Elevated White Cell Count and Risk of Thrombotic Events in Polycythemia Vera

SUMMARY: Polycythemia Vera (P. Vera) is a clonal myeloproliferative neoplasm characterized by isolated erythrocytosis in a majority of the patients, with the remaining demonstrating leukocytosis and/or thrombocytosis along with erythrocytosis. Patients usually present with this disorder in their sixth decade and are often asymptomatic, with the diagnosis made incidentally on routine laboratory evaluation. About 30% of the patients however, may initially present with a thrombotic episode, whereas a small percentage of patients may present with disease related symptoms such as pruritus and fatigue. The conventional risk factors for thrombotic events in MyeloProliferative Neoplasms (MPN) are age more than 60 years and prior thrombosis, and the presence of both these risk factors is associated with a 7-fold increased risk of thrombosis.

Overactivation of the JAK-STAT signal transduction pathway caused by V617F mutation has been implicated in majority of the patients with P. Vera. This pathway normally is responsible for passing information from outside the cell through the cell membrane to the DNA in the nucleus for gene transcription. Janus Kinase (JAK) family of tyrosine kinases are cytoplasmic proteins and include JAK1, JAK2, JAK3 and TYK2. JAK1 helps propagate the signaling of inflammatory cytokines whereas JAK2 is essential for growth and differentiation of hematopoietic stem cells. These tyrosine kinases mediate cell signaling by recruiting STATs (Signal Transducer and Activator of Transcription), with resulting modulation of gene expression. In patients with P. Vera, the aberrant myeloproliferation is the result of dysregulated JAK2-STAT signaling as well as excess production of inflammatory cytokines, associated with this abnormal signaling. JAK2 mutations such as JAK2 V617F are seen in approximately 95% of patients with P. Vera.Molecular-Mechanisms-of-MPNs

Studies have shown that JAK2 mutations that result in the overproduction of erythrocytes, leukocytes, and platelets in P. Vera also promote direct activation of leukocytes and platelets. Activated platelets and leukocytes bind to each other and activate endothelial cells, which may in turn contribute to the prothrombotic state. The prospective CYTO-PV trial published in 2011, established that maintaining hematocrit less than 45% through phlebotomies and/or cytoreductive drugs significantly decreased the risk of thrombotic events in P. Vera patients. Even though several retrospective analyses strongly suggest an association between leukocytosis and thrombosis and leukocytosis particularly at the time of the thrombotic event in P. Vera patients, no prospective trial has been conducted to assess the impact of WBC counts on thrombotic risk in P. Vera.

The REVEAL study is a large, real-world, multicenter, prospective, noninterventional, observational study, in which patients with P. Vera from US community practice and academic centers were enrolled, to evaluate the association between elevated blood counts and occurrence of thrombotic events in patients with P. Vera, using data from the REVEAL study.

This study analyzed the data of 2271 eligible patients for this analysis (78% high risk and 22% low risk). The median patient age was 66 years and 54% were male. The median disease duration was 4.1 years, 20% had a history of thrombotic events and majority of patients (53%) were receiving Hydroxyurea. Patient data was collected at diagnosis, at a 6-month period, and during follow up, 3 years from last patient enrollment, between July 2014 and August 2019 and the researchers analyzed the association between blood counts and thrombotic events. Out of 106 patients who had thrombotic events, 30 had arterial thrombotic events, most commonly, Transient Ischemic Attack and 76 had venous thrombotic events, most commonly, Deep Vein Thrombosis.

It was noted that hematocrit greater than 45% versus 45% or less (P=0.0028), WBC more than 11×109/L versus 11×109/L or less (P<0.0001), and Platelet counts more than 400×109/L versus 400×109/L or less (P=0.0170) were each associated with increased risk of thrombotic events. A WBC count of 11×109/L or more was associated with the highest thrombotic event risk compared with WBC count less than 7×109/L (P<0.0001).  When the HCT was controlled at 45% or less, an elevated WBC count (more than 12 × 109/L) was significantly associated with increased risk of thromboembolism (HR=1.95; P=0.03). In all models analyzed, advanced age and history of thrombotic events, were associated with increased thrombotic event risk.

The authors concluded that in this analysis of the largest real-world cohort of P. Vera patients to date, hematocrit more than 45%, as well as WBC more than 11×109/L and Platelet counts more than 400×109/L, were each associated with increased risk of thrombotic events. WBC more than 12×109/L was significantly associated with increased thrombotic risk, even when the HCT was controlled, suggesting that thrombotic risk may be reduced by controlling both the WBC count and HCT level. The authors added that these data support the incorporation of blood count values into risk stratification and treatment strategies for patients with P. Vera in clinical practice, and to move beyond the conventional risk model.

A Real-World Evaluation of the Association between Elevated Blood Counts and Thrombotic Events in Polycythemia Vera: An Analysis of Data from the REVEAL Study). Gerds AT, Mesa RA, Burke JM, et al. Presented at: 2022 European Hematology Association Congress; June 10, 2022; Vienna, AT. Poster # P1062.

Late Breaking Abstract – ESMO 2022: PADCEV® plus KEYTRUDA® in Previously Untreated Cisplatin-Ineligible Patients with Locally Advanced or Metastatic Urothelial Cancer

SUMMARY: The American Cancer Society estimates that in the United States for 2022, about 81,180 new cases of bladder cancer will be diagnosed and approximately 17,100 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but it is less common in women. A third of the patients initially present with locally invasive or metastatic disease. Patients with urothelial carcinoma are currently treated in the first line setting with a Platinum based chemotherapy regimen, and a checkpoint Inhibitor (PD-1 or PD-L1 inhibitor) in the second line setting. Approximately 50% of patients with advanced urothelial carcinoma are ineligible for Cisplatin-based chemotherapy. There is therefore a critical need for effective and tolerable first line treatment options in locally advanced or metastatic Urothelial Carcinoma.

Enfortumab vedotin-ejfv (PADCEV®) is an Antibody-Drug Conjugate (ADC) that targets Nectin-4, a cell adhesion molecule highly expressed in urothelial cancers and other solid tumors. Nectin-4 has been implicated in tumor cell growth and proliferation. Following binding to Nectin-4 on the cell surface, Enfortumab vedotin becomes internalized and is processed by lysosomes, with the liberation of its cytotoxic payload, Monomethyl auristatin E, which in turn disrupts microtubule assembly, leading to cell cycle arrest and apoptosis. Enfortumab vedotin resulted in significantly longer Overall Survival, Progression Free Survival, and a higher Overall Response Rate, than standard chemotherapy, in patients with locally advanced or metastatic urothelial carcinoma, who had previously received Platinum-based treatment and a PD-1 or PD-L1 inhibitor. Preclinical studies with Enfortumab vedotin have shown hallmarks of immune cell death potentially augmented by PD-1/PD-L1 inhibitors, and the rationale for this clinical trial was based on results from a previous cohort study.

