Author: RR

FDA Approves Nivolumab for Adjuvant Treatment of Stage IIB/C Melanoma

RR

SUMMARY: The FDA on October 13, 2023, approved Nivolumab (OPDIVO®) for the adjuvant treatment of completely resected Stage IIB/C melanoma in patients 12 years and older. The American Cancer Society’s estimates that for 2023, about 97,610 new cases of melanoma of the skin will be diagnosed in the United States and 7,990 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.

Patients with resected Stage IIB/C disease comprise a significant group of patients at significant risk of recurrence. Patients with Stage IIB disease have primary tumors that are more than 2 mm and 4 mm or less in thickness with ulceration (T3b) or more than 4 mm in thickness without ulceration (T4a). Patients with Stage IIC disease have primary tumors more than 4 mm in thickness with ulceration (T4b). Although Stage II melanoma is less advanced than Stage III, the 5-year risk of recurrence in patients with stage IIB or Stage IIC disease without adjuvant therapy is approximately 35% and 50% respectively. The 5-year Melanoma-Specific Survival (MSS) rates for patients with Stage IIB/IIC disease are similar to those for Stage IIIA, Stage IIIB and Stage IIIC disease.

Immune Checkpoint Inhibitors are the standard of care adjuvant treatment for high-risk, resected, Stage III melanoma. In the KEYNOTE-054 trial, the 5-year Relapse Free Survival (RFS) with adjuvant Pembrolizumab was 55.4% versus 38.3% with placebo, in patients with completely resected, Stage IIIA (more than 1 mm lymph node metastasis), IIIB or IIIC Melanoma. In the CHECKMATE-238 trial, the 4-year RFS rate was of 51.7% for Nivolumab versus 41.2% for ipilimumab among patients with resected Stage IIIB/C and IV melanoma.

CHECKMATE-76K is an ongoing, randomized, double-blind, Phase III study conducted to evaluate the efficacy of Nivolumab versus placebo as adjuvant treatment for patients with resected Stage IIB/C melanoma. In this study, 790 eligible patients were randomized (2:1) to Nivolumab 480 mg (N=526) or placebo (N=264) by IV infusion every 4 weeks for up to 1 year or until disease recurrence or unacceptable toxicity. Patient characteristics at baseline were well balanced between treatment groups and 50.5% had nodular melanoma, 39% had Stage IIC disease and patients were stratified by tumor category. The Primary endpoint was investigator-assessed Recurrence-Free Survival (RFS). Secondary endpoints included Distant Metastasis-Free Survival (DMFS) and Safety.

At a minimum follow up of 7.8 months, CheckMate 76K met its primary endpoint and Nivolumab significantly improved RFS versus placebo. Nivolumab demonstrated a 58% reduction in the risk of recurrence or death versus placebo in patients with resected stage IIB/C melanoma (HR = 0.42; P < 0.0001). The 12-month RFS was 89.0% for nivolumab and 79.4% for placebo. The benefit with nivolumab over placebo was observed across all pre-specified subgroups, including all disease Stages and T-category subgroups. Adjuvant Nivolumab demonstrated significant benefit in those with stage IIC disease, head and neck primaries or nodular disease, who are all considered to be at a higher absolute recurrence risk. Additionally, there was a clinically meaningful improvement in the Distant Metastasis-Free Survival with Nivolumab versus placebo (HR = 0.47). Further, a lower proportion of patients treated with nivolumab had multiple lesions detected at first recurrence versus those treated with placebo (3.4% versus 9.1%). Adverse events were similar to that observed in patients with resected stage III or stage IV disease and similar to the established anti-PD-1 monotherapy profile.

It was concluded that adjuvant Nivolumab significantly improved Relapse Free Survival as well as Distant Metastasis-Free Survival in patients with resected Stage IIB/C melanoma and this clinical benefit was observed across disease subgroups, including all T categories.

Adjuvant nivolumab in resected stage IIB/C melanoma: primary results from the randomized, phase 3 CheckMate 76K trial. Kirkwood, J.M., Del Vecchio, M., Weber, J. et al. Nat Med (2023). https://doi.org/10.1038/s41591-023-02583-2

Amivantamab plus Chemotherapy with and without Lazertinib after Progression on Osimertinib in Advanced 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 mutations and 90% of these mutations are either exon 19 deletions or L858R substitution mutation in exon 21.

