FDA Approves IMFINZI® for Advanced Small Cell Lung Cancer

SUMMARY: The FDA on March 27, 2020 approved IMFINZI® (Durvalumab) in combination with Etoposide and either Carboplatin or Cisplatin as first-line treatment for patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC). The American Cancer Society estimates that for 2020 about 228,820 new cases of lung cancer will be diagnosed and about 135,720 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Small cell lung cancer (SCLC) accounts for approximately 13-15% of all lung cancers and is aggressive. Patients with extensive stage SCLC are often treated with a combination of Carboplatin or Cisplatin with Etoposide as first line treatment and the tumor response rates are as high as 60-80%. However, majority of the patients relapse within months of completing initial therapy, with a median Overall Survival (OS) of approximately 10 months. Patients often receive HYCAMTIN® (Topotecan) for recurrent or progressive SCLC (second-line treatment) and after failure on second-line therapy, treatment options are limited. The 5 year survival rate for Extensive Stage SCLC (ES-SCLC) is less than 5%, with a median survival of 9-10 months from the time of diagnosis.Unleashing-T-Cell-Function-with-PD-1-and-PD-L1-Antibodies

Based on the premise that SCLC has a high mutation rate, it was hypothesized that these tumors may be immunogenic and more recently immunotherapy with checkpoint inhibitors has demonstrated clinical activity in Extensive Stage SCLC. IMFINZI® (Durvalumab) is a selective, high-affinity, human IgG1 monoclonal antibody, that blocks the binding of Programmed Death Ligand 1 (PD-L1) to Programmed Death 1 (PD-1) receptor and CD80, thereby unleashing the T cells to recognize and kill tumor cells.

IMFINZI® is approved by the FDA for the treatment of patients with locally advanced, unresectable Stage III Non-Small Cell Lung Cancer, who have not progressed following chemoradiotherapy. Additionally, IMFINZI® is also approved for the treatment of patients with locally advanced or metastatic Urothelial carcinoma who have disease progression during or following Platinum-containing chemotherapy, or who have disease progression within 12 months of neoadjuvant or adjuvant treatment with Platinum-containing chemotherapy.

This present FDA approval was based on CASPIAN trial, which is a multicenter, randomized, controlled, open-label, Phase III study, in which the efficacy of IMFINZI® with or without CTLA-4 inhibitor Tremelimumab, in combination with Etoposide plus either Cisplatin or Carboplatin (Platinum-Etoposide), was compared to chemotherapy alone, in treatment-naive patients with ES-SCLC.
Patients were randomly assigned in a 1:1:1 ratio to IMFINZI® plus Platinum-Etoposide, IMFINZI® plus Tremelimumab plus Platinum-Etoposide, or Platinum-Etoposide alone. This study allocated 268 patients to the IMFINZI® plus Platinum-Etoposide group and 269 patients to the Platinum-Etoposide group. Treatment with Platinum-Etoposide consisted of Etoposide 80-100 mg/m2 IV on days 1-3 of each cycle with investigator’s choice of either Carboplatin AUC 5-6 mg/mL per min or Cisplatin 75-80 mg/m2 IV administered on day 1 of each cycle. Patients received up to four cycles of Platinum-Etoposide along with IMFINZI® 1500 mg IV with or without Tremelimumab 75 mg IV every 3 weeks, followed by maintenance IMFINZI® 1500 mg IV every 4 weeks in the immunotherapy treatment groups, or up to six cycles of Platinum-Etoposide IV every 3 weeks plus Prophylactic Cranial Irradiation (at the treating physicians discretion), in the Platinum-Etoposide control group. The median patient age was 62 years and 10% of the patients had CNS metastases. PCI was administered to 8% of patients in the Platinum-Etoposide group. The Primary endpoint was Overall Survival (OS). Additional efficacy outcome measures included Progression Free Survival (PFS) and Objective Response Rate (ORR). The authors reported the results for the IMFINZI® plus Platinum-Etoposide group, compared to the Platinum-Etoposide group, from a planned interim analysis.

