cases of lung cancer will be diagnosed and about 125,070 patients will die of the disease. Non Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of Non Small Cell Lung Cancer (NSCLC), 25% are Squamous cell carcinomas, 40% are Adenocarcinomas and 10% are Large cell carcinomas.

The discovery of rearrangements of the Anaplastic Lymphoma Kinase (ALK) gene in some patients with advanced NSCLC and adenocarcinoma histology, led to the development of agents such as XALKORI® (Crizotinib), ZYKADIA® (Ceritinib), ALECENSA® (Alectinib), ALUNBRIG® (Brigatinib) and LORBRENA® (Lorlatinib), with promising results. It has become clear that appropriate molecularly targeted therapy for tumors with a molecular abnormality, results in the best outcomes. According to the US Lung Cancer Mutation Consortium (LCMC), two thirds of patients with advanced adenocarcinoma of the lung, have a molecular driver abnormality. The most common oncogenic drivers in patients with advanced adenocarcinoma of the lung are, KRAS in 25%, EGFR in 21% and ALK in 5%, as well as other mutations in BRAF, HER2, AKT1, fusions involving RET and ROS oncogenes and MET gene alterations. These mutations are mutually exclusive and the presence of two simultaneous mutations, are rare.

Patients with ALK-positive NSCLC tend be younger nonsmokers and present with more advanced disease. Approximately 50-60% of these patients develop brain metastases. These patients are often treated with ALK TKIs that cross the blood brain barrier. Patients with early stage resected ALK-positive NSCLC receive adjuvant treatment with platinum-based combination chemotherapy, with 5-year survival ranging from 70% for Stage IB disease to about 35% for Stage IIIA disease, with associated chemotherapy related toxicities.

Alectinib is a potent, second-generation ALK Tyrosine Kinase Inhibitor, and is effective against several ALK mutations that confer resistance to Crizotinib. In the Phase III, randomized ALEX trial, treatment naïve patients with advanced ALK-positive NSCLC who received Alectinib had significantly longer Progression Free Survival and 5-year Overall Survival, compared to those who received Crizotinib, with substantial CNS activity.

The ADAURA trial investigated adjuvant TAGRISSO® (Osimertinib), a third-generation EGFR TKI, in patients with resected EGFR-mutated NSCLC of stage IB, II, or IIIA. Results showed benefits in Disease-Free and Overall Survival, along with reduced CNS recurrence. The ALINA trial similarly assessed the efficacy of Alectinib, in resected ALK-rearranged NSCLC.

ALINA is a global, open-label, randomized, Phase III trial, conducted to investigate the efficacy and safety of adjuvant Alectinib as compared with standard chemotherapy in patients with resected ALK-positive NSCLC. In this study, 257 eligible enrolled patients (N=257) were randomly assigned 4-12 weeks after patients had undergone complete surgical resection (lobectomy, sleeve lobectomy, bilobectomy, or pneumonectomy) in a 1:1 ratio to receive Alectinib 600 mg orally twice daily or platinum-based chemotherapy IV every 21 days for 4 cycles. Alectinib was given for 24 months. Chemotherapy consisted of Cisplatin 75 mg/m2 IV on day 1 of each cycle, plus Vinorelbine 25 mg/m2 IV on days 1 and 8, Gemcitabine 1250 mg/m2 IV on days 1 and 8, or Pemetrexed 500 mg/m2 on day 1. In the event of Cisplatin intolerance, Carboplatin AUC 5 or 6 IV was substituted. Eligible patients had completely resected, histologically confirmed Stage IB (tumors 4 cm or more), II, or IIIA NSCLC, and randomization was stratified according to disease stage and race (Asian versus non-Asian). A total of 231 patients had Stage II or IIIA disease, 116 in the Alectinib group and 115 in the chemotherapy group. The Primary end point was Disease Free Survival (DFS), tested hierarchically among patients with Stage II or IIIA disease and then in the Intention-To-Treat (ITT) population. Secondary end points included CNS Disease Free Survival, Overall Survival, and Safety. The median duration of follow up was 28 months.

The DFS among patients with Stage II or IIIA disease at 2 years was 93.8% in the Alectinib group and 63.0% in the chemotherapy group, and 88.3% and 53.3% respectively at 3 years. The Hazard Ratio for disease recurrence or death was 0.24 (P<0.001), which corresponds to a 76% lower risk with adjuvant Alectinib than with chemotherapy. This DFS benefit was seen consistently across prespecified subgroups, including those defined according to disease stage, race, sex, and smoking status. An exploratory analysis showed a clinically meaningful prolongation of CNS Disease Free Survival with Alectinib. Fewer patients in the Alectinib group had CNS recurrence compared to the chemotherapy group (3.1% versus 11%), consistent with the intracranial efficacy of Alectinib in advanced NSCLC. Overall Survival data were immature at the time of data-cutoff.

The authors concluded that Adjuvant Alectinib significantly improved Disease Free Survival, as compared with platinum-based chemotherapy, among patients with resected ALK-positive NSCLC of Stage IB, II, or IIIA, with few discontinuations due to adverse events. The researchers added that this study reinforces the need for implementation of biomarker testing for ALK alterations, across all stages of NSCLC.

Alectinib in Resected ALK-Positive Non–Small-Cell Lung Cancer. Wu Y-L, Dziadziuszko R, Ahn JS, et al. for the ALINA Investigators. N Engl J Med 2024;390:1265-1276.

FDA Approves ENHERTU® for Unresectable or Metastatic HER2-Positive Solid Tumors

RR

SUMMARY: The FDA on April 5, 2024, granted accelerated approval to ENHERTU® (fam-Trastuzumab Deruxtecan-nxki) for adult patients with unresectable or metastatic HER2-positive (IHC3+) solid tumors who have received prior systemic treatment, and have no satisfactory alternative treatment options. This tumor agnostic indication was approved based on Objective Response Rate and Duration of Response.

The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. HER2 is a Tyrosine Kinase Receptor growth-promoting protein and is involved in normal cell growth. It is expressed on the surface of various tissue cells throughout the body. In some cancers, HER2 expression is amplified or the cells have activating mutations. HER2 gene amplification can result in HER2 protein overexpression which is often associated with aggressive disease and poor prognosis. Approximately 15-20% of invasive breast cancers as well as advanced Gastric and GastroEsophageal (GE) junction cancers overexpress or have amplification of the HER2 oncogene. These patients often receive first line treatment with a combination of chemotherapy plus anti-HER2 antibody. Additionally, HER2 directed therapies have been used to treat lung and colorectal cancers. HER2 is an emerging biomarker in other solid tumor types including biliary tract, bladder, cervical, endometrial, ovarian and pancreatic cancers with HER2 positive expression rates varying from 1-28%. There are currently no approved HER2 directed therapies for these cancers following progression on standard of care therapies. There is an unmet need for effective therapies for these HER2 expressing tumor types.

