FDA Approves RYBREVANT® plus Chemotherapy for EGFR-Mutated NSCLC

SUMMARY: The FDA on September 19, 2024 approved Amivantamab-vmjw (RYBREVANT®) with Carboplatin and Pemetrexed for adult patients with locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) exon 19 deletions or exon 21 L858R substitution mutations, whose disease has progressed on or after treatment with an EGFR tyrosine kinase inhibitor. 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 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers.

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.

The efficacy of Amivantamab was assessed in the Phase 3 MARIPOSA-2 trial, a multicenter, open-label study involving 657 patients. These participants, all with EGFR-mutant NSCLC, who had progressed on Osimertinib treatment, were randomly assigned in a 1:2:2 ratio to receive either Amivantamab with Carboplatin and Pemetrexed (referred to as Amivantamab plus chemotherapy-N=131), Carboplatin and Pemetrexed alone (chemotherapy alone-N=263), or Amivantamab combined with other regimens (N=263). Eligible patients had documented presence of EGFR exon 19 deletion or exon 21 L858R mutation and experienced disease progression after receiving Osimertinib as their most recent line of therapy. 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. Chemotherapy consisted of Carboplatin AUC 5 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 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), and race (Asian or non-Asian). All three treatment groups were well balanced. The Primary endpoint of the study was Progression-Free Survival (PFS), assessed by Blinded Independent Central Review (BICR). Key Secondary endpoints included Overall Survival (OS), Overall Response Rate (ORR), Time to Treatment Discontinuation (TTD), Time to Subsequent Therapy (TTST), Progression-Free Survival after first subsequent therapy (PFS2) and Time to Symptomatic Progression (TTSP).

At a median follow-up of 8.7 months, the PFS was significantly longer for Amivantamab plus chemotherapy versus chemotherapy alone. The median PFS was 6.3 months in the Amivantamab plus chemotherapy group and 4.2 months in the chemotherapy alone group (HR for disease progression or death=0.48; P<0.0001), indicating a a 52% reduction in the risk of progression or death. The ORR was significantly higher in the Amivantamab plus chemotherapy group at 53%, compared to 29% in the chemotherapy alone group (P<0.0001).

In the prespecified second interim analysis, a numerical improvement in OS was noted for the Amivantamab plus chemotherapy group with a median OS of 17.7 months compared to 15.3 months for the chemotherapy alone group (HR=0.73; P=0.039). However, this did not meet the prespecified significance level.

With regards to Post-Progression Endpoints, the median TTD was significantly longer in the Amivantamab plus chemotherapy group versus chemotherapy alone group (10.4 months versus 4.5 months; HR=0.42; P<0.0001). The Median TTST was also prolonged in the Amivantamab plus chemotherapy group versus chemotherapy alone group (12.2 months compared to 6.6 months HR=0.51; P< 0.0001). The median PFS2 was significantly longer in the Amivantamab plus chemotherapy group compared to the chemotherapy alone group (16.0 months versus 11.6 months (HR= 0.64; P=0.002). Common adverse reactions observed in patients receiving Amivantamab plus chemotherapy included rash, infusion-related reactions, fatigue, nail toxicity, nausea, constipation, edema, stomatitis, decreased appetite, musculoskeletal pain, vomiting, and COVID-19 infection.

In conclusion, the results from the MARIPOSA-2 trial provide compelling evidence for the use of Amivantamab in combination with Carboplatin and Pemetrexed in the treatment of advanced EGFR-mutant NSCLC post-Osimertinib progression. While the PFS outcomes were significantly improved, the OS benefits, promising as they may be, require further follow-up for conclusive results. The final Overall Survival analysis will be eagerly awaited, as it will further illuminate the long-term efficacy of this treatment approach.

Amivantamab plus chemotherapy vs chemotherapy in EGFR-mutated, advanced non-small cell lung cancer after disease progression on osimertinib: Second interim overall survival from MARIPOSA-2. Popat S, Reckamp KL, Califano R, et al. Presented at: 2024 ESMO Congress; September 13-17, 2024; Barcelona, Spain. LBA54.

Sotorasib plus Panitumumab in Refractory Colorectal Cancer with Mutated KRAS G12C

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

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

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

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

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

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

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

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

TAGRISSO® after Chemoradiotherapy in Stage III EGFR Mutated Non-Small Cell Lung Cancer

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 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Approximately one third of all patients with NSCLC have Stage III, locally advanced disease at the time of initial presentation and 60 to 90% of these patients have unresectable disease. These patients are treated with concurrent chemoradiotherapy (CRT) followed by consolidation therapy with Durvalumab (IMFINZI®) in patients without progression, as this regimen confers an Overall Survival advantage, and is considered the standard of care (PACIFIC trial).