Pembrolizumab (KEYTRUDA®) is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. By doing so, it unleashes the tumor-specific effector T cells, and is thereby able to undo PD-1 pathway-mediated inhibition of the immune response. Pembrolizumab is the first agent to improve Overall Survival over chemotherapy, in the second line setting, for patients with recurrent, advanced urothelial carcinoma, and a significant proportion of patients who respond, have very durable responses.

EV-103 is a clinical trial conducted to examine the safety and efficacy of Enfortumab vedotin given as monotherapy, and in combination with other anticancer therapies, as first line and second line treatment, for patients with urothelial cancer. This study was conducted in multiple parts for both locally advanced or metastatic urothelial cancer and muscle invasive bladder cancer.

EV-103/KEYNOTE-869 Cohort K is a randomized cohort investigating Enfortumab vedotin alone or in combination with Pembrolizumab as first line treatment in patients with unresectable locally advanced or metastatic urothelial cancer, who are ineligible to receive Cisplatin-based chemotherapy. In this Phase Ib/II randomized study, 149 eligible patients (N=149) were randomly assigned to receive a combination of Enfortumab vedotin 1.25 mg/kg given intravenously on days 1 and 8, and Pembrolizumab 200 mg given intravenously on day 1, every 21 days (N=76) or Enfortumab vedotin monotherapy given on the same schedule (N=73). Ineligibility for Cisplatin-based chemotherapy could be due to at least one of the following: Glomerular filtration rate (GFR) less than 60 mL/min, ECOG Performance Status of 2, Grade 2 or more hearing loss, or New York Heart Association Class III heart failure. No prior systemic treatment for locally advanced or metastatic disease, and adjuvant/neoadjuvant Platinum-based therapy within 12 months prior to randomization, were allowed. The Primary endpoint was confirmed Objective Response Rate (ORR) by BICR (Blinded Independent Central Review). Secondary endpoints included Duration of Response (DOR), Safety, Progression Free Survival (PFS) and Overall Survival (OS).

At a median follow up of 14.2 months, the confirmed Objective Response Rate was 64.5% with the Enfortumab vedotin and Pembrolizumab combination, with 10.5% of patients experiencing a Complete Response and 53.9% of patients experiencing a Partial Response. The median Duration of Response was not reached. The most common Treatment-Related Adverse Events (TRAEs) were peripheral sensory neuropathy (55.6%), fatigue (51.1%), and alopecia (48.9%).

It was concluded that in Cisplatin-ineligible patients with unresectable locally advanced or metastatic urothelial cancer, treatment with Enfortumab vedotin and Pembrolizumab combination in chemo naïve patients, resulted in high Overall Response Rate, along with a safety profile that was tolerable. The authors added that Antibody-Drug Conjugates have the potential to make a greater impact in treating bladder cancer, especially in combination with checkpoint inhibitors, as shown in this trial and these data support ongoing investigations of first line Enfortumab vedotin and Pembrolizumab in patients with locally advanced or metastatic urothelial cancer.

Study EV-103 Cohort K: Antitumor activity of enfortumab vedotin (EV) monotherapy or in combination with pembrolizumab (P) in previously untreated cisplatin-ineligible patients (pts) with locally advanced or metastatic urothelial cancer (la/mUC). Rosenberg JE, Milowsky M, Ramamurthy C, et al. Annals of Oncology (2022) 33 (suppl_7): S808-S869. 10.1016/annonc/annonc1089. LBA73

Late Breaking Abstract – ESMO 2022: Neoadjuvant KEYTRUDA® with Chemoradiation in Locally Advanced Head and Neck Squamous Cell Carcinoma

SUMMARY: The American Cancer Society estimates that in the US for 2022, about 54,000 new cases of oral cavity or oropharyngeal cancer will be diagnosed and about 11,230 patients will die of the disease. Patients with Squamous Cell Carcinoma of the head and neck, frequently present with locoregionally advanced disease.

The treatment paradigm for Head and Neck cancer has been rapidly evolving with the recognition and better understanding of immune evasion and the role of immune checkpoints or gate keepers in suppressing antitumor immunity. Blocking the immune checkpoints unleashes the T cells, resulting in T cell proliferation, activation, and a therapeutic response. Checkpoint inhibitors administered in a neoadjuvant setting activates both the priming phase of immunity within tumor tissue, and the effector phase within the tumor microenvironment. It has been shown that neoadjuvant immunotherapy expands more T-cell clones than adjuvant treatment. Preclinical models have also demonstrated that both radiation therapy and Cisplatin chemotherapy increase the PD-L1 expression on the tumor, suggesting that combining radiotherapy with anti-PD-1 therapy could improve the outcomes.

Pembrolizumab (KEYTRUDA®) is a fully humanized, Immunoglobulin G4, monoclonal antibody and checkpoint inhibitor, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the tumor-specific effector T cells. Pembrolizumab has been shown to improve Overall Survival in patients with Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

KEYNOTE-412 is a randomized, double-blind, Phase III trial, conducted to evaluate the efficacy and safety of Pembrolizumab in combination with chemoradiation versus placebo in combination with chemoradiation, in treatment naïve patients with locally advanced Head and Neck Squamous Cell carcinoma. In this study, 804 patients were randomly assigned 1:1 to receive Pembrolizumab 200 mg IV every 3 weeks plus chemoradiation (70Gy in 35 fractions along with Cisplatin 100 mg/m2 IV every 3 weeks) followed by Pembrolizumab (N=402), or placebo every 3 weeks plus chemoradiation, followed by placebo (N=402). Patients received Pembrolizumab /placebo priming dose 1 week before chemoradiation, followed by 2 doses during chemoradiation and 14 doses of maintenance therapy after chemoradiation, for a total of 17 doses. Enrolled patients had newly diagnosed, pathologically proven, treatment naive locally advanced Head and Neck Squamous Cell carcinoma (T3-T4, N0-N3 or any N2a-3, T1-T4 larynx/hypopharynx/oral cavity/p16-negative oropharynx cancers, or T4 or N3 p16-positive oropharynx cancer). Both treatment groups were well balanced. The Primary endpoint was Event Free Survival (EFS). Secondary endpoints included Overall Survival (OS), and Safety.