ENHERTU® (Trastuzumab Deruxtecan) is an Antibody-Drug Conjugate (ADC) composed of a humanized monoclonal antibody specifically targeting HER2, with the amino acid sequence similar to Trastuzumab, a cleavable tetrapeptide-based linker, and a potent cytotoxic Topoisomerase I inhibitor as the cytotoxic drug (payload). ENHERTU® has a favorable pharmacokinetic profile and the tetrapeptide-based linker is stable in the plasma and is selectively cleaved by cathepsins that are up-regulated in tumor cells. Unlike KADCYLA® (ado-Trastuzumab emtansine), another ADC targeting HER2, ENHERTU® has a higher drug-to-antibody ratio (8 versus 4), released payload easily crosses the cell membrane with resulting potent cytotoxic effect on neighboring tumor cells regardless of target expression, and the released cytotoxic agent (payload) has a short half-life, thus minimizing systemic exposure.

The FDA approval was based on the efficacy of ENHERTU® in 192 adult patients with previously treated unresectable or metastatic HER2-positive (IHC 3+) solid tumors who were enrolled in one of three multicenter trials: DESTINY-PanTumor02 (NCT04482309), DESTINY-Lung01 (NCT03505710), and DESTINY-CRC02 (NCT04744831). All three trials excluded patients with a history of Interstitial Lung Disease /pneumonitis requiring treatment with steroids or Interstitial Lung Disease /pneumonitis at screening and clinically significant cardiac disease. Patients were also excluded for active brain metastases or ECOG performance status more than 1. Treatment was administered until disease progression or unacceptable toxicity. The major efficacy outcome measure in all three trials was confirmed Objective Response Rate (ORR), and an additional efficacy outcome was Duration of Response (DOR). All outcomes were assessed by Independent Central Review based on RECIST criteria.

DESTINY-PanTumor02 is a global, multicenter, multi-cohort, open-label, ongoing Phase II trial evaluating the efficacy and safety of ENHERTU® 5.4 mg/kg IV for the treatment of previously treated HER2 expressing tumors, including biliary tract, bladder, cervical, endometrial, ovarian, pancreatic cancer or other tumors. DESTINY-PanTumor02 enrolled 267 patients (N=267) at multiple sites in Asia, Europe and North America. Patients had received a median of two prior cancer therapies. In this study, the ORR was 51.4% and median DOR was 19.4 months.

DESTINY-Lung01 is a global, open-label, two-cohort, Phase II trial evaluating the efficacy and safety of ENHERTU® 6.4 mg/kg IV and 5.4 mg/kg IV in patients with HER2 mutant (cohort 2, N=91) or HER2 overexpressing (cohort 1 and 1a, N=90) (defined as IHC 3+ or IHC 2+) unresectable or metastatic non-squamous Non-Small Cell Lung Cancer (NSCLC), who had progressed after one or more systemic therapies. In this study, the ORR was 52.9% and the median DOR was 6.9 months.

DESTINY-CRC02 is a global, randomized, two arm, parallel, multicenter Phase II trial evaluating the efficacy and safety of two doses, 5.4 mg/kg IV or 6.4 mg/kg IV of ENHERTU® in patients with locally advanced, unresectable or metastatic HER2 positive colorectal cancer of BRAF wild-type, or RAS wild-type and RAS mutant tumor types, previously treated with standard therapy. The trial was conducted in two stages. In the first stage, patients (N=80) were randomized 1:1 to receive either 5.4 mg/kg IV or 6.4 mg/kg IV of ENHERTU®. In the second stage, additional patients (N=42) were enrolled in the 5.4 mg/kg IV arm. In DESTINY-CRC02, ORR was 46.9%, and DOR was 5.5 months.

The most common adverse reactions were cytopenias, nausea, vomiting, fatigue, liver function abnormalities and upper respiratory tract infection. The recommended dose of ENHERTU® for this indication is 5.4 mg/kg IV every 3 weeks until disease progression or unacceptable toxicity.

The forementioned trials validate HER2 as an actionable biomarker across a broad range of tumor types, and ENHERTU® has the potential to benefit patients with HER2 expressing advanced disease, who may face a poor prognosis and currently have limited treatment options.

https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-fam-trastuzumab-deruxtecan-nxki-unresectable-or-metastatic-her2.

Novel Prognostic Factors for Treatment-Free Remission in Chronic Myeloid leukemia

RR

SUMMARY: Chronic Myeloid Leukemia (CML) constitutes about 15% of all new cases of leukemia. The American Cancer Society estimates that about 9,280 new CML cases will be diagnosed in the United States in 2024 and about 1,280 patients will die of the disease. The hallmark of CML, the Philadelphia Chromosome (Chromosome 22), is a result of a reciprocal translocation between chromosomes 9 and 22, wherein the ABL gene from chromosome 9 fuses with the BCR gene on chromosome 22. As a result, the auto inhibitory function of the ABL gene is lost and the BCR-ABL fusion gene is activated resulting in cell proliferation and leukemic transformation of hematopoietic stem cells.

Chronic Myeloid Leukemia has long been a model for targeted cancer therapy, particularly through the development of Tyrosine Kinase Inhibitors (TKIs) targeting the BCR:ABL1 fusion gene. The presently available Tyrosine Kinase Inhibitors (TKI’s) approved in the United States including Imatinib, share the same therapeutic target, which is BCR-ABL kinase. Resistance to TKI’s can occur as a result of mutations in the BCR-ABL kinase domain or amplification of the BCR-ABL gene. With the availability of newer therapies for CML, monitoring response to treatment is important. This is best accomplished by measuring the amount of residual disease using Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Molecular response in CML is expressed using the International Scale (IS) as BCR-ABL%, which is the ratio between BCR-ABL and a control gene. BCR-ABL kinase domain point mutations are detected using the mutational analysis by Sanger sequencing. Majority of the patients receiving a TKI following diagnosis of CML achieve a Complete Cytogenetic Response (CCyR) within 12 months following commencement of therapy and these patients have a life expectancy similar to that of their healthy counterparts. Previously published studies have shown that Deep Molecular Response (BCR-ABL <0.01% on the International Scale-MR4) is a new molecular predictor of long term survival in CML patients, and this was achieved in a majority of patients treated with TKIs. Further, it has been shown from previous observations, that a subgroup of CML patients experiencing deeper responses (MR3, MR4, and MR4.5), may stay in unmaintained remission even after treatment discontinuation. Despite this observation, precise criteria for stopping CML therapy have not been clearly defined.

Discontinuing TKI therapy after a Deep Molecular Response among patients with CML can potentially improve quality of life, minimize long term toxicities as well as drug-drug interactions, and reduce financial burden. Stopping TKI therapy among CML patients appears to be safe and feasible in over 50% of the patients, although about 20% of these patients experience TKI withdrawal syndrome manifesting as musculoskeletal symptoms. Discontinuation of TKI therapy should only be considered in consenting patients after a thorough discussion of the potential risks and benefits. TKIs have revolutionized the prognosis and quality of life for patients with CML, leading to a new treatment goal of achieving Treatment-Free Remission (TFR).