EGFR (Epidermal Growth Factor Receptor) mutations are found in up to one third of patients with unresectable Stage III NSCLC. There are currently no approved targeted treatments for patients with unresectable Stage III EGFR-mutated NSCLC. The current standard of care, which includes consolidation therapy with Durvalumab, may not offer clear benefits to this subset of patients with EGFR mutations.

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

LAURA was a global, randomized, double-blind, placebo-controlled, multicenter Phase III trial conducted to assess the efficacy and safety of Osimertinib in patients with unresectable Stage III NSCLC harboring EGFR mutations (EGFR exon 19 deletion or exon 21 L858R mutation). The trial enrolled patients who had not experienced disease progression during or after definitive platinum-based chemoradiotherapy (CRT). A total of 216 patients who had undergone CRT were randomly assigned 2:1 to receive Osimertinib 80 mg orally once daily (N=143) or placebo once per day (N=73). Treatment was continued until Blinded Independent Central Review (BICR)–assessed disease progression, unacceptable toxicity, or other discontinuation criteria were met. Upon disease progression, patients in the placebo arm were permitted to receive Osimertinib, allowing for crossover therapy. Stratification factors included method of CRT (concurrent versus sequential) and disease Stage (IIIA versus IIIB/C). Both treatment groups were well balanced. The median patient age was 63 years, approximately 60% of participants were female, 83% were Asian, 69% had never smoked and 85% had Stage IIIA and B disease. Majority of patients received concurrent CRT rather than sequential CRT. The Primary end point was Progression Free Survival (PFS) as assessed by BICR. Key Secondary end points included Overall Survival (OS), survival without progression of CNS disease (CNS Progression Free Survival), Objective Response Rate (ORR), Duration of Response, Quality of Life, and Safety.

Treatment with Osimertinib resulted in significant PFS improvement compared to placebo. The median PFS was 39.1 months in the Osimertinib group versus 5.6 months in the placebo group, representing an 84% reduction in the risk of disease progression or death (HR=0.16; P<0.001). Additionally, a higher percentage of patients in the Osimertinib group remained alive and progression-free at 12 months compared to the placebo group (74% versus 22% respectively). Subgroup analyses were conducted to evaluate the consistency of treatment effects across various demographic and clinical factors. The benefits of Osimertinib were observed across all prespecified subgroups, indicating a consistent treatment effect, regardless of patient characteristics. The incidence of new lesions was lower with Osimertinib compared to placebo (22% versus 68%), and this included new brain lesions (8% versus 29%) and new lung lesions (6% versus 29%) respectively. The Objective Response Rate was higher with Osimertinib than with placebo (57% versus 33%). The median Duration of Response was longer with Osimertinib (36.9 months) than with placebo (6.5 months). Interim OS data showed a favorable trend for Osimertinib, although maturity was limited at the time of analysis. Further follow-up will be conducted to assess OS as a secondary endpoint. The adverse event profile of Osimertinib was generally consistent with previous studies. Grade 3 or higher adverse events occurred more frequently in the Osimertinib group, with radiation pneumonitis being the most common. However, no new safety concerns emerged during the trial.

In summary, treatment with Osimertinib resulted in significantly longer Progression Free Survival than placebo in patients with unresectable Stage III EGFR-mutated NSCLC following definitive CRT, and should be considered the new standard of care for this group of patients. Overall, the LAURA study represents a major breakthrough in the treatment of EGFR-mutated Stage III NSCLC, addressing an unmet need for targeted therapies in this setting. Further follow-up will provide additional insights into the long-term efficacy and safety of Osimertinib in this patient population.

Osimertinib after Chemoradiotherapy in Stage III EGFR-Mutated NSCLC. Lu S, Kato T, Dong X, et al. for the LAURA Trial Investigators. N Engl J Med 2024;391:585-597

Late Breaking Abstract – ASCO 2024: Sustained Improvement in Relapse Free Survival with Personalized mRNA Cancer Vaccine plus KEYTRUDA® in Resected High Risk Melanoma

SUMMARY: The American Cancer Society estimates that for 2024, about 100,640 new cases of melanoma of the skin will be diagnosed in the United States and 8,290 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 melanoma. In the KEYNOTE-054 trial, the 5-year Relapse Free Survival (RFS) with adjuvant Pembrolizumab (KEYTRUDA®) was 55.4% versus 38.3% with placebo. In the CHECKMATE-238 trial, the 4-year RFS rate was of 51.7% for Nivolumab (OPDIVO®) versus 41.2% for ipilimumab (YERVOY®). Given the high relapse rates with the present adjuvant melanoma therapies, there is an unmet clinical need.