At the time of data cutoff, with a median follow up of 47.7 months, there was a favorable trend toward improved Event Free Survival (EFS) with the addition of Pembrolizumab vs placebo to chemoradiation (HR 0.83, P=0.04), but the difference did not achieve statistical significance. The 2-year EFS was 63.2% in the Pembrolizumab group and 56.2% in the placebo group. In an exploratory analysis however, the 2-year EFS among patients with high expression of PD-L1 (CPS 20 or higher) was 71% in the Pembrolizumab group and 62% in the placebo group. A favorable of Overall Survival benefit was also observed among these patients, with a 3-year OS of 79% in Pembrolizumab group and 73% in the placebo group.

It was concluded that Pembrolizumab in combination with chemoradiation was associated with a favorable trend toward improved Event Free Survival, compared with placebo plus chemoradiation, in patients with locally advanced Head and Neck Squamous Cell carcinoma, but the difference did not reach statistical significance. The researchers added that perhaps patients with high CPS score on the tumor could benefit with this treatment approach.

Primary results of the phase III KEYNOTE-412 study: Pembrolizumab (pembro) with chemoradiation therapy (CRT) vs placebo plus CRT for locally advanced (LA) head and neck squamous cell carcinoma (HNSCC). Machiels J, Tao Y, Burtness B, et al. Annals of Oncology (2022) 33 (suppl_7): S808-S869. 10.1016/annonc/annonc1089. LBA5

Late Breaking Abstract – ESMO 2022: Abemaciclib plus Transtuzumab versus Chemotherapy in HR-positive, HER2-positive Advanced Breast Cancer

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. Approximately 290,560 new cases of breast cancer will be diagnosed in 2022 and about 43,780 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is a heterogeneous disease and approximately 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors. The most common subtype of metastatic breast cancer is Hormone Receptor-positive (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. Human Epidermal growth factor Receptor 2 (HER2) overexpression is reported in about 15%-20% of primary breast carcinomas and is associated with poor prognosis, and nearly half of HER2-positive breast cancers are also HR-positive. Patients with HER2-positive breast cancers are generally treated with HER2-targeted therapy combined with chemotherapy. Patients with HER2-positive and HR-positive breast cancer are additionally treated with long-term hormone therapy.

Cyclin Dependent Kinases (CDKs) play a very important role to facilitate orderly and controlled progression of the cell cycle. Genetic alterations in these kinases and their regulatory proteins have been implicated in various malignancies. VERZENIO® (Abemaciclib) is an oral, selective inhibitor of CDK4 and CDK6 kinase activity, and prevents the phosphorylation and subsequent inactivation of the Rb tumor suppressor protein, thereby inducing G1 cell cycle arrest and inhibition of cell proliferation. HERCEPTIN® (Trastuzumab) is a humanized monoclonal antibody targeting HER2 oncogene. FASLODEX® (Fulvestrant) is a parenteral, Selective Estrogen Receptor Degrader (SERD) and is approved for the treatment of postmenopausal women with HR-positive metastatic breast cancer.

monarcHER (NCT02675231) is an International, randomized, multicenter, open-label, three-group, Phase 2 trial, conducted to compare the efficacy of Abemaciclib plus Trastuzumab with or without Fulvestrant, with standard-of-care chemotherapy of physician’s choice plus trastuzumab, in women with advanced breast cancer. In this study, 237 patients were enrolled. Eligible patients had Hormone Receptor (HR)-positive, HER2-positive advanced breast cancer, with unresectable, locally advanced, recurrent, or metastatic disease, and had previously received at least two HER2-targeted therapies for advanced disease. Patients were randomly assigned 1:1:1 to Group A (Abemaciclib, Trastuzumab, and Fulvestrant) N=79, Group B (Abemaciclib and Trastuzumab) N=79, or Group C (standard-of-care chemotherapy and trastuzumab) N=79. Treatment consisted of Abemaciclib 150 mg orally twice daily on days 1-21 of a 21-day cycle, Trastuzumab 8 mg/kg IV on cycle 1, day 1, followed by 6 mg/kg IV on day 1 of each subsequent 21-day cycle, and Fulvestrant 500 mg IM on days 1, 15, and 29 and once every 4 weeks thereafter. Standard-of-care chemotherapy was administered as specified by the product label. Patients were stratified by number of previous systemic therapies for advanced breast cancer and measurable versus non-measurable disease. An exploratory biomarker analysis of breast cancer molecular subtypes was conducted by RNA sequencing. The Primary endpoint was investigator-assessed Progression Free Survival (PFS), first testing Group A versus Group C, and if this result was significant, then Group B versus Group C. Secondary end points included Overall Survival (OS), Overall Response Rate, Patient Reported Outcomes, and pharmacokinetics. Safety was assessed in all patients who had received at least one dose of study treatment.

Previous analyses from this trial revealed that after a median follow up of 19.0 months, the Primary endpoint was met, with significantly superior PFS in Group A compared to Group C (8.3 months versus 5.7 months, respectively, HR=0.67; P=0.051), with a reduction in the risk for disease progression or death of 33%. (Lancet Oncol. 2020;21:763–775). The researchers herein reported the results, after a median follow up of 52.9 months.

The median Overall Survival was 31.1 months in Group A, 29.2 months in Group B and 20.7 months in Group C. When Group A was compared with Group C, the triplet regimen with Abemaciclib, Trastuzumab, and Fulvestrant (Group A) induced a statistically significant improvement in Overall Survival, compared with Trastuzumab plus chemotherapy (Group C). There was a numerically improved Overall Survival benefit with Abemaciclib, in combination with HER2-targeted therapy (Trastuzumab) with or without hormonal therapy (Fulvestrant), compared with chemotherapy plus Trastuzumab, and there was a consistent benefit observed with the addition of Abemaciclib across all pre-specified subgroups. Updated Progression Free Survival and safety findings were consistent with the primary analysis. An exploratory biomarker analysis by RNA sequencing suggested that Luminal subtypes were associated with longer Progression Free Survival (8.6 versus 5.4 months, HR=0.54) and Overall Survival (31.7 versus 19.7 months, HR=0.68), compared to non-Luminal subtypes. The most common serious adverse events in Group A were pyrexia, diarrhea, urinary tract infection, and acute kidney injury (3% each); in Group B were diarrhea and pneumonitis (3% each); and in Group C were neutropenia (6%) and pleural effusion (3%).