The European Stop Kinase Inhibitors (EURO-SKI) study is the largest clinical trial conducted to assess the safety of stopping Tyrosine Kinase Inhibitor therapy in patients with CML, whose leukemia was in stable Deep Molecular Response (DMR). The researchers presented the final analysis of the EURO-SKI trial after 3 years of follow up and highlighted the prognostic factors for short- and long-term molecular response maintenance. This comprehensive study evaluated the effects of stopping TKI treatment (Imatinib, Nilotinib or Dasatinib), in patients who had been on therapy for at least 3 years and had confirmed DMR, defined as BCR:ABL1-transcripts 0.01% or less on the International Scale for at least 12 months. The Primary outcomes of the study were the maintenance of Major Molecular Response (MMR), defined as BCR:ABL1 0.1% or less (MR3), at 6 and 36 months after stopping TKIs (Molecular Recurrence Free Survival).

In this study, 868 patients with Chronic Phase CML were screened, and 728 patients were included in the baseline analysis. The final analysis revealed that 61% of patients remained in MMR at 6 months, and 46% remained in MMR at 36 months after stopping TKI treatment. Several factors were identified as significant predictors of MMR maintenance. Longer duration of TKI treatment and DMR before stopping TKI treatment were associated with a higher likelihood of maintaining MMR at 6 months. Additionally, the type of BCR:ABL1 transcript emerged as a prognostic factor, with patients having transcript type e14a2 alone or in combination with e13a2 showing a significantly higher probability of maintaining MMR. For MMR maintenance between 6 and 36 months, the duration of TKI treatment (but not DMR duration) before stopping TKI treatment, and disease characteristics at diagnosis, including percentage of peripheral blood blast cells and platelet count at diagnosis, were significant factors influencing MMR maintenance. Among 315 patients evaluated at 36 months, the Molecular Recurrence Free Survival was 76%. Multivariate analysis over the entire 36-month trial period identified duration of TKI treatment, duration of DMR (Deep Molecular Response) while receiving TKI, percentage of peripheral blood blast cells at diagnosis, and transcript type (e14a2 plus e13a2 had a higher probability of maintaining MMR over 36 months than e13a2 alone) as independent factors for MMR maintenance.

The findings of the EURO-SKI trial have important implications and represent a significant milestone for the management of CML. They highlight the importance of considering not only the duration of TKI treatment but also disease characteristics and transcript type when predicting treatment-free remission. This study represents a significant step forward in understanding the factors influencing Treatment-Free Remission in CML patients, and may help guide clinical decision-making in the future.

European Stop Tyrosine Kinase Inhibitor Trial (EURO-SKI) in Chronic Myeloid Leukemia: Final Analysis and Novel Prognostic Factors for Treatment-Free Remission. Mahon F-X, Pfirrmann M, Dulucq S, et al. on behalf of the EURO-SKI Investigators. Journal of Clinical Oncology. March 12, 2024. https://doi.org/10.1200/JCO.23.01647.

FDA Approves RYBREVANT® in Combination with Chemotherapy for Advanced NSCLC with EGFR Exon 20 Insertion Mutations

RR

SUMMARY: The FDA on March 1, 2024, approved Amivantamab-vmjw (RYBREVANT®) with Carboplatin and Pemetrexed for the first-line treatment of locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) exon 20 insertion mutations, as detected by an FDA-approved test. The FDA also granted traditional approval to Amivantamab-vmjw for adult patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations, as detected by an FDA-approved test, whose disease has progressed on or after platinum-based chemotherapy. FDA previously granted accelerated approval for this indication based on Phase 1 CHRYSALIS study.

The American Cancer Society estimates that for 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer.

Approximately 10-15% of Caucasian patients and 35-50% of Asian patients with Adenocarcinomas, harbor activating EGFR mutations, and 90% of these mutations are either exon 19 deletions or L858R substitution mutation in exon 21. EGFR exon 20 insertion mutations are the third most common after L858R and exon 19 deletions and occur in about 2-3% patients with NSCLC and are insensitive to EGFR Tyrosine Kinase Inhibitors (TKIs) due to an altered conformation of the kinase active site. Next-Generation sequencing provides an alternative to Polymerase Chain Reaction (PCR)-based tests, which fail to identify 50% or more of exon 20 insertion mutations. Patients with EGFR exon 20 insertion mutations have a 5-year Overall Survival (OS) of 8% in the frontline setting, compared to an OS of 19% for patients with EGFR exon 19 deletions or L858R mutations. There is therefore a clinically unmet need for this patient group, as there are no approved targeted therapies available, and platinum-doublet chemotherapy remains the standard of care for these patients.

Amivantamab (RYBREVANT®) is a fully human bispecific antibody directed against EGFR and MET receptors, with immune cell-directing activity. Amivantamab binds extracellularly and simultaneously blocks ligand-induced phosphorylation of EGFR and c-MET, inhibiting tumor growth and promoting tumor cell death. Further, Amivantamab downregulates receptor expression on tumor cells thus preventing drug resistance mediated by new emerging mutations of EGFR or c-MET. By binding to the extracellular domain of the receptor protein, Amivantamab can bypass primary and secondary TKI resistance at the active site. Additionally, Amivantamab has been shown to engage macrophages, monocytes, and Natural Killer cells through its Fc domain. Amivantamab in combination with Carboplatin and Pemetrexed demonstrated synergy, with improvement in Response Rates, in previously published studies.

PAPILLON trial is an international, randomized, Phase III study, conducted to assess the efficacy and safety of Amivantamab plus chemotherapy as compared with standard chemotherapy alone, as first-line treatment, in patients with advanced NSCLC with EGFR exon 20 insertions. In this study, 308 patients (N=308) were randomly assigned 1:1 to receive Amivantamab plus chemotherapy (N=153) or chemotherapy alone (N=155), given in 3 week cycles. Amivantamab was given at a dose of 1400 mg (1750 mg for a body weight of 80 kg or more) IV weekly for the first 4 weeks, with the first infusion split over 2 days (at a dose of 350 mg on cycle 1, day 1, and the remainder on cycle 1, day 2). Starting at cycle 3 (week 7), the dose of Amivantamab was increased to 1750 mg IV (2100 mg for a body weight of 80 kg or more) administered every 3 weeks until disease progression. Carboplatin was administered at AUC 5 IV every 3 weeks for up to 4 cycles. Pemetrexed was administered at a dose of 500 mg/m2 IV every 3 weeks until disease progression. Both treatment groups were well balanced and the patients mutational status was determined by local testing of tissue samples in 92% of cases, and plasma samples in 8% of cases. Patients with treated brain metastases were eligible if they were asymptomatic. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive Amivantamab monotherapy. The Primary end point was Progression Free Survival (PFS) as determined by Blinded Independent Central Review. Secondary end points included Objective Response Rate (ORR), Overall Survival (OS), Duration of Response and Safety.

At a median follow-up of 14.9 months, the median PFS was significantly longer in the Amivantamab plus Chemotherapy group and was 11.4 months, compared to 6.7 months in the chemotherapy alone group (HR=0.40; P<0.001). At 18 months, the PFS in the Amivantamab plus chemotherapy group was 31% and 3% in the chemotherapy group. The Objective Response was 73% in the Amivantamab plus chemotherapy group and 47% in the chemotherapy alone group (P<0.001). Overall Survival results were immature at the time of current analysis, with a trend toward improvement in Overall Survival despite a high rate of crossover for the control arm (42%).