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.

mRNA-4157 (V940) is a novel messenger RiboNucleic Acid (mRNA)-based individualized neoantigen therapy consisting of a single synthetic mRNA coding for up to 34 neoantigens, that is designed and produced based on the unique mutational signature of the DNA sequence of the patients tumor. Individualized neoantigen therapies are designed to prime the immune system so that a patient can generate a tailored antitumor response specific to their tumor mutation signature. mRNA-4157 (V940) was designed to stimulate an immune response by generating specific T cell responses based on the unique mutational signature of a patients tumor. Early clinical studies demonstrated that combining mRNA-4157 (V940) with Pembrolizumab may potentially provide an additive benefit and enhance T cell-mediated destruction of tumor cells.

KEYNOTE-942 is an ongoing randomized, open-label, Phase IIb trial, designed to evaluate the efficacy and safety of mRNA-4157, an individualized neoantigen therapy, in combination with Pembrolizumab, in patients with completely resected high-risk Stage III/IV cutaneous melanoma. This study included 157 patients who were randomly assigned (2:1) to receive mRNA-4157 in combination with Pembrolizumab (N=107) or Pembrolizumab alone (N=50). The vaccine was administered 1 mg every three weeks for a total of nine doses, and Pembrolizumab was given at 200 mg IV every three weeks for up to 18 cycles (approximately one year). All patients had tumor sample (Formalin Fixed Paraffin Embedded-FFPE) available for Next Generation Sequencing and patients were stratified by disease stage. mRNA-4157 was successfully prepared for more than 99% of patients in the combination arm. The median patient age was 62 years and 84% of patients had Stage IIIC disease. Approximately 64% of patients were PD-L1 positive and 74% had high Tumor Mutational Burden-TMB (10 or more mutations/Mb) in the combination treatment group, whereas 54% were PD-L1 positive and 60% had high TMB in the single agent Pembrolizumab group, respectively. HLA genotyping was performed to explore associations between specific HLA alleles and treatment response. Additionally, subgroup analyses were conducted based on TMB, PD-L1 expression, and circulating tumor DNA (ctDNA) status.

The Primary endpoint was Relapse Free Survival (RFS), defined as the time from first dose of Pembrolizumab until the date of first recurrence (local, regional, or distant metastasis), a new primary melanoma, or death from any cause. Secondary endpoints included Distant Metastasis-Free Survival and Safety. Exploratory endpoints included distribution of TMB expression in baseline tumor samples across study arms and their association with the primary RFS endpoint.

At a median follow up of 23 months for the mRNA-4157/V940 plus Pembrolizumab group, and 24 months for Pembrolizumab alone group, the Relapse Free Survival at 18 months was 78.6% for the immunotherapy combination versus 62.2% for Pembrolizumab alone (HR=0.56; P=0.0266), and this equated to a 44% reduction in the risk of recurrence or death with 2 years of follow-up. mRNA-4157/V940 and Pembrolizumab combination treatment demonstrated an improvement in RFS, irrespective of PD-L1 status and TMB status.

In the recent data presented at ASCO 2024, with an additional year of planned follow-up, at a median of approximately 34.9 months, the combination of mRNA-4157 and Pembrolizumab demonstrated a significant clinically meaningful and durable improvement in RFS, the Primary endpoint of the study, compared to Pembrolizumab alone. The risk of recurrence or death was reduced by 49% (HR=0.51; P=0.019), compared to Pembrolizumab monotherapy. The 2.5-year RFS rate for the combination group was 74.8% compared to 55.6% in the Pembrolizumab alone group. The RFS improvement was observed across subgroups irrespective of TMB and PD-L1 levels.

The combination therapy also showed a meaningful improvement in Distant Metastasis-Free Survival, which was a key Secondary endpoint, compared to Pembrolizumab alone (HR=0.38; P=0.015). This represented a 62% reduction in the risk of developing distant metastases or death compared to Pembrolizumab alone.

While not formally tested as a Primary endpoint, Overall Survival trended favorably with the combination therapy, with a 2.5-Year OS Rate of 96.0% for combination versus 90.2% for Pembrolizumab alone (HR=0.425).

The safety profile of mRNA-4157 in combination with Pembrolizumab was consistent with previous analyses and the common adverse events were fatigue (60.6%), injection site pain (56.7%), and chills (49.0%). Grade 3 or higher adverse events occurred in 25% of patients receiving combination therapy and 18% in the Pembrolizumab alone group. Immune-related adverse events were reported by approximately 37.5% of patients in the combination group and 36% in the Pembrolizumab alone group, with no new safety signals identified.