The median OS was 13.0 months in the IMFINZI® plus chemotherapy group, compared with 10.3 months in the chemotherapy alone group (HR=0.73; P=0.0047), with a 27% reduction in the risk of death.
Approximately 34% of patients who received IMFINZI® were alive at 18 months as compared to 25% in the control arm of the trial. Additionally, IMFINZI® plus chemotherapy demonstrated a higher PFS rate at 12 months (17.5% versus 4.7%), a 10.3% increase in confirmed ORR (67.9% versus 57.6%), and improved Duration of Response at 12 months (22.7% versus 6.3%). The most common adverse reactions noted were nausea, fatigue, asthenia, and alopecia.

It was concluded that the addition of IMFINZI® to first line Platinum-Etoposide chemotherapy combination significantly improved Overall Survival in patients with Extensive Stage-Small Cell Lung Cancer, when compared to chemotherapy alone.

Durvalumab plus platinum-etoposide versus platinum-etoposide in first-line treatment of extensive-stage small-cell lung cancer (CASPIAN): a randomised, controlled, open-label, phase 3 trial. Paz-Ares L, Dvorkin M, Chen Y, CASPIAN investigators, et al. Lancet. 2019;394:1929-1939

FDA Approves REBLOZYL® for Patients with Lower-Risk Myelodysplastic Syndromes

SUMMARY: The FDA on April 3, 2020 approved REBLOZYL® (Luspatercept-aamt) for the treatment of anemia, failing an Erythropoiesis Stimulating Agent, and requiring two or more RBC units over 8 weeks, in adult patients with very low- to intermediate-risk MyeloDysplastic Syndromes with Ring Sideroblasts (MDS-RS) or with Myelodysplastic/Myeloproliferative neoplasm with Ring Sideroblasts and Thrombocytosis (MDS/MPN-RS-T).

It is estimated that in the US approximately 13,000 people are diagnosed with MyeloDysplastic Syndromes (MDS) each year. MyeloDysplastic Syndromes are a heterogenous group of stem cell disorders characterized by marrow failure resulting in cytopenias with associated cytogenetic abnormalities, and abnormal cellular maturation with morphologic changes in clonal cells. Majority of the individuals diagnosed with MDS are aged 65 years and older and die as a result of infection and/or bleeding consequent to bone marrow failure. About a third of patients with MDS develop Acute Myeloid Leukemia (AML).

Patients with Lower-risk MDS (Revised IPSS-Very Low, Low, or Intermediate risk ) often present with symptomatic anemia and these patients are in chronic need for RBC transfusions which in turn can result in iron overload and can have a negative impact on quality of life and Overall Survival. These patients are treated with Erythropoiesis Stimulating Agents (ESAs) as first line therapy. ESAs such as Darbepoetin alfa and Epoetin alfa are re-engineered and recombinant DNA technology products of Erythropoietin (EPO), and they stimulate erythropoiesis by binding and activating the EPO receptor. However, transfusion-dependent patients with serum EPO levels above 200 U per liter are less likely to respond to ESAs. Additionally, patients with MDS with ring sideroblasts have a shorter median duration of response to ESAs, than those who do not have ring sideroblasts. Patients with Lower-risk MDS with chromosome 5q deletion (del 5q) who are transfusion dependent are treated with Lenalidomide, regardless of previous treatment with ESAs. In contrast, only 39% of patients with non-del(5q) Lower-risk MDS receive second line therapy besides RBC transfusions, and there are few treatment options for patients who are refractory to, unresponsive to, or ineligible for ESAs. There is therefore an unmet clinical need for safe and effective treatment options, to reduce the RBC transfusion burden in these patients.Luspartercept-Restores-Red-Blood-Cell's-Ability-to-Mature

Signaling by the SMAD2 and SMAD3 pathway exerts an inhibitory effect on red cell maturation. This pathway is constitutively activated in the bone marrow cells of patients with MDS and diseases associated with ineffective erythropoiesis such as β-thalassemia. REBLOZYL® (Luspatercept) is a recombinant soluble fusion protein and is first-in-class erythroid maturation agent that enhances erythropoiesis by promoting late-stage Red Blood Cell precursor differentiation and maturation. It targets select Transforming Growth Factor (TGF)-β superfamily ligands such as GDF11, that regulate late-stage erythropoiesis. This results in a reduction in aberrant SMAD2 and SMAD3 signaling, thereby promoting late-stage RBC precursor differentiation and maturation. In a Phase II study, treatment of Lower-risk MDS patients with REBLOZYL® resulted in 38% of patients being transfusion independent for 8 weeks or longer and this benefit was even more so among patients with 15% or more ring sideroblasts.