The most common adverse events associated with Amivantamab plus chemotherapy were reversible hematologic and EGFR-related toxic effects and included rash, nail toxicity, stomatitis, infusion-related reaction, fatigue, diarrhea, nausea and vomiting. Approximately 7% of patients discontinued Amivantamab due to adverse reactions.

It was concluded that Amivantamab in combination with chemotherapy resulted in superior efficacy as compared with chemotherapy alone, in previously untreated advanced NSCLC patients with EGFR exon 20 insertions.

Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions. Zhou C, Tang K-J, Cho BC, et al. for the PAPILLON Investigators. N Engl J Med 2023;389:2039-2051.

TUKYSA® Plus KADCYLA® in Advanced HER2-Positive Breast Cancer

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that in the USA, approximately 310,720 new cases of female breast cancer will be diagnosed in 2024, and about 42,250 individuals will die of the disease, largely due to metastatic recurrence.

The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of invasive breast cancers overexpress HER2/neu oncogene, which is a negative predictor of outcomes without systemic therapy. Patients with HER2-positive metastatic breast cancer are often treated with anti-HER2 targeted therapy along with chemotherapy, irrespective of hormone receptor status, and this has resulted in significantly improved treatment outcomes. HER2-targeted therapies include HERCEPTIN® (Trastuzumab), TYKERB® (Lapatinib), PERJETA® (Pertuzumab), KADCYLA® (ado-Trastuzumab emtansine, T-DM1), ENHERTU® (Trastuzumab deruxtecan) and MARGENZA® (Margetuximab). Dual HER2 blockade with HERCEPTIN® and PERJETA®, given along with chemotherapy (with or without endocrine therapy), as first line treatment, in HER2-positive metastatic breast cancer patients, was shown to significantly improve Progression Free Survival (PFS) as well as Overall Survival (OS). The superior benefit with dual HER2 blockade has been attributed to differing mechanisms of action and synergistic interaction between HER2 targeted therapies. Patients progressing on Dual HER2 blockade often receive KADCYLA® which results in an Objective Response Rate (ORR) of 44% and a median PFS of 9.6 months, when administered after HERCEPTIN® and a Taxane.

With advances in systemic therapies for this patient population, the incidence of brain metastases as a sanctuary site has increased. Approximately 50% of patients with HER2-positive metastatic breast cancer develop brain metastases. However, systemic HER2-targeted agents, including Tyrosine Kinase Inhibitors, as well as chemotherapy have limited antitumor activity in the brain. Local therapeutic interventions for brain metastases include neurosurgical resection and Stereotactic or Whole-Brain Radiation Therapy. There is a high unmet need for systemic treatment options to treat established brain metastases and reduce the risk for progression in the Central Nervous System (CNS).

TUKYSA® (Tucatinib) is an oral Tyrosine Kinase Inhibitor that is highly selective for the kinase domain of HER2 with minimal inhibition of Epidermal Growth Factor Receptor. In the HER2CLIMB international, randomized, double-blind, placebo-controlled trial, a combination of TUKYSA® plus HERCEPTIN® and XELODA® (Capecitabine) was compared with placebo plus HERCEPTIN® and XELODA®. TUKYSA® combination significantly improved Progression Free and Overall Survival in heavily pretreated patients, including those with brain metastases.

The HER2CLIMB-02 trial is a randomized, double-blind, placebo-controlled Phase III trial conducted to evaluate the efficacy and safety of the combination of TUKYSA® and KADCYLA® in patients with metastatic HER2-positive breast cancer, particularly those with brain metastases. This study focused on patients with brain metastases, given the limited options for managing breast cancer brain metastases. In this study, 463 patients (N=463) with unresectable locally advanced or metastatic HER2-positive breast cancer were randomly assigned in a 1:1 ratio to receive either 21-day cycles of either TUKYSA® at 300 mg orally twice a day and KADCYLA® 3.6 mg/kg IV every 3 weeks (N=228) or KADCYLA® and placebo (N=235). Both treatment groups were well balanced. The median age was 55 years, eligible patients had been previously treated with HERCEPTIN® and a Taxane in any setting, and trial entry criteria included enrollment of previously treated, stable, progressing, or untreated brain metastases not requiring immediate local therapy. Approximately 40% of all patients had baseline active or stable brain metastasis, and the researchers noted that this was the second large trial, prospectively designed to evaluate systemic therapy in patients with brain metastases. The Primary endpoint was Progression Free Survival (PFS).

At a median follow up was 24.4 months, the combination of TUKYSA® plus KADCYLA® showed a significant improvement in median PFS compared to KADCYLA® alone. The median time to disease progression or death was 9.5 months with TUKYSA® plus KADCYLA® versus 7.4 months with KADCYLA® alone, suggesting a 24% reduction in the risk of disease progression or death with the combination treatment. Among patients with brain metastasis at baseline, the median time to disease progression or death was 7.8 months with the TUKYSA® plus KADCYLA® combination versus 5.7 months with KADCYLA® alone, suggesting a 36% reduction in the risk of disease progression or death with the combination. Further, patients in the TUKYSA® plus KADCYLA® group had a higher Objective Response Rate compared to the control arm (42% versus 36.1%). Overall survival data were immature at the time of this analysis. The combination treatment group reported more treatment related adverse events which included nausea, diarrhea, fatigue and liver function abnormalities.

It was concluded that the combination of TUKYSA® and KADCYLA® demonstrated a statistically significant improvement in Progression Free Survival, compared to KADCYLA® alone, supporting its efficacy in patients with HER2-positive metastatic breast cancer. This study was prospectively designed to evaluate novel systemic therapies in patients with brain metastases, and findings from this study suggested that the combination of TUKYSA® and KADCYLA® could be a favorable treatment option, especially for patients with active or progressing brain metastases. It should be noted that this study did not directly compare the experimental regimen of TUKYSA® and KADCYLA® with other established regimens like TUKYSA® plus HERCEPTIN® and XELODA® or regimens containing ENHERTU®.

HER2CLIMB-02: randomized, double-blind phase 3 trial of tucatinib and trastuzumab emtansine for previously treated HER2-positive metastatic breast cancer. Hurvitz SA, Loi S, O’Shaughnessy J, et al. Presented at the 2023 San Antonio Breast Cancer Symposium; December 5-9, 2023; San Antonio, TX. Session GS01-10.

Sotorasib plus Panitumumab in Refractory Colorectal Cancer with Mutated KRAS G12C

RR

SUMMARY: Colorectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 153,020 new cases of CRC were diagnosed in the United States in 2023 and about 52,550 patients died of the disease. The lifetime risk of developing CRC is about 1 in 23.

Approximately 15-25% of the patients with CRC present with metastatic disease at the time of diagnosis (synchronous metastases) and 50-60% of the patients with CRC will develop metastatic disease during the course of their illness. First line treatment of metastatic CRC includes Oxaliplatin or Irinotecan, in combination with a Fluoropyrimidine and Leucovorin (FOLFOX or FOLFIRI respectively), along with a VEGF targeting agent such as Bevacizumab or EGFR targeting agents such as Cetuximab and Panitumumab. Patients with Stage IV colorectal cancer are now routinely analyzed for extended RAS and BRAF mutations. KRAS mutations are predictive of resistance to EGFR targeted therapy. Patients who progress following these therapies are considered to have refractory disease. These patients sometimes are rechallenged with previously administered chemotherapeutic agents, but often receive STIVARGA® (Regorafenib), an oral multikinase inhibitor with antiangiogenic activity, or LONSURF® (a fixed dose combination of Trifluridine and Tipiracil). These therapies however have shown limited efficacy.