The KEYNOTE-942 trial demonstrated that mRNA-4157 in combination with Pembrolizumab significantly improved Recurrence-Free Survival and Distant Metastasis-Free Survival in patients with resected high-risk Stage III/IV melanoma, compared to Pembrolizumab alone. These findings suggest a potential benefit across various patient subgroups based on TMB, PD-L1 expression, and ctDNA status. The safety profile was manageable and consistent with expectations for both treatments. Based on these positive results, further investigation in the Phase III INTerpath-001 trial is underway to validate these findings and potentially transform the adjuvant treatment landscape for melanoma patients.

Individualized neoantigen therapy mRNA-4157 (V940) plus pembrolizumab in resected melanoma: 3-year update from the mRNA-4157-P201 (KEYNOTE-942) trial.Weber JS, Khattak MA, Carlino MS, et al. J Clin Oncol 42, 2024 (suppl 17; abstr LBA9512). DOI 10.1200/JCO.2024.42.17_suppl.LBA9512

Late Breaking Abstract – ASCO 2024: Subcutaneous versus Intravenous RYBREVANT® in Refractory EGFR Mutated Advanced NSCLC

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 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer. Approximately 10-15% of Caucasian patients and 35-50% of Asian patients with Adenocarcinomas, harbor activating EGFR mutations and 90% of these mutations are either exon 19 deletions or L858R substitution mutation in exon 21.

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 (LECLAZA®) 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.

Amivantamab given intravenously along with Lazertinib demonstrated antitumor activity in EGFR-mutated advanced NSCLC. PALOMA-3 study evaluated the efficacy, PharmacoKinetics (PK), and safety of a subcutaneous formulation of Amivantamab given along with Lazertinib, compared to intravenous (IV) administration given along with Lazertinib, in patients with EGFR Exon 19 deletion or L858R-mutated advanced NSCLC.

PALOMA-3 is a randomized, controlled Phase III trial in which 418 patients who had disease progression on Osimertinib and platinum-based chemotherapy were randomly assigned 1:1 to receive subcutaneous (SC) or intravenous (IV) Amivantamab, both combined with Lazertinib, with 206 patients (N=206) assigned to the SC arm and 212 patients (N=212) assigned to the IV arm. SC Amivantamab was administered at 1600 mg weekly for the first 4 weeks and then every 2 weeks, while IV Amivantamab was given at the approved dose of 1050 mg. Lazertinib was administered at 240 mg orally daily in both groups. Prophylactic anticoagulation was recommended for the first 4 months. The median age of patients was 61 years, 67% were female, 61% were Asian, patients had received a median of two prior lines of therapy, and 34% had a history of brain metastases. Co-primary pharmacokinetic noninferiority endpoints were trough concentrations (C trough on Cycle 2 Day 1 or Cycle 4 Day 1) and Cycle 2 AUC Day1-Day 15. Secondary endpoints included Objective Response Rate (ORR) and Progression Free Survival (PFS). Overall Survival (OS) was an exploratory endpoint.

At a median follow up of 7 months, the trial met both co-primary PK endpoints. SC Amivantamab demonstrated non-inferiority compared to IV in terms of trough concentrations and AUC, with geometric mean ratios favoring SC administration. SC Amivantamab along with Lazertinib showed a non-inferior ORR (30.1%) compared to IV (32.5%), meeting the predefined noninferiority criteria (RR=0.92; P=0.001). Among confirmed responders, SC administration resulted in a longer median DoR (11.2 months) compared to 8.3 months with IV administration. Although not statistically significant, SC Amivantamab along with Lazertinib showed a favorable trend in PFS (median 6.1 months versus 4.3 months for IV; HR 0.84, P=0.20). Overall Survival was notably longer with SC administration (HR 0.62; P=0.017), with 65% alive at 12 months in the SC arm versus 51% in the IV group.

SC administration significantly reduced Infusion-Related Reactions by 5 fold (13% versus 66% for IV), with no severe reactions leading to hospitalization in the SC arm. Prophylactic anticoagulation reduced Venous Thromboembolism (VTE) risk (9% SC versus 14% IV) and the overall incidence was lower in the SC group, emphasizing safety benefits. Across both treatment groups, VTE incidence was 10% for patients who received prophylactic anticoagulants versus 21% for patients who did not. With regards to patient experience, SC administration took less than 5 minutes, significantly shorter than IV (initial infusion 5 hours), contributing to higher patient satisfaction (85% versus 35% found SC convenient at end of treatment).