The authors concluded that based on this final analysis, a triple-agent, chemotherapy-free treatment regimen consisting of Abemaciclib plus Trastuzumab, with or without Fulvestrant, numerically improved Overall Survival in women with Hormone Receptor-positive, HER2-positive, advanced breast cancer, compared to chemotherapy plus Trastuzumab.

Final overall survival (OS) for abemaciclib plus trastuzumab +/- fulvestrant versus trastuzumab plus chemotherapy in patients with HR+, HER2+ advanced breast cancer (monarcHER): A randomized, open-label, phase II trial. Andre F, Nadal JC, Denys H, et al. Annals of Oncology (2022) 33 (suppl_7): S808-S869. 10.1016/annonc/annonc1089. LBA18

Late Breaking Abstract – ESMO 2022: CABOMETYX®, OPDIVO® and YERVOY® in Previously Untreated Advanced Renal Cell Carcinoma

SUMMARY: The American Cancer Society estimates that 79,000 new cases of kidney cancers will be diagnosed in the United States in 2022 and about 13,920 people will die from this disease. Clear Cell Renal Cell Carcinoma (RCC) is by far the most common type of kidney cancer in adults. Modifiable risk factors include smoking, obesity, workplace exposure to certain substances and high blood pressure. The five-year survival of patients with advanced RCC is about 14% and there is a significant unmet need for improved therapies for this disease.

OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, whereas YERVOY® (Ipilimumab) is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152). Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation, and a therapeutic response. The FDA in 2018, granted approvals to OPDIVO® and YERVOY® in combination, for the treatment of Intermediate or Poor-risk, previously untreated advanced Renal Cell Carcinoma.

CABOMETYX® (Cabozantinib) is an oral, small-molecule Tyrosine Kinase Inhibitor (TKI), which targets Vascular Endothelial Growth Factor Receptors (VEGFR), as well as tyrosine kinases MET and AXL. Both MET and AXL are upregulated in Renal Cell Carcinoma as a consequence of VHL inactivation, and increased expression of MET and AXL is associated with tumor progression and development of resistance to VEGFR inhibitors. Further, CABOMETYX® promotes an immune-permissive environment, which may enhance response to checkpoint inhibitors. CABOMETYX® was approved by the FDA in 2016 for the treatment of advanced Renal Cell Carcinoma.

COSMIC-313 is a global, multicenter, randomized, double-blinded, controlled, ongoing Phase III pivotal trial, conducted to evaluate the triplet combination of Cabozantinib, Nivolumab and Ipilimumab versus the doublet combination of Nivolumab and Ipilimumab, in patients with previously untreated advanced Intermediate or Poor-risk Renal Cell Carcinoma. COSMIC-313 was designed to answer whether adding Cabozantinib to dual checkpoint inhibition can improve outcomes among patients with Intermediate and Poor-risk advanced Renal Cell Carcinoma.

In this trial, 855 treatment naïve, advanced clear cell Renal Cell Carcinoma patients of IMDC (International Metastatic RCC Database Consortium) Intermediate or Poor risk were randomized 1:1 to receive Cabozantinib plus Nivolumab and Ipilimumab (N=428) or placebo plus Nivolumab and Ipilimumab (N=427). Patients in the study group received Cabozantinib 40 mg, orally once daily in combination with Nivolumab 3 mg/kg IV and Ipilimumab 1 mg/kg IV once every 3 weeks for 4 doses total followed by Cabozantinib 40 mg orally once daily and Nivolumab 480 mg/kg flat dose IV, once every 4 weeks for up to 2 years. Patients in the control group received the same regimen, but instead of Cabozantinib, received a matched placebo. Both treatment groups were well balanced. The median patient age was 60 years, 75% were men, 63% had PD-L1 expression of less than 1%, 75% had Intermediate-risk disease, 25% were Poor risk, and 65% had prior nephrectomy. The Primary endpoint was Progression Free Survival (PFS), as assessed by Blinded Independent Radiology Committee (BIRC). Secondary endpoints included Overall Survival (OS), Objective Response Rate (ORR) and Safety. The median follow up was 20.2 months.

The study met the Primary endpoint and the median PFS was not reached in the Cabozantinib group and was 11.3 months in the placebo group (HR=0.73; P=0.013). Patients treated with the Cabozantinib three-drug combination had a 27% lower risk of disease progression or death compared to those on the two drug immunotherapy combination. This PFS benefit was predominantly noted in the Intermediate-risk group. The Objective Response Rate was 43% with the Cabozantinib combination versus 36% in the placebo plus dual immunotherapy group, with 3% of patients achieving a Complete Response in both treatment groups. The Disease Control Rate was 86% and 72%, respectively. The median Duration of Response was not reached in either treatment group. Grade 3/4 adverse events occurred in 73% of patients treated with the combination of Cabozantinib, Nivolumab and Ipilimumab, and in 41% of patients treated with the Nivolumab and Ipilimumab combination. Discontinuation of all treatment agents due to adverse events occurred in 12% and 5% of patients, respectively.

The authors concluded that this is the first study to show that a TKI added to dual checkpoint inhibition significantly improved Progression Free Survival, in patients with untreated, Intermediate or Poor risk advanced kidney cancer, compared to doublet immunotherapy. Follow-up for Overall Survival is ongoing.

Phase III study of cabozantinib (C) in combination with nivolumab (N) and ipilimumab (I) in previously untreated advanced renal cell carcinoma (aRCC) of IMDC intermediate or poor risk (COSMIC-313). Choueiri TK, Powles TB, Albiges L, et al. Annals of Oncology (2022) 33 (suppl_7): S808-S869. 10.1016/annonc/annonc1089. LBA8

Late Breaking Abstract – ESMO 2022: Apalutamide Plus Androgen Deprivation Therapy in Biochemically Relapsed Prostate Cancer

SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 268,490 new cases of prostate cancer will be diagnosed in 2022, and 34,500 men will die of the disease. The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer and is the first treatment intervention.

The major source of PSA (Prostate Specific Antigen) is the prostate gland, and the PSA levels are therefore undetectable within 6 weeks after Radical Prostatectomy. Similarly, following Radiation Therapy there is a gradual decline in PSA, before reaching a post treatment nadir. A detectable PSA level after Radical Prostatectomy, or a rising PSA level following Radiation Therapy, is considered PSA failure or biochemical recurrence. Approximately 35% of the patients with prostate cancer will experience PSA only relapse within 10 years of their primary treatment and a third of these patients will develop documented metastatic disease within 8 years following PSA only relapse. Rising PSA is therefore a sign of recurrent disease. Patient’s with biochemically relapsed prostate cancer following local therapy, and a short PSA doubling time, are at risk for distant metastases.