The KRAS (Kirsten rat sarcoma viral oncogene homologue) proto-oncogene encodes a protein that is a member of the small GTPase super family. The KRAS gene provides instructions for making the KRAS protein, which is a part of a signaling pathway known as the RAS/MAPK pathway. By relaying signals from outside the cell to the cell nucleus, the protein instructs the cell to grow, divide and differentiate. KRAS gene is in the Ras family of oncogenes, which also includes two other genes, HRAS and NRAS. When mutated, oncogenes have the potential to change normal cells cancerous. KRAS is the most frequently mutated oncogene in human cancers and are often associated with resistance to targeted therapies and poor outcomes. The KRAS G12C mutation occurs in approximately 12-15% of Non Small Cell Lung Cancers (NSCLC) and in 3-5% of colorectal cancers and other solid cancers. G12C is a single point mutation with a Glycine-to-Cysteine substitution at codon 12. This substitution favors the activated state of KRAS, amplifying signaling pathways that lead to oncogenesis. Currently, no targeted therapies driven by a positive-selection biomarker are approved specifically for the treatment of patients with KRAS-mutated colorectal cancer.

Sotorasib (LUMAKRAS&reg;) is a small molecule that specifically and irreversibly inhibits KRAS G12C protein and traps KRAS G12C in the inactive GDP-bound state, thus blocking downstream proliferation and survival signaling. Unlike the efficacy of single-agent KRAS G12C inhibitors in Non Small Cell Lung Cancer with KRAS G12C mutation, KRAS G12C inhibition alone has limited activity in patients with colorectal cancer. This has been attributed to upstream reactivation of the Epidermal Growth Factor Receptor (EGFR) pathway resulting in treatment-induced resistance, following selective inhibition of KRAS G12C. However, dual KRAS G12C and EGFR blockade can overcome treatment resistance in patients with colorectal cancer with KRAS G12C mutation. In the CodeBreaK 101 Phase 1b trial involving patients with chemorefractory colorectal cancer with mutated KRAS G12C, the Response Rate was 30% with Sotorasib plus Panitumumab, as compared with 9.7% with Sotorasib monotherapy.

CodeBreaK 300 trial is an international, multicenter, open-label, randomized, active-controlled Phase III study, conducted to evaluate the efficacy and safety of two different doses of Sotorasib (960 mg and 240 mg) in combination with Panitumumab as compared with the investigator’s choice of standard-care therapy (Trifluridine-Tipiracil or Regorafenib) in patients with chemorefractory metastatic colorectal cancer with KRAS G12C mutation. A lower dose of Sotorasib 240 mg orally once daily was tested in this study because of the nonlinear pharmacokinetic properties of Sotorasib. A total of 160 patients were randomly assigned in a 1:1:1 ratio to receive Sotorasib 960 mg orally once daily plus Panitumumab 6 mg/kg IV every 2 weeks (the 960 mg Sotorasib/Panitumumab group; N=53), Sotorasib 240 mg orally once daily plus Panitumumab (the 240 mg Sotorasib/Panitumumab group; N=53), with each treatment cycle repeating every 28 days, or the investigator’s choice of standard of care therapy which could be either Trifluridine-Tipiracil 35 mg/m2 (up to a maximum of 80 mg per dose) orally twice daily on days 1-5 and days 8-12 every 28 days, or Regorafenib 160 mg orally once daily for the first 21 days of each 28-day cycle (N=54). Treatment continued until disease progression or unacceptable toxicities. The median age was 61 years and majority of patients had more than 2 or more lines of previous anti-cancer therapy. KRAS G12C mutation was confirmed by prospective central molecular testing. Randomization was stratified according to previous use of antiangiogenic therapy, the time from initial diagnosis of metastatic disease to randomization and ECOG-PS. The Primary end point was Progression Free Survival (PFS) as assessed by Blinded Independent Central Review (BICR). Key Secondary end points included Overall Survival (OS) and Objective Response Rate (ORR).

After a median follow up of 7.8 months, both Sotorasib combinations (960 mg and 240 mg) plus Panitumumab demonstrated significantly longer PFS compared to standard of care therapy. The median PFS was 5.6 months and 3.9 months in the 960 mg Sotorasib/Panitumumab and 240 mg Sotorasib/Panitumumab groups, respectively, as compared with 2.2 months in the standard of care group (HR for 960 mg group=0 49; P=0.006) (HR for 240 mg group=0.58; P=0.03). The improvement in PFS was observed across key subgroups, including tumor sideness/primary tumor location, prior lines of therapy, and the presence or absence of liver metastases. The Objective Response Rate was 26.4%, 5.7%, and 0% in the 960 mg Sotorasib/Panitumumab, 240 mg Sotorasib/Panitumumab, and standard of care groups, respectively. Overall survival data is immature. While this trial was not powered to compare the two Sotorasib/Panitumumab groups directly, the 960-mg dose appeared to yield more clinically significant benefits than the 240-mg dose, across all efficacy endpoints, without additional toxic effects. Grade 3 or higher treatment-related adverse events occurred in 35.8%, 30.2%, and 43.1% of patients, respectively. Skin-related toxic effects and hypomagnesemia were the most common adverse events observed with Sotorasib/Panitumumab.

It was concluded from this study that both doses of Sotorasib (960 mg and 240 mg) in combination with Panitumumab resulted in significantly longer Progression Free Survival and a higher incidence of Response Rate than standard treatment. Ongoing analysis and longer follow up will provide additional insights into Overall Survival outcomes.

Sotorasib plus Panitumumab in Refractory Colorectal Cancer with Mutated KRAS G12C. Fakih MG, Salvatore L, Esaki T, et al. N Engl J Med 2023;389:2125-2139.

FDA Approves AUGTYRO® for ROS1-positive Non-Small Cell Lung Cancer

RR

SUMMARY: The FDA on November 15, 2023, approved AUGTYRO® (Repotrectinib) for locally advanced or metastatic ROS1-positive Non-Small Cell Lung Cancer (NSCLC). This is the first FDA approval that includes patients with ROS1-positive NSCLC who have previously received a ROS1 Tyrosine Kinase Inhibitor (TKI), in addition to patients who are TKI naïve.