It was concluded that the PALOMA-3 trial demonstrated that SC administration of Amivantamab is non-inferior to IV in terms of PK and efficacy endpoints and represents a paradigm shift towards more patient-friendly and effective treatment options for EGFR-mutated NSCLC, with lower rates of Infusion-Related Reactions and VTE.

Subcutaneous amivantamab vs intravenous amivantamab, both in combination with lazertinib, in refractory EGFR-mutated, advanced non-small cell lung cancer (NSCLC): Primary results, including overall survival (OS), from the global, phase 3, randomized controlled PALOMA-3 trial. Leighl NB, Akamatsu H, Lim SM, et al. J Clin Oncol 42, 2024 (suppl 17; abstr LBA8505)

Late Breaking Abstract – ASCO 2024: Long Term Outcomes with LORBRENA® in ALK-Positive Non Small Cell Lung Cancer

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

The discovery of chromosomal rearrangements of the Anaplastic Lymphoma Kinase (ALK) gene in some patients with advanced NSCLC and adenocarcinoma histology, and their sensitivity to ALK inhibitors, paved the way to the development of small-molecule ALK Tyrosine Kinase Inhibitors. It has become clear that appropriate, molecularly targeted therapy for tumors with a molecular abnormality, results in the best outcomes. According to the US Lung Cancer Mutation Consortium (LCMC), two thirds of patients with advanced adenocarcinoma of the lung, have a molecular driver abnormality. The most common oncogenic drivers in patients with advanced adenocarcinoma of the lung are, KRAS in 25%, EGFR in 21% and ALK in 8%, as well as other mutations in BRAF, HER2, AKT1 and fusions involving RET, NTRK and ROS oncogenes. These mutations are mutually exclusive, and the presence of two simultaneous mutations, are rare.

ALK inhibitors include first-generation XALKORI® (Crizotinib) and second-generation ALK inhibitors such as ZYKADIA® (Ceritinib), ALECENSA® (Alectinib) and ALUNBRIG® (Brigatinib). Despite the improved efficacy of second-generation ALK inhibitors, recurrent disease due to drug resistance including CNS disease progression can still develop.

Lorlatinib (LORBRENA®) is a novel third-generation ALK inhibitor that is more potent than second-generation inhibitors, and has the broadest coverage of ALK resistance mutations that have been identified. Lorlatinib crosses the blood-brain barrier and has marked intracranial activity in previously treated patients with baseline CNS disease, including leptomeningeal disease.

The CROWN study is an ongoing, multicenter, global, open-label, randomized Phase III trial, conducted to compare the efficacy and safety of Lorlatinib versus Crizotinib in treatment-naive patients with advanced Stage IIIB/IV or recurrent ALK-positive NSCLC. In this study, 296 eligible patients were randomly assigned 1:1 to receive Lorlatinib 100 mg orally once daily (N=149) versus Crizotinib 250 mg orally twice daily (N=147) in cycles of 28 days. Treatment was continued until disease progression or unacceptable toxicities. Eligible patients were required to have ALK-positive tumors detected by the Ventana ALK (D5F3) CDx assay. Patients with asymptomatic treated or untreated CNS metastases were eligible and had to have at least one extracranial measurable target lesion that had not been previously irradiated. Patients were stratified according to the presence of brain metastases and ethnic group (Asian or non-Asian) and crossover between the treatment groups was not permitted. The Primary end point was Progression Free Survival (PFS) as assessed by Blinded Independent Central Review (BICR). Secondary end points included independently assessed Overall Survival (OS), Objective Response Rate (ORR) and intracranial objective response, time to intracranial progression, Duration of Response, and duration of intracranial response. At a planned interim analysis, treatment with Lorlatinib resulted in statistically significant and clinically meaningful improvement in PFS as assessed by BICR, with a Hazard Ratio of 0.28 (P<0.001), corresponding to a 72% reduction in the risk of disease progression or death. The median PFS was Not Reached in the Lorlatinib arm and was 9.3 months for those treated with Crizotinib. Based on these results, the FDA in 2021, the FDA granted regular approval to Lorlatinib for patients with previously untreated, advanced metastatic NSCLC, whose tumors are ALK-positive.

Given that the median PFS was Not Reached (NR) after 3 years of follow-up, the researchers conducted this post hoc analysis of the Phase III CROWN study, to evaluate the long-term outcomes of Lorlatinib versus Crizotinib at the clinically meaningful landmark follow-up of 5 years, and updated investigator-assessed efficacy outcomes, safety, and biomarker analyses.