ERLEADA® (Apalutamide) is an orally administered Androgen Receptor (AR) inhibitor that binds directly to the ligand-binding domain of the AR. Apalutamide inhibits AR nuclear translocation, inhibits DNA binding, and impedes AR-mediated transcription. Apalutamide is presently approved for the treatment of patients with metastatic Castration Sensitive Prostate Cancer and non-metastatic Castration Resistant Prostate Cancer. ZYTIGA® (Abiraterone) is a selective, irreversible inhibitor of CYP 17A1 enzyme and decreases androgen biosynthesis in the testes, adrenal glands, and prostate-tumor tissue. Both Apalutamide and Abiraterone plus prednisone have been shown to prolong Overall Survival in the metastatic prostate cancer.

The purpose of this study was to evaluate if intensification of Androgen Deprivation Therapy (ADT) prolongs biochemical Progression Free Survival (PFS), in patients with biochemically relapsed prostate cancer. PRESTO is a randomized, open-label Phase III trial, in which 504 prostate cancer patients who had radical prostatectomy were included. Study patients had biochemical recurrence (PSA more than 0.05 ng/mL), a PSA doubling time of 9 months or less, and without distant metastases on conventional imaging (CT and Bone scan). Patients were randomized 1:1:1 to receive a finite 52-week treatment course with ADT alone (N=167), ADT plus Apalutamide (N=168), or ADT plus Apalutamide plus Abiraterone/Prednisone (N=169). Patients were stratified by PSA doubling time (less than 3 months versus 3-9 months) and patients were followed up following treatment completion with mostly lab assessment until PSA progression, at which point, treatment was per investigator discretion. Patient and disease characteristics at baseline were well balanced among the 3 study groups. The median age was 67 years and 84% of patients were white. The median PSA at baseline was 1.77 ng/mL. The PSA doubling time was less than 3 months for 26% of patients and between 3 and 9 months for 74% of patients. The median time between radical prostatectomy and baseline was 4.4 years. Overall, 85% of patients had prior radiation and 42% of patients had prior ADT. The Primary endpoint of the study was to compare biochemical Progression Free Survival (defined as increase in serum PSA of more than 0.2 ng/mL following treatment) in each experimental group with ADT alone. Secondary endpoints included safety, patient-reported Quality of Life (QOL), time to testosterone recovery (more than 50 ng/dL following treatment completion), Metastasis-Free Survival, and time to castration resistance.

The first planned interim analysis at a median follow-up of 21.5 months showed that both study groups significantly prolonged biochemical PFS compared to the control group. The median biochemical (PSA) PFS was 24.9 months with Apalutamide plus ADT versus 20.3 months with ADT alone (HR=0.52; P=0.00047). The median biochemical PFS was 26.0 months with ADT plus Apalutamide plus Abiraterone/Prednisone versus 20.0 months with ADT alone (HR=0.48; P=0.00008). A preplanned subgroup analysis based on stratification by PSA doubling time showed a consistent benefit in both study groups, compared to the control group, regardless of the length of PSA doubling time. The median time to testosterone recovery following treatment completion was 3.9 months with ADT alone, 3.8 months with Apalutamide plus ADT and 4.7 months with ADT plus Apalutamide plus Abiraterone/Prednisone. There was an increase in the incidence of adverse events with the addition of Abiraterone.

It was concluded that intensifying Androgen Receptor blockade with Apalutamide plus Androgen Deprivation Therapy prolongs biochemical PFS with a manageable safety profile and without impacting time to testosterone recovery, following a finite duration of treatment. The authors added that intensification of Androgen Receptor blockade should be considered in high-risk biochemically relapsed prostate cancer.

LBA63 – PRESTO: A phase III, open-label study of androgen annihilation in patients (pts) with high-risk biochemically relapsed prostate cancer (AFT-19). Aggarwal R, Heller G, Hillman D, et al. Annals of Oncology (2022) 33 (suppl_7): S808-S869. 10.1016/annonc/annonc1089

Late Breaking Abstract – ASCO 2022: Landmark Five Year Overall Survival Rates for OPDIVO® and YERVOY® Combination in NSCLC

SUMMARY: The American Cancer Society estimates that for 2022, about 236,740 new cases of lung cancer will be diagnosed and 135,360 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.

Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions by switching off the immune system T cells. Immune checkpoint proteins/receptors include CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152) and PD-1(Programmed cell Death 1). Checkpoint inhibitors unleash the T cells resulting in T cell proliferation, activation, and a therapeutic response. OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the T cells. YERVOY® is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4.

CheckMate-227 is an open-label, multi-part, global, Phase III trial in which OPDIVO® based regimens were compared with Platinum-doublet chemotherapy in patients with first line advanced NSCLC, across non-squamous and squamous tumor histologies. This study consisted of Part 1a/Part 1b and Part 2. In Part 2 of this trial, OPDIVO® plus chemotherapy was compared with chemotherapy alone, regardless of PD-L1 expression. Part 2 did not meet its Primary endpoint for Overall Survival for OPDIVO® plus chemotherapy versus chemotherapy alone, in patients with non-squamous NSCLC, and is published elsewhere.

Part 1a: Patients received OPDIVO® 3 mg/kg IV every 2 weeks plus YERVOY® 1 mg/kg IV every 6 weeks (N=396), OPDIVO® monotherapy 240 mg IV every 2 weeks (N=396) or chemotherapy alone given every 3 weeks for up to four cycles (N=397), in patients whose tumors had PD-L1 expression of 1% or more.
Part 1b: Patients received OPDIVO® plus YERVOY® (N=187), OPDIVO® 360 mg IV every 3 weeks plus chemotherapy IV every 3 weeks for up to four cycles (N=177), or chemotherapy alone IV every 3 weeks for up to four cycles (N=186), in patients whose tumors did not express PD-L1 (less than 1%)

Patients were stratified by histology, and treatment was administered until disease progression, unacceptable toxicity, or administered for 2 years for immunotherapy. It should be noted that when this trial was launched, chemotherapy along with immunotherapy or immunotherapy alone was not approved for the front-line treatment of NSCLC. Therefore, dual immunotherapy combination was not compared with current standards of care such as chemotherapy plus immunotherapy.