Approximately 1-2% of lung adenocarcinomas harbor ROS1 gene rearrangements. ROS1 gene is located on chromosome 6q22 (long arm of chromosome 6) and plays an important role in cell growth and development. ROS1 gene fusion with another gene results in a mutated DNA sequence which then produces an abnormal protein responsible for unregulated cell growth and cancer. ROS1 gene rearrangement has been identified as a driver mutation in Non Small Cell Lung Cancer with adenocarcinoma histology. This is more common in nonsmokers or in light smokers (<10 pack years) who are relatively young (average age of 50 years), and thus share similar characteristics with ALK-positive patients. ROS1 mutations have been also been associated with Cholangiocarcinoma (Bile duct cancer) and Glioblastoma multiforme. ROS1 rearrangements are mutually exclusive with other oncogenic mutations found in NSCLC such as EGFR mutations, KRAS mutations and ALK rearrangement. The presence of a ROS1 rearrangement can be detected by Fluorescence In Situ Hybridization (FISH), ImmunoHistoChemistry (IHC), Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and Next Generation-Sequencing. There are currently two FDA-approved treatment options for ROS1-positive metastatic NSCLC- Crizotinib and Entrectinib.

Repotrectinib is a next-generation TKI targeting ROS1 or NTRK-positive locally advanced or metastatic solid tumors, including NSCLC. Repotrectinib was designed to improve durability of response and with favorable properties to enhance intracranial activity.

The FDA approval was based on the results of the TRIDENT-1 global, multicenter, single-arm, Phase I/II, open-label, multi-cohort clinical trial, designed to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of Repotrectinib, in patients with advanced solid tumors, including locally advanced or metastatic NSCLC. Phase I component of the trial evaluated the safety and pharmacokinetics, whereas in the Phase II component of the study included six distinct expansion cohorts, including TKI-naïve and TKI-pretreated patients with ROS1-positive locally advanced or metastatic NSCLC and NTRK-positive advanced solid tumors. Eligibility requirements included locally advanced or metastatic solid tumors harboring ROS1 or NTRK1-3 gene fusions. Patients with asymptomatic CNS metastases were allowed. Patients received Repotrectinib 160 mg once daily, orally for 14 days, followed by 160 mg twice daily until disease progression or unacceptable toxicities. The Primary endpoint was Overall Response Rate (ORR) as assessed by Blinded Independent Central Review (BICR), and Secondary endpoints included Duration of Response (DOR), Progression Free Survival (PFS), Overall Survival (OS) and Clinical Benefit Rate (CBR). The efficacy was evaluated in ROS1 TKI-naïve patients (N=71) who received up to one prior line of platinum-based chemotherapy and/or immunotherapy, and in patients who received one prior ROS1 TKI with no prior platinum-based chemotherapy or immunotherapy (N=56).

In TKI-naïve patients with median follow-up of 24.0 months, the confirmed Objective Response Rate by BICR was 79%, median Duration of Response was 34.1 months and PFS was 35.7 months. In patients with measurable brain metastases at baseline (N=9), intracranial ORR per BICR was 89% and these responses were prolonged.

In patients who received one prior ROS1 TKI with no prior chemotherapy or immunotherapy, at a median follow-up of 21.5 months, the confirmed Objective Response Rate by BICR was 38%, median Duration of Response was 14.8 months and PFS was 9.0 months. In this subset of patients with measurable brain metastases at baseline (N=13), intracranial ORR per BICR was 38%.

The most common adverse reactions were fatigue, dizziness, dyspnea, dysgeusia, peripheral neuropathy, constipation, ataxia, cognitive disorders, and muscular weakness.

It was concluded that the TRIDENT-1 trial demonstrated the efficacy of Repotrectinib in both, TKI-naïve and previously treated patients, showcasing high response rates and durable outcomes. These data will provide physicians with valuable insights into the clinical benefits with Repotrectinib , paving the way for its potential adoption as a new standard of care, in the treatment of ROS1-positive NSCLC. TRIDENT-1 trial is ongoing to assess long term outcomes and additional endpoints across patient populations with ROS1-positive locally advanced or metastatic NSCLC, and NTRK-positive advanced solid tumors.

Repotrectinib in patients with ROS1 fusion-positive (ROS1+) NSCLC: Update from the pivotal phase 1/2 TRIDENT-1 trial. Cho BC, Camidge DR, Lin JJ, et al. Presented at the IASLC 2023 World Conference on Lung Cancer; September 10-12, 2023; Singapore. Abstract OA03.06.

Biomarker Driven ELAHERE® in FR alpha-Positive, Platinum-Resistant Ovarian Cancer

RR

SUMMARY: It is estimated that in the United States, approximately 19,710 women will be diagnosed with ovarian cancer in 2023, and 13,270 women will die of the disease. Ovarian cancer ranks fifth in cancer deaths among women, and accounts for more deaths than any other cancer of the female reproductive system. Approximately 75% of the ovarian cancer patients are diagnosed with advanced disease. About 85% of all ovarian cancers are epithelial in origin, and 70% of all epithelial ovarian cancers are High-Grade serous adenocarcinomas. Patients with newly diagnosed advanced ovarian cancer are often treated with platinum-based chemotherapy following primary surgical cytoreduction. Approximately 70% of these patients will relapse within the subsequent 3 years and are incurable, with a 5-year Overall Survival (OS) rate of about 20-30%. Treatment options for patients with platinum-resistant ovarian cancer are limited, and patients are often treated with single-agent chemotherapy, with an Overall Response Rate (ORR) of between 4% and 13%, short duration of response, and significant toxicities.

Approximately 35-40% of ovarian cancer patients express high levels of Folate Receptor alpha (FR alpha), and this expression correlates with advanced stages of disease and more malignant phenotypes. There is limited expression of Folate Receptor alpha in normal tissues and is limited to the choroid plexus, proximal renal tubules, placenta, and endometrium. Testing for Folate Receptor alpha can be performed on fresh or archived tissue.

ELAHERE® (Mirvetuximab soravtansine-gynx) is a first-in-class Antibody Drug Conjugate (ADC), directed against FR alpha, a cell-surface protein highly expressed in ovarian cancer. It is comprised of a Folate Receptor alpha-binding antibody, cleavable linker, and the maytansinoid payload DM4, which is a potent tubulin inhibitor, disrupting microtubule formation, and thereby designed to kill the targeted cancer cells. Microtubules are major components of the cytoskeleton that give shape and structure to cells. ELAHERE® is the first FDA approved ADC for platinum-resistant disease. In the single-arm SORAYA trial, ELAHERE® demonstrated an ORR of 31.7% and median Duration of Response of 6.9 months, in patients with platinum-resistant ovarian cancer, and prior Bevacizumab exposure. These response rates were consistently seen regardless of the number of prior therapies or the use of a prior PARP inhibitor. As a result, the FDA in November 2022 granted accelerated approval to ELAHERE®.

MIRASOL is a confirmatory randomized Phase III trial, conducted to evaluate the efficacy and safety of ELAHERE® versus Standard-of-Care chemotherapy, in patients with pretreated, platinum-resistant ovarian, peritoneal, or fallopian tube cancer, whose tumors express high levels of FR alpha. In this study, 453 eligible patients (N=453) were randomized 1:1 to receive ELAHERE® 6 mg/kg (based on adjusted ideal body weight) IV infusion once every three weeks, until disease progression or unacceptable toxicity (N=227), or investigators choice of single-agent chemotherapy – Paclitaxel, Pegylated Liposomal Doxorubicin, or Topotecan (N=226)). Both treatment groups were well balanced. Approximately 13% of patients had BRCA mutations, 14% of patients had one prior line of therapy, 39% had two prior lines and 47% had three prior lines of therapy. About 62% received prior Bevacizumab and 55% received prior therapy with PARP inhibitors. The Primary efficacy endpoint was Progression Free Survival (PFS). Secondary endpoints included Overall Response Rate (ORR), Overall Survival (OS), and Patient-Reported Outcomes in hierarchical order, as well as Safety and tolerability. The median follow up was 13.1 months.