With a median follow-up for PFS of 60.2 months for Lorlatinib and 55.1 months for Crizotinib, the median PFS was Not Reached (NR) with Lorlatinib after 5 years and was 9.1 months with Crizotinib (HR=0.19; 95% CI 0.13 to 0.27), The 5-year PFS was 60% and 8% respectively. This represents the longest reported PFS with any molecular targeted therapy in advanced NSCLC and across metastatic solid tumors. The median time to intracranial progression was NR with Lorlatinib and 16.4 months with Crizotinib (HR=0.06; 95% CI, 0.03 to 0.12). New ALK resistance mutations were not detected in circulating tumor DNA collected at the end of Lorlatinib treatment.

The confirmed ORR by investigator assessment was 81% with Lorlatinib and 63% with Crizotinib and the median Duration of Response was NR and 9.2 months respectively. In patients with measurable and/or nonmeasurable baseline brain metastases, intracranial objective response was also greater with Lorlatinib than with Crizotinib (60% versus 11%, respectively) and intracranial complete response was reported in 49% and 5% of patients, respectively. The median duration of intracranial response was NR with Lorlatinib and 12.8 months with Crizotinib.

Treatment related Grade 3-4 adverse events were noted in 66% of patients in the Lorlatinib group and 39% of patients in the Crizotinib group leading to dose reduction in 21% and 13% respectively. However, dose reduction did not impact median PFS or time to intracranial progression in these patients.

In summary, the CROWN study represents a pivotal trial that establishes Lorlatinib as a milestone in ALK-targeted therapy, providing unprecedented Progression Free Survival and intracranial efficacy in treatment-naive patients with advanced ALK-positive NSCLC, setting a new standard in the treatment landscape of this disease. Overall Survival data were not mature at the time of this analysis and continued research into optimal sequencing of ALK inhibitors and exploration of biomarkers are essential to predict treatment response and resistance.

Lorlatinib Versus Crizotinib in Patients With Advanced ALK-Positive Non–Small Cell Lung Cancer: 5-Year Outcomes From the Phase III CROWN Study. Solomon BJ, Liu G, Felip E, et al. J Clin Oncol 42, 2024 (suppl 17; abstr LBA8503). DOI:10.1200/JCO.2024.42.17_suppl.LBA8503

FDA Approves KRAZATI® with ERBITUX® for KRAS G12C-Mutated Colorectal Cancer

SUMMARY: The FDA on June 21, 2024, granted accelerated approval to Adagrasib (KRAZATI®) plus Cetuximab (ERBITUX®) for adults with KRAS G12C-mutated locally advanced or metastatic Colorectal Cancer (CRC), as determined by an FDA-approved test, who have received prior treatment with Fluoropyrimidine, Oxaliplatin, and Irinotecan-based chemotherapy.

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 152,810 new cases of colorectal cancer will be diagnosed in the United States in 2024 and about 53,010 patients will die of the disease. The lifetime risk of developing colorectal cancer is about 1 in 23.

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

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

Adagrasib (KRAZATI®) is a potent, orally available, small molecule covalent inhibitor of KRAS G12C. This drug irreversibly and selectively binds KRAS G12C in its inactive, GDP-bound state. Unlike Sotorasib (LUMAKRAS®)), which is also a selective covalent inhibitor of KRAS G12C, Adagrasib has a longer drug half-life of 23 hours, as compared to 5 hours for Sotorasib, has dose-dependent extended exposure, and can penetrate the CNS. Unlike the efficacy of single-agent KRAS G12C inhibitors in Non Small Cell Lung Cancer with KRAS G12C mutation, KRAS G12C inhibition alone has limited activity in patients with colorectal cancer. This has been attributed to upstream reactivation of the Epidermal Growth Factor Receptor (EGFR) pathway resulting in treatment-induced resistance, following selective inhibition of KRAS G12C. However, dual KRAS G12C and EGFR blockade can overcome treatment resistance in patients with colorectal cancer with KRAS G12C mutation.

Cetuximab (ERBITUX®) is an anti-EGFR monoclonal antibody that is indicated for the treatment of RAS wild-type metastatic colorectal cancer, either as monotherapy or in combination with chemotherapy. Combining Cetuximab with Adagrasib may overcome treatment resistance and enhance the inhibition of KRAS-dependent signaling and improve outcomes.