There were two independent Primary endpoints in Part 1 for OPDIVO® plus YERVOY® versus chemotherapy: Overall survival (OS) in patients whose tumors express PD-L1 (assessed in patients enrolled in Part 1a) and Progression Free Survival (PFS) in patients with TMB of 10 mut/Mb or more, across the PD-L1 spectrum (assessed in patients enrolled across Part 1a and Part 1b). Other assessments included Objective Response Rate (ORR), Duration of Response (DOR), and treatment-free interval. Treatment-free interval was measured in patients who discontinued study therapy and was defined as the time from last study dose to start of subsequent systemic therapy.

The Overall Survival (OS) data was previously reported at a minimum follow up of 29 months, and the median OS was of 17.1 months for the OPDIVO® plus YERVOY® group, compared to 14.9 months in the chemotherapy group (HR=0.79; P=0.007), with a 2-year OS rate of 40.0% and 32.8%, respectively. The researchers here in presented data after a minimum follow up of 61.3 months (5 years).

Patients whose tumors had PD-L1 expression of 1% or more continued to have sustained long term OS benefit with OPDIVO® plus YERVOY® when compared to chemotherapy (HR=0.77), and the 5-year OS rates were 24% with OPDIVO® plus YERVOY® compared to 14% with chemotherapy alone.

Patients with a PD-L1 expression of less than 1% also demonstrated continued long term OS benefit with OPDIVO® plus YERVOY® when compared to chemotherapy (HR = 0.65), and the 5-year OS rates were 19% for OPDIVO® plus YERVOY&reg compared to 7% for chemotherapy alone.

Among patients who survived for 5 years, median PFS was 59.1 months for PD-L1–positive patients and 60.7 months for PD-L1–negative patients who received OPDIVO® plus YERVOY®, compared to 9.5 months and 24.9 months respectively, for those who received chemotherapy.

Among those who responded to treatment, more patients who received OPDIVO® plus YERVOY® remained in response at five years, compared to chemotherapy, in both PD-L1 expression of 1% or more group (28% versus 3%) and PD-L1 expression of less than 1% group (21% versus 0%), respectively.

Among patients treated with OPDIVO® plus YERVOY® who were alive at five years, approximately two-thirds of patients did not receive any subsequent therapy for more than three years after stopping treatment, regardless of PD-L1 expression.

It was concluded that in this longest reported follow up of a Phase III trial of first line, chemotherapy free, combination immunotherapy, in metastatic Non Small cell Lung Cancer, a combination of OPDIVO® plus YERVOY® continued to provide long term durable clinical benefit and increased 5-year survivorship, when compared to chemotherapy, in previously untreated patients with metastatic NSCLC, regardless of PD-L1 expression.

Five-year survival outcomes with nivolumab (NIVO) plus ipilimumab (IPI) versus chemotherapy (chemo) as first-line (1L) treatment for metastatic non–small cell lung cancer (NSCLC): Results from CheckMate 227. Brahmer JR, Lee J-S, Ciuleanu T-E, et al. J Clin Oncol. 2022;40(suppl 17):LBA9025. doi:10.1200/JCO.2022.40.17_suppl.LBA9025

Late Breaking Abstract – ASCO 2022: Docetaxel as Radiosensitizer Improves Overall Survival in Cisplatin-Ineligible Head and Neck cancer

SUMMARY: The American Cancer Society estimates that in the US for 2022, about 54,000 new cases of oral cavity or oropharyngeal cancer will be diagnosed and about 11,230 patients will die of the disease. Patients with squamous cell carcinoma of the head and neck, frequently present with locoregionally advanced disease. For patients in this setting, chemoradiotherapy is an effective non-surgical approach as primary treatment. Alternatively, chemoradiotherapy can be delivered as adjuvant therapy after a curative resection.

Cisplatin-based concurrent chemoradiation is generally accepted as the standard, definitive non-surgical and post-operative approach in selected patients with locoregionally advanced squamous cell carcinoma of the head and neck. This treatment can however be associated with substantial morbidity and lifelong toxicities. Cetuximab is an immunoglobulin G1 chimeric monoclonal antibody against Epidermal Growth Factor Receptor (EGFR), and the only approved targeted agent in locoregionally advanced squamous cell carcinoma of the head and neck. Cetuximab plus Radiotherapy significantly improved Overall Survival at 5 years, when compared with radiotherapy alone, in patients with locoregionally advanced squamous cell carcinoma of the head and neck (Lancet Oncol. 2010). Cetuximab plus Radiotherapy is therefore an important treatment option in this patient group. However, financial barriers make Cetuximab as a Cisplatin substitute, inaccessible to patients, in low and middle-income countries.

Docetaxel is a semisynthetic taxane that affects polymerized tubulin to promote microtubule formation and inhibit its disassembly. Docetaxel has been shown to have significant antitumor activity as a single agent in head and neck cancer, when given in the neoadjuvant setting. Docetaxel is also a potent radiosensitizer. The researchers evaluated Docetaxel as a radiosensitizer in this clinical trial.

The authors in this open-label, randomized, Phase III study enrolled 356 Cisplatin-ineligible patients with locally advanced head and neck squamous cell carcinoma, planned for treatment with radical or adjuvant chemoradiation. The patients were randomly assigned 1:1 to receive Radiation alone (N=176) or Radiation with concurrent Docetaxel 15 mg/m2 IV weekly for a maximum of 7 cycles (N=180). Both treatment groups were well balanced. The median age was 62 yrs, approximately 45% of patients had a ECOG Performance Status of 2, and reasons for Cisplatin ineligibility included low creatinine clearance (26%), and hearing loss (43%). Approximately 33% of patients had oral cavity cancer and about two-thirds of patients had Stage IVA disease. The FACT-G, and Head and Neck questionnaires were completed by patients at baseline, 6 months, 12 months and at 24 months. FACT-G (Functional Assessment of Cancer Therapy-G) is a 27-item questionnaire designed to measure four domains of Health-Related Quality of Life (HRQOL) in cancer patients, which includes physical, social, emotional, and functional well-being. The Primary endpoint was Disease Free Survival (DFS), and key Secondary endpoints included Overall Survival (OS), adverse events and Quality of Life.