This study met its Primary and key Secondary endpoints with statistically significant improvement in PFS, ORR and OS. The PFS in the ELAHERE® group was 5.62 months compared to 3.98 months in the chemotherapy group (HR=0.65; P<0.0001). The ORR was also higher in the ELAHERE® group at 42% compared with 16% in the chemotherapy group (P<0.0001). The median Overall Survival rate was 16.46 months among patients who received ELAHERE® compared with 12.75 months among those who received single-agent chemotherapy (HR=0.67; P=0.005). The PFS and OS outcomes favored the ELAHERE® group, irrespective of prior exposure to Bevacizumab. Treatment with ELAHERE® was associated with a lower rate of Grade 3 or more Adverse Events and a lower discontinuation rate (9% compared with 16% for the chemotherapy group). The most common adverse reactions including laboratory abnormalities associated with ELAHERE® were vision impairment, keratopathy, fatigue, nausea, peripheral neuropathy, increase in ALT and AST and cytopenias. Product labeling includes a boxed warning for ocular toxicity. The ocular events were reversible and primarily included low-grade blurred vision and keratopathy, which were managed with protocol-defined dose modifications. Approximately 60% of patients with symptoms had resolution prior to their next cycle of treatment, and less than 1% of patients discontinued therapy due to an ocular event.

It was concluded that treatment with ELAHERE® demonstrated a statistically significant improvement in Progression Free Survival and Overall survival, compared to chemotherapy, in patients with platinum-resistant ovarian cancer and high FR alpha expression, independent of Bevacizumab use, and may be the new standard-of-care for this patient group. ELAHERE® is the first FDA-approved Antibody Drug Conjugate and biomarker directed therapy for ovarian cancer, since the approval of PARP inhibitors.

Mirvetuximab Soravtansine in FRα-Positive, Platinum-Resistant Ovarian Cancer. Moore KN, Angelergues A, Konecny GE, et al. N. Engl J Med 2023;389:2162-2174

FDA Approves TRUQAP® with Fulvestrant for Advanced Breast Cancer

RR

SUMMARY: The FDA on November 16, 2023, approved Capivasertib (TRUQAP®) with Fulvestrant for adult patients with Hormone Receptor-positive (HR-positive), Human Epidermal growth factor Receptor 2-negative (HER2-negative) locally advanced or metastatic breast cancer with one or more PIK3CA/AKT1/PTEN-alterations, as detected by an FDA-approved test, following progression on at least one endocrine-based regimen in the metastatic setting or recurrence on or within 12 months of completing adjuvant therapy. FDA also approved the FoundationOne® CDx assay as a companion diagnostic device to identify patients with breast cancer for treatment with Capivasertib with Fulvestrant.

Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S. About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor-positive (HR-positive), HER2-negative breast cancer is the most frequently diagnosed molecular subtype. The most common subtype of metastatic breast cancer is HR-positive, HER2-negative breast cancer (65% of all metastatic breast tumors), and these patients are often treated with anti-estrogen therapy as first line treatment. However, resistance to hormonal therapy occurs in a majority of the patients, with a median Overall Survival (OS) of 36 months. With the development of Cyclin Dependent Kinases (CDK) 4/6 inhibitors, endocrine therapy plus a CDK4/6 inhibitor is the mainstay, for the management of HR-positive, HER2-negative metastatic breast cancer, as first line therapy. Even with this therapeutic combination, most patients will eventually experience disease progression due to resistance to endocrine therapy. A therapy overcoming endocrine resistance is an area of active research in the breast cancer space.

The P13K/Akt pathway is a growth-regulating cellular signaling pathway, which in many human cancers is overactivated. Inhibition of the PI3K/Akt signaling pathway leads to inhibition of cell proliferation and induction of apoptosis in tumor cells. A wide range of solid and hematological malignancies show dysregulated PI3K/AKT/mTOR/PTEN signaling due to mutations in the genes involved. Overactivation of the PI3K-AKT-PTEN signaling pathway occurs in approximately 50% of HR-positive, HER2-negative breast cancers by means of activating mutations in PIK3CA and AKT1 and inactivating alterations in PTEN. These alterations may be present at the time of cancer recurrence, and can also be acquired following previous treatment including with CDK4/6 inhibitors. Further, AKT signaling may also be activated in the absence of genetic alterations in patients with endocrine resistance.

Capivasertib is a novel, first-in-class, orally bioavailable small molecule inhibitor of the serine/threonine protein kinase AKT (protein kinase B), with potential antineoplastic activity. It is a potent, selective ATP-competitive inhibitor of all three AKT isoforms (AKT1/2/3). By targeting AKT, the key node in the PIK3/AKT signaling network, Capivasertib potentially may be used as monotherapy or combination therapy, for a variety of human cancers. In the Phase II FAKTION trial, Capivasertib in combination with Fulvestrant significantly improved Progression Free and Overall Survival as compared with Fulvestrant alone, among postmenopausal women with HR-positive advanced breast cancer, who had previously received endocrine therapy. The researchers conducted the CAPItello-291 trial to determine whether the addition of Capivasertib to Fulvestrant would improve outcomes in patients with HR-positive breast cancer whose tumors had developed resistance to an Aromatase Inhibitor and CDK4/6 inhibitor.

CAPItello-291 is a randomized, double-blind Phase III trial in which 708 adult patients with histologically confirmed HR-positive, HER2-low or negative breast cancer, whose disease has recurred or progressed during or after Aromatase Inhibitor therapy, with or without a CDK4/6 inhibitor, were enrolled. Patients were randomly assigned 1:1 to receive either the Capivasertib plus Fulvestrant (N=355) arm or the placebo plus Fulvestrant arm (N=353). Patients in the study group received Capivasertib 400 mg orally twice daily for 4 days on and 3 days off along with Fulvestrant 500 mg IM on days 1 and 15 during cycle 1, then every 4 weeks thereafter. The present dosing of Capivasertib was chosen based on tolerability and the degree of target inhibition in early phase trials. The control group received matched placebo along with Fulvestrant. Patients received therapy until disease progression or unacceptable toxicity. In this trial, patients could have received up to two prior lines of endocrine therapy and up to 1 line of chemotherapy for locally advanced or metastatic disease. Approximately 40% of tumors (N=289) had PI3K/AKT/PTEN alterations. Both treatment groups were well balanced. Stratification factors included liver metastases and prior CDK 4/6 inhibitor. The dual Primary endpoints were Progression Free Survival (PFS) in the overall patient population and in a subgroup of patients whose tumors have qualifying alterations in the PIK3CA, AKT1 or PTEN genes. Secondary endpoints included Overall Survival (OS) and Objective Response Rate (ORR).