The present FDA approval was based on the ongoing KRYSTAL-1, multicenter, expansion cohort Phase 1-2 trial, in which the use of Adagrasib as monotherapy or in combination with Cetuximab was evaluated in patients with previously treated metastatic colorectal cancer with mutant KRAS G12C. Eligible patients had locally advanced or metastatic KRAS G12C-mutated colorectal cancer, and had previous treatment with Fluoropyrimidine, Oxaliplatin, and Irinotecan-based chemotherapy, and a VEGF inhibitor, if eligible. These patients were heavily pretreated, having received a median of three prior lines of therapy, and their disease had shown resistance to previous treatments. Patients received Adagrasib 600 mg orally twice daily along with Cetuximab 500 mg/m2 IV every two weeks, or 400 mg/m2 IV as initial dose followed by 250 mg/m2 IV weekly. Tumor assessments were performed every 6 weeks. Treatment was continued until disease progression or unacceptable toxicity, Adagrasib discontinuation required Cetuximab discontinuation, however patients could continue Adagrasib if Cetuximab was discontinued. The median patient age was 59 years old, and 51% were women and both treatment groups were well balanced. The Primary efficacy endpoint of the study was the confirmed Overall Response Rate (ORR), assessed by Blinded Independent Central Review (BICR). Secondary endpoints included Duration of Response (DOR), Progression Free Survival (PFS), Overall Survival (OS), and Safety. Efficacy was assessed in 94 (N=94) enrolled patients.

The study met its Primary endpoint and the ORR was 34%. All responses were Partial Responses (PR), indicating a reduction in tumor burden in responding patients. The median Duration of Response was 5.8 months, with 31% of responders experiencing a Duration of Response of at least 6 months. The most common adverse reactions were rash, nausea, vomiting, diarrhea, fatigue, musculoskeletal pain, hepatotoxicity, anemia, headache, dry skin, decreased appetite, abdominal pain, constipation, edema, cough, and peripheral neuropathy.

In conclusion, the KRYSTAL-1 trial has demonstrated that Adagrasib in combination with Cetuximab shows promising clinical activity and a manageable safety profile in heavily pretreated patients with metastatic CRC harboring the KRAS G12C mutation. These findings highlight a potential new treatment option for patients who have limited therapeutic alternatives and underscore the evolving landscape of precision medicine in oncology, particularly in targeting specific mutations that drive tumor growth and survival.

https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-adagrasib-cetuximab-kras-g12c-mutated-colorectal-cancer.

Late Breaking Abstract – ASCO 2024: KRAZATI® Superior to Docetaxel in KRAS G12C Mutated Non Small Cell Lung Cancer

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 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers.

The KRAS (kirsten rat sarcoma viral oncogene homologue) proto-oncogene encodes a protein that is a member of the small GTPase super family. The KRAS gene provides instructions for making the KRAS protein, which is a part of a signaling pathway known as the RAS/MAPK pathway. By relaying signals from outside the cell to the cell nucleus, the protein instructs the cell to grow, divide and differentiate. The KRAS protein is a GTPase, and converts GTP into GDP. To transmit signals, the KRAS protein must be turned on by binding to a molecule of GTP. When GTP is converted to GDP, the KRAS protein is turned off or inactivated, and when the KRAS protein is bound to GDP, it does not relay signals to the cell nucleus. The KRAS gene is in the Ras family of oncogenes, which also includes two other genes, HRAS and NRAS. When mutated, oncogenes have the potential to change normal cells cancerous.

KRAS is the most frequently mutated oncogene in human cancers and are often associated with resistance to targeted therapies and poor outcomes. The KRAS G12C mutation occurs in approximately 25% of Non Small Cell Lung Cancers (NSCLC) and in 3-5% of colorectal cancers and other solid cancers. KRAS G12C is one of the most prevalent driver mutations in NSCLC and accounts for a greater number of patients than those with ALK, ROS1, RET, and TRK 1/2/3 mutations combined. KRAS G12C cancers are genomically more heterogeneous and occur more frequently in current or former smokers, and are likely to be more complex genomically than EGFR mutant or ALK rearranged cancers. G12C is a single point mutation with a Glycine-to-Cysteine substitution at codon 12. This substitution favors the activated state of KRAS, resulting in a predominantly GTP-bound KRAS oncoprotein, amplifying signaling pathways that lead to oncogenesis.

Adagrasib (KRAZATI®) is a potent, orally available, small molecule covalent inhibitor of KRAS G12C. This drug irreversibly and selectively binds KRAS G12C in its inactive, GDP-bound state. Unlike Sotorasib (LUMAKRAS®), which is also a selective covalent inhibitor of KRAS G12C, Adagrasib has a longer drug half-life of 23 hours, as compared to 5 hours for Sotorasib, has dose-dependent extended exposure, and can penetrate the CNS. Approximately, 27-42% of patients with NSCLC harboring KRAS G12C mutations have CNS metastases, with poor outcomes. The U.S. FDA granted accelerated approval for Adagrasib as a targeted treatment for patients with KRASG12C-mutated locally advanced or metastatic NSCLC who have received at least one prior systemic therapy in December 2022.