It was noted that the 2-year DFS was 30.3% with Radiation alone versus 42% with Docetaxel plus Radiation Therapy (HR=0.67; P=0.002). Docetaxel plus Radiation Therapy also significantly improved Overall Survival. The median Overall Survival was 15.3 months with Radiation Therapy alone, versus 25.5 months in the Docetaxel plus Radiation Therapy group (P=0.035). The 2 -year Overall Survival was also significantly higher in the Docetaxel plus Radiation Therapy group and was 41.7% with Radiation Therapy alone, versus 50.8% in the Docetaxel plus Radiation Therapy group (HR=0.74; P=0.035). These survival outcomes were observed across all preplanned subgroups.

Grade 3 or above adverse events were seen in 58% of patients receiving Radiation Therapy alone and in 81.6% of patients receiving Docetaxel plus Radiation Therapy. The addition of Docetaxel to Radiation Therapy resulted in a higher incidence of Grade 3 and above mucositis (49.7% versus 22.2%; P<0.001), odynophagia (52.5% versus 33.5%; P<0.001) and dysphagia (49.7% versus 33%; P<0.002). The addition of Docetaxel however did not lead to a worsening of Quality of Life, including Trial Outcome Index and FACT-G scores at 6 months.

The authors concluded that the addition of Docetaxel to Radiation Therapy improved Disease Free Survival and Overall Survival, in Cisplatin-ineligible locally advanced head and neck squamous cell carcinoma, and provides an evidence based, financially more viable treatment option, for this patient group.

Results of phase 3 randomized trial for use of docetaxel as a radiosensitizer in patients with head and neck cancer unsuitable for cisplatin-based chemoradiation. Patil VM, Noronha V, Menon NS, et al. DOI: 10.1200/JCO.2022.40.17_suppl.LBA6003 Journal of Clinical Oncology 40, no. 17_suppl (June 10, 2022) LBA6003.

Late Breaking Abstract – ASCO 2022: Improved Distant Metastasis-Free Survival with Adjuvant KEYTRUDA® in High Risk Stage II Melanoma

SUMMARY: The American Cancer Society’s estimates that for 2022, about 99,780 new cases of melanoma of the skin will be diagnosed in the United States and 7,650 people are expected to die of the disease. The rates of melanoma have been rising rapidly over the past few decades, but this has varied by age. Surgical resection with a curative intent is the standard of care for patients with early stage melanoma, with a 5-year survival rate of 98% for Stage I disease and 90% for Stage II disease. The current standard of care for patients following resection of high-risk Stage II disease is observation, even though patients with Stage IIB and IIC disease presenting with high-risk features (depth of invasion, T-category, ulceration) have 5 and 10 year melanoma-specific survival similar to that of patients with Stage IIIA and IIIB disease.

KEYTRUDA® (Pembrolizumab) is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. By doing so, it unleashes the tumor-specific effector T cells, and is thereby able to undo PD-1 pathway-mediated inhibition of the immune response. The FDA in 2019, approved KEYTRUDA® for the adjuvant treatment of patients with melanoma, with involvement of lymph node(s), following complete resection (Stage III). The present study was conducted to evaluate the role of adjuvant immunotherapy in patients with high risk Stage II melanoma.

KEYNOTE-716 is a randomized, double-blind, Phase III trial, in which 976 patients aged 12 years or older, with completely resected cutaneous Stage IIB or IIC melanoma, and no lymph node involvement, were randomly assigned 1:1 to receive KEYTRUDA® 200 mg IV (2 mg/kg for pediatric patients) or placebo, every 3 weeks for 17 cycles (up to 1 year). Patients were stratified by T category 3b, 4a, 4b (adults) and with a separate stratum for pediatric patients. Approximately 65% had Stage IIB disease and 35% had Stage IIC disease. There was no prespecified analysis for PD-L1 or BRAF status in this study, as there was inconsistent and small amounts of tissue available for testing. This was the first part (Part 1) of this double-blind study. The Primary endpoint was Relapse Free Survival (RFS) per investigator assessment, and Safety. The second part (Part 2) of this study was open-label design, and adults and pediatric patients were eligible to receive up to 35 additional cycles of treatment, only if they had recurrence after receiving the placebo or completed 17 cycles of KEYTRUDA®. Patients in the KEYTRUDA® group who experienced disease recurrence within 6 months of completing the treatment were excluded from Part 2 of the study. Secondary end points included Distant Metastasis Free Survival (DMFS), Overall Survival (OS) and Quality of Life.

At median follow up of 14.4 months, adjuvant KEYTRUDA® significantly prolonged RFS compared to placebo (HR=0.65; P=0.00658), in patients with resected Stage IIB or IIC melanoma. At the time of this analysis, 11.1% of patients on KEYTRUDA® had a recurrence, compared to 16.8% of those receiving placebo. The 12-month RFS rate was 90.5% for KEYTRUDA® versus 83.1% for placebo.

The researchers herein presented new data from the analysis of Distant Metastasis-Free Survival (DMFS) and Recurrence Free Survival (RFS), with a longer median follow up of 26.9 months. Adjuvant KEYTRUDA® significantly improved DMFS when compared to placebo (HR=0.64; P=0.0029), representing a 36% reduction in the risk of recurrence. The 24-month DMFS rate was 88.1% versus 82.2%, respectively. Grade 3 or more Adverse Events occurred in 28.4% of patients in the KEYTRUDA® group, versus 20% in the placebo group. Hypothyroidism was the most common immune mediated Adverse Event with KEYTRUDA®, compared to placebo (17.2% versus 3.7%).

The authors concluded that adjuvant KEYTRUDA® for resected Stage IIB and IIC melanoma, significantly improved Distant Metastasis-Free Survival, with continued reduction in the risk of recurrence, and a favorable benefit-risk profile. KEYNOTE-716 is the first randomized Phase III trial of an anti-PD-1 therapy in resected Stage II melanoma, and these findings represent an important milestone for this patient group.

Distant metastasis-free survival with pembrolizumab versus placebo as adjuvant therapy in stage IIB or IIC melanoma: The phase 3 KEYNOTE-716 study. Long GV, Luke JJ, Khattak M, et al. DOI: 10.1200/JCO.2022.40.17_suppl.LBA9500 Journal of Clinical Oncology 40, no. 17_suppl (June 10, 2022) LBA9500-LBA9500.

Late Breaking Abstract – ASCO 2022: RUBRACA® Monotherapy as Maintenance Treatment in Newly Diagnosed Ovarian Cancer

SUMMARY: It is estimated that in the United States, approximately 19,880 women will be diagnosed with ovarian cancer in 2022 and 12,810 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. Approximately 85% of all ovarian cancers are epithelial in origin, and approximately 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 rate of about 20-30%.