Epidermal Growth Factor Receptor (EGFR) plays an important role in regulating cell proliferation, survival and differentiation, and is overexpressed in a variety of epithelial malignancies. EGFR targeted Tyrosine Kinase Inhibitors (TKIs) such as Gefitinib, Erlotinib, Afatinib, Dacomitinib and Osimertinib target the EGFR signaling cascade. However, patients eventually will develop drug resistance due to new EGFR mutations. Another important cause of drug resistance to TKIs is due to the activation of parallel RTK (Receptor Tyrosine Kinase) pathways such as Hepatocyte Growth Factor/Mesenchymal-Epithelial Transition factor (HGF/MET) pathway, thereby bypassing EGFR TKI inhibitors. These patients are often treated with platinum-based chemotherapy as the next line of therapy, resulting in a median Progression Free Survival of 5 months.

Amivantamab (RYBREVANT®) is a fully-human bispecific antibody directed against EGFR and MET receptors. 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. Amivantamab also engages effector cells such as Natural Killer cells, monocytes, and macrophages via its optimized Fc domain. Amivantamab demonstrated activity against a wide range of activating and resistance mutations in EGFR-mutated NSCLC, and in patients with MET exon 14 skip mutations, and is approved for the treatment of patients with EGFR exon 20 insertion mutations, whose disease progressed on or after platinum-based chemotherapy.

Lazertinib is a highly selective, third-generation TKI that penetrates the CNS, with demonstrated efficacy in activating EGFR mutations and acquired T790M “gatekeeper” point mutation. Combining Amivantamab with Lazertinib has been shown to provide a synergistic benefit by targeting the extracellular and catalytic EGFR domains. In early phase studies, Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy demonstrated an Objective Response Rate of 44% and 50% in advanced and refractory NSCLC, and in patients whose disease had progressed on prior TKIs, respectively.

MARIPOSA-2 is a global, randomized, Phase 3 trial, conducted to assess the efficacy and safety of Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy versus chemotherapy alone, in patients with EGFR-mutated advanced NSCLC, whose disease had progressed on or after Osimertinib monotherapy. Amivantamab is a large molecule and was not expected to readily cross the blood-brain barrier. This was one of the main reasons for the addition of Lazertinib, a known CNS-active TKI, to Amivantamab plus chemotherapy. A total of 657 patients (N=657) with EGFR-mutated (exon 19 deletions or L858R substitution mutations) locally advanced or metastatic NSCLC, after disease progression on Osimertinib, were randomized 2:2:1 to receive either Amivantamab along with Lazertinib and chemotherapy (N=263), chemotherapy alone (N=263), or Amivantamab plus chemotherapy (N=131). Patients received Amivantamab 1400 mg IV (1750 mg for body weight 80 kg or greater) weekly for the first 4 weeks, then 1750 mg (2100 mg for body weight 80 kg or greater) every 3 weeks starting at cycle 3 (week 7). The first Amivantamab infusion was split over 2 days, with 350 mg IV on cycle 1, day 1 and the remainder on cycle 1, day 2. Lazertinib was administered at 240 mg orally daily. Chemotherapy consisted of Carboplatin AUC5 IV, starting on day 1 every 3 weeks for the first 4 cycles along with Pemetrexed 500 mg/m2 IV every 3 weeks until disease progression. The median age was 62 years, 48% of patients were Asian, about 45% of patients had a history of brain metastases, and approximately 70% of patients had Osimertinib as first line treatment and 30% had Osimertinib as second line treatment. Randomization was stratified by Osimertinib line of therapy (first or second), race (Asian or non-Asian), and history of brain metastasis (yes or no). All three treatment groups were well balanced. The dual Primary endpoints were Progression Free Survival (PFS) of Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy, versus chemotherapy alone. Secondary endpoints included Objective Response Rate (ORR), Duration of Response, Overall Survival (OS) and Safety.