The MEDALIST trial is a randomized, double-blind, placebo-controlled Phase III study which evaluated the efficacy and safety of REBLOZYL® in patients with anemia secondary to MDS, defined as Very Low-Risk, Low-Risk, or Intermediate-Risk with Ring Sideroblasts, according to the Revised International Prognostic Scoring System (R-IPSS). Eligible patients were refractory, intolerant, or ineligible to receive ESAs and required RBC transfusions. A total of 229 patients (N=229) were randomized 2:1 to receive either REBLOZYL® at a starting dose level of 1mg/kg SC with titration up to 1.75 mg/kg if needed (N=153), or placebo SC (N=76), every 3 weeks for 24 weeks or more. The median age was 71 years and median time from diagnosis was 41.8 months. Approximately 95% of patients had previously received ESAs and 90% had an SF3B1 mutation. SF3B1 mutation defines a homogeneous subgroup of MDS patients with Ring Sideroblasts, who have isolated erythroid dysplasia and favorable prognosis. The Primary endpoint was RBC transfusion independence for 8 weeks or more between week 1 and 24. A key Secondary endpoint was RBC transfusion independence for 12 weeks or more between week 1 and 24.

Among those receiving REBLOZYL®, 38% achieved the Primary endpoint of RBC transfusion independence for 8 weeks or more, compared with 13% receiving placebo (P<0.0001). Further among those receiving REBLOZYL®, 28% achieved the key Secondary endpoint of RBC transfusion independence for 12 weeks or more compared with 8% receiving placebo (P<0.001). The median duration of the longest, single continuous period of response to REBLOZYL® was 30.6 weeks, and 13.6 weeks in the placebo group. Among patients who had a baseline transfusion burden of 4 to less than 6 units per 8 weeks, 37% of those in the REBLOZYL® group and 4% of those in the placebo group had a response. Additionally, patients receiving REBLOZYL® were more likely to achieve an mHI-E (modified Hematologic Improvement-Erythroid) response, (defined as a reduction in transfusion of 4 or more RBC units per 8 weeks or a mean hemoglobin increase of 1.5 g/dL or more per 8 weeks, in the absence of transfusions), compared with patients receiving placebo (53% versus 12% during weeks 1-24; P<0.0001). A mean increase in hemoglobin level of at least 1 g/dL during weeks 1 to 24 was noted in 35% of patients who received REBLOZYL® and in 8% of patients who received placebo. The most common adverse events of any grade associated with REBLOZYL® included fatigue, diarrhea, asthenia, nausea and dizziness, and the incidence of adverse events decreased over time.

It was concluded that treatment with REBLOZYL® significantly reduced the severity of anemia in patients with Lower-risk MDS with ring sideroblasts, who had been RBC transfusion-dependent, and who had disease that was refractory to, or unlikely to respond to ESAs. Luspatercept in Patients with Lower-Risk Myelodysplastic Syndromes. Fenaux P, Platzbecker U, Mufti GJ, et al. N Engl J Med 2020; 382:140-151

IMFINZI® (Durvalumab)

The FDA on March 30, 2020 approved IMFINZI® in combination with Etoposide and either Carboplatin or Cisplatin as first-line treatment of patients with Extensive-Stage Small Cell Lung Cancer (ES-SCLC). IMFINZI® is a product of AstraZeneca.

OPDIVO® and YERVOY®

The FDA on March 10, 2020 granted accelerated approval to the combination of OPDIVO® (Nivolumab) and YERVOY® (Ipilimumab) for patients with Hepatocellular Carcinoma (HCC), who have been previously treated with NEXAVAR® (Sorafenib). Both OPDIVO® and YERVOY® are products of Bristol-Myers Squibb Co.

NERLYNX® (Neratinib)

The FDA on February 25, 2020 approved NERLYNX® in combination with XELODA® (Capecitabine) for adult patients with advanced or metastatic HER2-positive Breast Cancer, who have received two or more prior anti-HER2 based regimens in the metastatic setting. NERLYNX® is a product of Puma Biotechnology, Inc.