DNA damage is a common occurrence in daily life by UV light, ionizing radiation, replication errors, chemical agents, etc. This can result in single and double strand breaks in the DNA structure which must be repaired for cell survival. The two vital pathways for DNA repair in a normal cell are BRCA1/BRCA2 and PARP. BRCA1 and BRCA2 are tumor suppressor genes and they recognize and repair double strand DNA breaks via Homologous Recombination (HR) pathway. Homologous Recombination is a DNA repair pathway utilized by cells to accurately repair DNA double-stranded breaks during the S and G2 phases of the cell cycle, and thereby maintain genomic integrity.

Homologous Recombination Deficiency (HRD) is noted following mutation of genes involved in HR repair pathway. At least 15 genes are involved in the Homologous Recombination Repair (HRR) pathway including BRCA1 and BRCA2 genes. Mutations in BRCA1 and BRCA2 account for about 20-25% of hereditary breast cancers 15% of ovarian cancers, in addition to other cancers such as colon and prostate. BRCA mutations can either be inherited (Germline) and present in all individual cells or can be acquired and occur exclusively in the tumor cells (Somatic).

The PARP (Poly ADP Ribose Polymerase) family of enzymes includes PARP1 and PARP2, and is a related enzymatic pathway that repairs single strand breaks in DNA. In a BRCA mutant, the cancer cell relies solely on PARP pathway for DNA repair to survive. PARP inhibitors traps PARP onto DNA at sites of single-strand breaks, thereby preventing their repair and generate double-strand breaks. These breaks cannot be repaired accurately in tumors harboring defects in Homologous Recombination Repair pathway genes, such as BRCA1 or BRCA2 mutations, and this leads to cumulative DNA damage and tumor cell death.

RUBRACA® is an oral, small molecule PARP inhibitor, developed for treatment of ovarian cancer associated with Homologous Recombination DNA repair deficiency (HRD). With regards to ovarian cancer, RUBRACA® is presently approved by the FDA for the maintenance treatment of patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer, who are in a Complete or Partial Response to platinum-based chemotherapy.

ATHENA is an international, multicenter, randomized, double-blind, placebo-controlled, Phase III trial, which evaluated first-line maintenance treatment for patients with newly diagnosed advanced ovarian cancer. ATHENA was designed to evaluate RUBRACA® first-line maintenance treatment in a broad group of patients, including those without BRCA1 or BRCA2 (BRCA) mutations or other evidence of Homologous Recombination Deficiency (HRD), or high-risk clinical characteristics such as residual disease. ATHENA study has two separate and fully independently powered comparisons evaluating RUBRACA® monotherapy (ATHENA–MONO) and RUBRACA® plus Nivolumab (ATHENA–COMBO), as maintenance treatment in this patient population. The authors herein reported the efficacy and safety results from the ATHENA–MONO comparison of RUBRACA® maintenance treatment versus placebo.

In the ATHENA-MONO trial, patients with Stage III-IV high-grade ovarian cancer undergoing surgical cytoreduction (R0/complete resection permitted) and responding to 4-8 cycles of first-line platinum-doublet chemotherapy, were randomly assigned 4:1 to receive RUBRACA® 600 mg orally twice daily (N=427) or placebo. Treatment was continued for 24 months or until disease progression or unacceptable toxicity. Patients were stratified by HRD test status, residual disease after chemotherapy, and timing of surgery (primary surgery versus interval debulking). The median age was 61 years, majority of the patients (78%) did not have a BRCA mutation. Patients were stratified by HRD classification (BRCA wild-type/LOH (Loss of Heterozygosity) high-16% or more, BRCA wild-type/LOH low-less than 16%, and BRCA wild-type/LOH indeterminate). The Primary end point of investigator-assessed Progression Free Survival (PFS) was assessed in a step-down procedure, first in the HRD population (BRCA-mutant or BRCA wild-type/LOH high tumor), and then in the Intent-To-Treat (ITT) population. Secondary end points included Overall Survival (OS), investigator-assessed Objective Response Rate (ORR) in patients with measurable disease at baseline and Duration of Response (DOR) for patients with investigator-assessed confirmed radiographic Complete Response (CR) or Partial Response (PR). The median duration of follow was 26 months.

The median PFS in the HRD population was 28.7 months with RUBRACA® maintenance group compared to 11.3 months with placebo (HR=0.47; P=0.0004). In the Intent to Treat (ITT) population, the median PFS was 20.2 months in the RUBRACA® group versus 9.2 months in the placebo group (HR=0.52; P<0.0001). At 24 months, 45% of RUBRACA®-treated patients in the ITT population were progression-free compared with 25.4% with placebo. In the HRD negative population, the median PFS was 12.1 months in the RUBRACA® group versus 9.1 months in the placebo group (HR=0.65). Exploratory subgroup analyses of PFS in the ITT population showed that there was greater clinical benefit with RUBRACA® compared to placebo among all subgroups, including BRCA-mutant, BRCA wild-type/LOH high, and BRCA wild-type/LOH low (HRD-negative).

Among RUBRACA®-treated patients with measurable disease at baseline, the ORR, was 58.8% in the HRD population and 48.8% in the ITT population. Among the placebo-treated patients, the ORR was 20% in the HRD population and 9.1% in the ITT population. The median Duration of Response in the HRD and ITT populations for RUBRACA®-treated responders versus the placebo-treated responders respectively, was 16.7 months versus 5.5 months and 22.1 months versus 5.5 months. The Overall Survival results were immature at the time of the data cutoff. The most common Grade 3 or more adverse events in the RUBRACA® group were anemia (29%) and neutropenia 15%).

The authors concluded that in the ATHENA-MONO trial, RUBRACA® monotherapy is an effective first-line maintenance option that provides clinical benefit to a broad population of patients with newly diagnosed ovarian cancer, regardless of BRCA mutation and HRD status.

A Randomized, Phase III Trial to Evaluate Rucaparib Monotherapy as Maintenance Treatment in Patients With Newly Diagnosed Ovarian Cancer (ATHENA–MONO/GOG-3020/ENGOT-ov45). Monk BJ, Parkinson C, Lim MC, et al. DOI: 10.1200/JCO.2022.40.17_suppl.LBA5500 Journal of Clinical Oncology 40, no. 17_suppl (June 10, 2022) LBA5500-LBA5500. Published online June 08, 2022.