At a median follow-up of 8.7 months, the PFS was significantly longer for Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy versus chemotherapy alone (HR for disease progression or death=0.48 and 0.44, respectively; P<0.001 for both; median of 6.3 and 8.3 versus 4.2 months, respectively). The Objective Response Rate was significantly higher for Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy versus chemotherapy alone (64% and 63% versus 36%, respectively; P<0.001 for both). The median intracranial PFS was 12.5 and 12.8 versus 8.3 months for Amivantamab plus chemotherapy and Amivantamab, Lazertinib plus chemotherapy versus chemotherapy alone (HR for intracranial disease progression or death=0.55 and 0.58, respectively). The researchers postulated that the mechanism by which Amivantamab improves intracranial PFS could either be through direct antitumor effects or indirectly through immune-based mechanisms. The most common adverse events with the Amivantamab combinations were cytopenias, infusion-related reactions and venous thromboembolism. The researchers recommend prophylactic anticoagulation.

It was concluded that Amivantamab plus chemotherapy, as well as Amivantamab, Lazertinib plus chemotherapy, significantly improved Progression Free Survival (PFS) and intracranial PFS, compared with chemotherapy alone, in patients with EGFR-mutated advanced NSCLC with disease progression on or after Osimertinib. The authors added that MARIPOSA-2 is the first study to demonstrate improved PFS versus chemotherapy, after disease progression on Osimertinib.

Amivantamab plus chemotherapy with and without lazertinib in EGFR-mutant advanced NSCLC after disease progression on osimertinib: Primary results from the phase 3 MARIPOSA-2 study. Passaro A, Wang J, Wang Y, et al. Annals of Oncology. 2023. DOI:https://doi.org/10.1016/j.annonc.2023.10.117

FDA Approves Ivosidenib for Myelodysplastic Syndromes

RR

SUMMARY: The FDA on October 24, 2023, approved Ivosidenib (TIBSOVO®) for adult patients with Relapsed or Refractory MyeloDysplastic Syndromes (MDS) with a susceptible Isocitrate DeHydrogenase-1 (IDH1) mutation, as detected by an FDA-approved test. The FDA also approved the Abbott RealTime IDH1 Assay as a companion diagnostic device to select patients for Ivosidenib.

It is estimated that in the US approximately 13,000 people are diagnosed with MyeloDysplastic Syndromes (MDS) each year. The prevalence has been estimated to be from 60,000 to 170,000 in the US. MyeloDysplastic Syndromes are a heterogenous group of stem cell disorders characterized by marrow failure resulting in cytopenias, mainly symptomatic anemia, with associated cytogenetic abnormalities, and abnormal cellular maturation with morphologic changes in clonal cells. Majority of the individuals diagnosed with MDS are 65 years or 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).

The International Prognostic Scoring System (IPSS) for MDS has 4 risk groups based on Total Risk Score (Low, Intermediate-1, Intermediate-2 and High). The three prognostic factors scored to predict the course of the patient’s disease include, percentage of blast cells in the bone marrow, type of chromosomal changes in the marrow cells and number of cytopenias (anemia, neutropenia or thrombocytopenia). Patients with low-risk MDS have an indolent disease course with a median survival of about 6 years with no therapeutic intervention. Patients with intermediate and higher-risk disease however have a shorter median survival even with treatment, with approximately a third of the patients progressing to AML within 3 years.

Patients with Low-risk MDS often present with symptomatic anemia and these patients are in chronic need for RBC transfusions. 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 200U per liter are less likely to respond to ESAs. A majority of patients with higher-risk MDS are treated with hypomethylating agents such as Azacitidine and Decitabine and these agents can favorably modify the natural history of the disease, and have been shown to improve survival. However, outcomes are poor and no therapies currently exist for patients with Isocitrate Dehydrogenase 1-mutant Relapsed or Refractory MDS, following failure on a hypomethylating agent.

Isocitrate DeHydrogenase (IDH) is a metabolic enzyme that helps generate energy from glucose and other metabolites, by catalyzing the conversion of Isocitrate to Alpha-Ketoglutarate. Alpha-ketoglutarate is required to properly regulate DNA and histone methylation, which in turn is important for gene expression and cellular differentiation. IDH mutations lead to aberrant DNA methylation and altered gene expression thereby preventing cellular differentiation, with resulting immature undifferentiated cells. IDH mutations can thus promote leukemogenesis in Acute Myeloid Leukemia and tumorigenesis in solid tumors and can result in inferior outcomes. There are three isoforms of IDH. IDH1 is mainly found in the cytoplasm, as well as in peroxisomes, whereas IDH2 and IDH3 are found in the mitochondria, and are a part of the Krebs cycle. Approximately 20% of patients with AML, 70% of patients with Low-grade Glioma and secondary Glioblastoma, 50% of patients with Chondrosarcoma, 20% of patients with Intrahepatic cholangiocarcinoma, 30% of patients with Angioimmunoblastic T-cell lymphoma and 8% of patients with Myelodysplastic syndromes/Myeloproliferative neoplasms, are associated with IDH mutations.