SARCLISA® (Isatuximab-irfc)

The FDA on March 2, 2020 approved SARCLISA® in combination with POMALYST® (Pomalidomide) and Dexamethasone for adult patients with Multiple Myeloma, who have received at least two prior therapies including REVLIMID® (Lenalidomide) and a Proteasome Inhibitor. SARCLISA® is a product of Sanofi-Aventis U.S. LLC.

TAZVERIK® (Tazemetostat)

The FDA on January 23, 2020 granted accelerated approval to TAZVERIK® for adults and pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma, not eligible for complete resection. TAZVERIK® is a product of Epizyme, Inc.

AYVAKIT® (Avapritinib)

The FDA on January 9, 2020 approved AYVAKIT® for adults with unresectable or metastatic GastroIntestinal Stromal Tumor (GIST) harboring a Platelet-Derived Growth Factor Receptor Alpha (PDGFRA) exon 18 mutation, including D842V mutations. AYVAKIT® is a product of Blueprint Medicines Corporation.

KEYTRUDA® (Pembrolizumab)

he FDA on January 8, 2020 approved KEYTRUDA® for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, Non-Muscle Invasive Bladder Cancer (NMIBC) with Carcinoma In Situ (CIS), with or without papillary tumors, who are ineligible for or have elected not to undergo cystectomy. KEYTRUDA® is a product of Merck & Co. Inc.

ENHERTU® Highly Effective in Heavily Pretreated HER2-Positive Advanced Breast Cancer 

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (13%) will develop invasive breast cancer during their lifetime. Approximately 276,480 new cases of invasive female breast cancer will be diagnosed in 2020 and about 42,170 women will die of the disease. 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) and KADCYLA® (ado-Trastuzumab emtansine). 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. There is however no standard treatment option for this patient population following progression on KADCYLA®.Mechanism-of-Action - ENHERTU
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®, 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, minimizing systemic exposure. In a Phase 1 dose-finding study involving patients with advanced HER2-positive breast cancer, treatment with ENHERTU® resulted in a confirmed response rate was 59.5%, and the median response duration was 20.7 months. However, the efficacy of ENHERTU® in patients with HER2-positive metastatic breast cancer, previously treated with KADCYLA® remained unclear.
DESTINY-Breast 01 study is a multicenter, single-arm, Phase II registration trial, in which 184 patients with HER2-positive, metastatic breast cancer, who had received two or more prior HER2 targeted therapies including KADCYLA®, were enrolled. Patients received ENHERTU® 5.4 mg/kg IV every 3 weeks until disease progression or unacceptable toxicity. The median age was 55 years, 53% had Hormone Receptor-positive tumors and the median number of previous lines of therapy for metastatic disease was SIX and included KADCYLA® (100%), Trastuzumab (100%), Pertuzumab (66%), and other anti-HER2 therapies (54%). The Primary end point was Objective Response Rate (ORR) assessed by Independent Central Review and Secondary endpoints included Duration of Response, Progression Free Survival (PFS) and Overall Survival (OS). The median follow up was 11.1 months.
The ORR was 60.9%, with 6% Complete Responses and 54.9% Partial Responses. The median time to response was 1.6 months and the median response duration was 14.8 months. The median PFS was 16.4 months the median OS was not reached at the time of this publication. The efficacy results were consistent across all key subgroups, including patients who had received previous PERJETA® (Pertuzumab) therapy. The most Grade 3 or higher adverse events were cytopenias, nausea, diarrhea and Interstitial Lung Disease.
It was concluded that ENHERTU® has a high level of clinical efficacy with a durable antitumor activity in a heavily pretreated patient population with HER2-positive metastatic breast cancer. The FDA in December 2019, granted accelerated approval to ENHERTU® (Trastuzumab deruxtecan) for patients with unresectable or metastatic HER2-positive breast cancer, who have received two or more prior anti-HER2-based regimens in the metastatic setting. Trastuzumab Deruxtecan in Previously Treated HER2-Positive Breast Cancer. Modi S, Saura C, Yamashita T, et al. for the DESTINY-Breast01 Investigators. N Engl J Med 2020;382:610-621.