The trial met both Primary endpoints, improving PFS in the overall patient population and in a prespecified biomarker subgroup of patients whose tumors had qualifying alterations in the AKT pathway genes. In the overall trial population, patients treated with Capivasertib plus Fulvestrant had a median PFS of 7.2 months, compared to 3.6 months in patients treated with placebo plus Fulvestrant (HR=0.60; P<0.001). This amounted to a 40% lower risk of disease progression among patients who received Capivasertib plus Fulvestrant. Among patients with AKT pathway mutations treated with Capivasertib plus Fulvestrant, the median PFS was 7.3 months versus 3.1 months in the placebo group (HR=0.50; P<0.001), reducing the risk of disease progression or death by 50%, versus placebo plus Fulvestrant. An exploratory analysis of PFS in the 313 patients whose tumors did not have a PIK3CA, AKT1 or PTEN-alteration showed a HR of 0.79, suggesting that the difference in the overall population was primarily attributed to the results seen in the population of patients whose tumors have PIK3CA, AKT1 or PTEN-alteration. The benefit from Capivasertib was consistent across key clinically relevant subgroups, including patients previously treated with CDK4/6 inhibitor and patients with liver metastases.
The Objective Response Rate in the overall trial population was 22.9% among patients treated with Capivasertib plus Fulvestrant compared with 12.2% for patients treated with placebo plus Fulvestrant, and was 28.8% and 9.7% respectively in the biomarker altered population. Although the Overall Survival data were immature at the time of the analysis, early data are encouraging and follow up is ongoing. The most frequent Grade 3 or higher toxicities occurring in 5% or more of patients were diarrhea (9.3%) and rash (12.1%). Treatment discontinuation due to adverse events was 13% among patients who received Capivasertib plus Fulvestrant versus 2.3% among patients who received placebo plus Fulvestrant.

It was concluded that a combination of Capivasertib plus Fulvestrant is a new treatment option with significantly improved Progression Free Survival, in patients who have Hormone Receptor–positive/HER2-negative advanced breast cancer, who had progressed on, or have become resistant to endocrine therapies and CDK4/6 inhibitors.

Capivasertib in Hormone Receptor–Positive Advanced Breast Cancer. Turner N, Oliveria M, Howell SJ, et al., for the CAPItello-291 Study Group. N Engl J Med 2023; 388:2058-2070.

Osimertinib Plus Chemotherapy Superior to Osimertinib Alone in Advanced EGFR Mutated Non Small Cell Lung Cancer

RR

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 13% of all new cancers and 21% of all cancer deaths. The American Cancer Society estimates that for 2023, about 238,340 new cases of lung cancer will be diagnosed and 127,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer.

Approximately 10-15% of Caucasian patients and 35-50% of Asian patients with Adenocarcinomas, harbor activating EGFR (Epidermal Growth Factor Receptor) mutations and 90% of these mutations are either Exon 19 deletions or L858R substitution mutation in Exon 21. Approximately 25% of patients with EGFR mutated NSCLC have brain metastases at diagnosis, increasing to approximately 40% within two years of diagnosis. The presence of brain metastases often reduces median survival to less than eight months. EGFR-Tyrosine Kinase Inhibitors (TKIs) such as TARCEVA® (Erlotinib), IRESSA® (Gefitinib) and GILOTRIF® (Afatinib), have demonstrated a 60-70% response rate as monotherapy when administered as first line treatment, in patients with metastatic NSCLC, who harbor the sensitizing EGFR mutations. However, majority of these patients experience disease progression within 9-14 months. This resistance to frontline EGFR TKI therapy has been attributed to the most common, acquired T790M “gatekeeper” point mutation in EGFR, identified in 50-60% of patients.

Osimertinib (TAGRISSO®) is a highly selective third-generation, irreversible Epidermal Growth Factor Receptor TKI, presently approved by the FDA, for the first-line treatment of patients with metastatic NSCLC, whose tumors have Exon 19 deletions or Exon 21 L858R mutations, as well as treatment of patients with metastatic EGFR T790M mutation-positive NSCLC, whose disease has progressed on or after EGFR-TKI therapy. Further, Osimertinib has higher CNS penetration and is therefore able to induce responses in 70-90% of patients with brain metastases.

In the Phase III FLAURA trial, among patients with metastatic, EGFR-mutant NSCLC, first-line treatment with Osimertinib significantly improved median Overall Survival, compared with Erlotinib and Gefitinib, and Osimertinib therefore has been the preferred regimen in this patient group. The FLAURA2 trial builds on the favorable results observed in the Phase III FLAURA trial.
FLAURA2 is a randomized, open-label, multi-center, global, ongoing Phase III trial, in which 557 enrolled treatment naïve patients (N=557), with nonsquamous locally advanced (Stage IIIB-IIIC) or metastatic EGFR mutated NSCLC, were randomly assigned 1:1 to receive Osimertinib plus chemotherapy (N=279) or Osimertinib monotherapy (N=278). Patients in the combination group received Osimertinib 80 mg oral tablets once daily in combination with chemotherapy consisting of Pemetrexed 500 mg/m2 IV plus Cisplatin 75 mg/m2 IV or Carboplatin (AUC5), every three weeks for four cycles, followed by Osimertinib with Pemetrexed maintenance every three weeks. The median patient age was 62 years, approximately 62% were women and 64% were Asian. About 61% had Exon 19 deletion and 38% had L858R substitution mutation in Exon 21, 40% had CNS metastases and 53% had extrathoracic metastases. Approximately 76% of patients completed four cycles of platinum therapy. The Primary end point was investigator-assessed Progression Free Survival (PFS). Secondary endpoints included Overall Survival (OS), Objective Response Rate (ORR) and Safety. The median follow-up for progression-free survival was 19.5 months in the osimertinib–chemotherapy group and 16.5 months in the osimertinib group.

In this final analysis of the Primary endpoint of PFS, results from this study showed a significant improvement in PFS with the Osimertinib plus chemotherapy combination versus Osimertinib alone (HR=0.62; P<0.001). The median PFS was 25.5 months versus 16.7 months respectively. This represented a 38% reduction in disease progression risk, compared to Osimertinib monotherapy. The PFS benefit with Osimertinib plus chemotherapy was consistent across prespecified subgroups, including the subgroups defined according to EGFR mutation type and the presence or absence of CNS metastases at baseline. The Objective Response Rate with the combination regimen was 83%, compared to 76%, in the Osimertinib monotherapy group. The median response duration was 24 months and 15.3 months respectively. Grade 3 or higher hematologic adverse events occurred more frequently in the combination regimen group and were manageable. Data for Overall Survival were immature at the time of the analysis, and this ongoing trial will continue to assess the Secondary endpoint of Overall Survival.

The authors concluded that FLAURA2 provides compelling evidence that the addition of chemotherapy to Osimertinib in the first line treatment of nonsquamous, locally advanced or metastatic EGFR mutated NSCLC, can significantly improve outcomes, compared to Osimertinib alone, and can delay resistance to therapy and disease progression.

Osimertinib with or without Chemotherapy in EGFR-Mutated Advanced NSCLC. Planchard D, Jänne PA, Cheng Y, et al. for the FLAURA2 Investigators. N Engl J Med 2023; 389:1935-1948