Ivosidenib is a first-in-class, oral, potent, targeted, small-molecule inhibitor of mutant IDH1. The FDA in 2018, approved Ivosidenib for adult patients with Relapsed or Refractory AML with a susceptible IDH1 mutation, and in 2019 approved Ivosidenib for newly diagnosed AML with a susceptible IDH1 (Isocitrate DeHydrogenase-1) mutation, in patients who are at least 75 years old or who have comorbidities that preclude the use of intensive induction.

The present FDA approval is supported by a pivotal Phase 1, open-label, multinational study, in which the safety, tolerability, and clinical activity of Ivosidenib was evaluated among patients with Relapsed or Refractory Myelodysplastic syndromes with an IDH1 mutation. In this study 18 eligible patients (N=18) received Ivosidenib 500 mg orally daily, continuous for 28-day cycles, until disease progression, unacceptable toxicity, or Hematopoietic Stem Cell Transplantation. The median treatment duration was 9.3 months. One patient underwent a Stem Cell Transplantation following Ivosidenib. IDH1 mutations were detected in peripheral blood or bone marrow by a local or central diagnostic test and confirmed retrospectively by the Abbott RealTime IDH1 Assay. The median age was 73 years and majority of patients had intermediate or high IPSS-R score at the time of screening for the study. The Primary efficacy end point was the Complete Response (CR) plus Partial Response (PR) rate. Secondary endpoints included duration of CR plus PR, duration of transfusion independence, and time to transfusion independence.

All observed responses were Complete Responses. The CR rate was 38.9%. The median time to Complete Response was 1.9 months and at the time of data cutoff, the median duration of Complete Responses was not estimable and ranged from 1.9 to 80.8+ months. Additionally, of the 9 patients who were transfusion dependent with Red Blood Cells or platelets at baseline, 67% became RBC and platelet transfusion independent during any 56-day post-baseline period. Of the 9 patients independent of both RBC and platelet transfusions at baseline, 78% remained transfusion independent during any 56-day post-baseline period. The most common adverse reactions included GI toxicities such as mucositis, diarrhea, constipation and nausea, fatigue, arthralgia, myalgia, cough, and rash. Differentiation syndrome was rare and manageable. It should be noted that Ivosidenib can also cause QTc prolongation.

It was concluded from this study that Ivosidenib induced durable remissions including a substantial proportion of Complete Remissions with an acceptable safety profile, in patients with Relapsed or Refractory Myelodysplastic syndromes with an IDH1 mutation. Further, a significant proportion of patients became or remained transfusion independent. This is the first targeted therapy approved for this indication.

UPDATED SUBSTUDY RESULTS FOR IVOSIDENIB IN IDH1-MUTANT RELAPSED/REFRACTORY MYELODYSPLASTIC SYNDROME. Dinardo C, Roboz G, Watts JM, et al. Hemasphere. 2023 Aug; 7(Suppl): e75740ab. DOI: 10.1097/01.HS9.0000969800.75740.ab.

ROZLYTREK® (Entrectinib)

RR

The FDA on October 20, 2023, granted accelerated approval to ROZLYTREK® for pediatric patients older than 1 month with solid tumors that have a Neurotrophic Tyrosine Receptor Kinase (NTRK) gene fusion without a known acquired resistance mutation, are metastatic or where surgical resection is likely to result in severe morbidity, and have progressed following treatment or have no satisfactory standard therapy. In August 2019, FDA granted accelerated approval to ROZLYTREK® for pediatric patients 12 years of age and older for this indication. ROZLYTREK® is a product of Genentech Inc.

TEMODAR® (Temozolomide)

RR

The FDA on September 14, 2023, approved updated labeling for TEMODAR® under Project Renewal, an Oncology Center of Excellence (OCE) initiative aimed at updating labeling information for older oncology drugs to ensure information is clinically meaningful and scientifically up-to-date. This is the second drug to receive a labeling update under this pilot program. The first drug that received approval under Project Renewal was XELODA® (Capecitabine). TEMODAR® is a product of Merck & Co., Inc..