KRYSTAL-12 trial is a pivotal, open-label, multicenter, randomized, Phase III study designed to compare Adagrasib against standard-of-care chemotherapy (Docetaxel) in patients with KRASG12C-mutated NSCLC who had received prior platinum-based chemotherapy concurrently or sequentially with anti-PD-(L)1 therapy. In this study, 453 patients were randomized 2:1 to receive either Adagrasib 600 mg orally twice a day (N=301) or Docetaxel 75 mg/m2 IV every 3 weeks (N=152). Importantly, patients in the Docetaxel arm had the option to crossover to Adagrasib upon confirmed disease progression. Patients were stratified by region (non-Asia Pacific versus Asia Pacific) and by whether they received concurrent or sequential chemoimmunotherapy. Patients with stable brain metastases were allowed. Both treatment groups were well balanced. The median age was 64.5 years, 95% of patients had adenocarcinoma histology with metastatic disease and approximately 75% of patients were former smokers and previously received concurrent chemoimmunotherapy. The Primary endpoint of the study was Progression Free Survival (PFS) as assessed by Blinded Independent Central Review (BICR). Secondary endpoints included Overall Survival (OS), Overall Response Rate (ORR), Duration of Response (DOR), Safety assessments and Patient-Reported Outcomes. At the time of this analysis, 29% of patients had crossed over from Docetaxel treatment to receive Adagrasib.

With a median follow-up of 9.4 months, the trial met its Primary endpoint, with Adagrasib demonstrating a significant improvement in PFS over Docetaxel (median PFS 5.5 versus 3.8 months; HR=0.58, P<0.0001). The benefit of Adagrasib over Docetaxel was maintained across key subgroups. The ORR was also significantly higher with Adagrasib compared with Docetaxel (32% versus 9%; Odds Ratio 4.68; P<0.0001). The median Duration of Response was 8.3 months versus 5.4 months respectively, and responses were sustained at least 6 months in 64% and 39% of patients, respectively. Among those patients with CNS metastases at baseline, intracranial responses were observed in 24% of patients receiving Adagrasib and 11% of patients receiving Docetaxel, with intracranial Disease Control Rate of 82% and 56%, respectively. There was also a significant benefit in the Patient-Reported Outcomes of median time to deterioration. There were no new safety signals noted with Adagrasib and the safety data was consistent with the known safety profile. Grade 3 or more treatment-related adverse events occurred in 47% of patients treated with Adagrasib and 45.7% of patients treated with Docetaxel and treatment discontinuation rates were 7.7% versus 14.3%, respectively.

In summary, the KRYSTAL-12 trial confirmed Adagrasib as a superior treatment option compared to Docetaxel in patients with previously treated KRASG12C-mutated locally advanced or metastatic NSCLC. Adagrasib significantly improved Progression Free Survival, Overall Response Rate, and Duration of Response, with a notable impact on intracranial disease control rates. Its safety profile was manageable, aligning with expectations from earlier studies. These findings underscore the potential of Adagrasib in this patient population and highlight ongoing research efforts to further optimize treatment strategies in this challenging patient population.

KRYSTAL-12: Phase 3 study of adagrasib versus docetaxel in patients with previously treated advanced/metastatic non-small cell lung cancer (NSCLC) harboring a KRASG12C mutation. Mok TSK, Yao W, Duruisseaux M, et al. J Clin Oncol. 2024;42(suppl 17):LBA8509.

Late Breaking Abstract – ASCO 2024: ENHERTU® Improves PFS in HR-Positive, HER2-Low and HER-Ultralow Metastatic 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. It is estimated that in the US, approximately 310,720 new cases of female breast cancer will be diagnosed in 2024, and about 42,250 individuals will die of the disease, largely due to metastatic recurrence.

The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of invasive breast cancers overexpress HER2/neu oncogene, which is a negative predictor of outcomes without systemic therapy. Patients with high levels of HER2 expression (IHC 3+ or 2+/FISH+) are classified as HER2-positive. 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. Tumors that are not classified as HER2-positive are classified as HER2-negative. Despite being classified as HER2-negative, majority these tumors still have some level of HER2 expression.

About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor (HR)-positive/HER2-negative breast cancer is the most frequently diagnosed molecular subtype. It is estimated that approximately 60-65% of HR-positive/HER2-negative breast cancers are HER2-low and potentially an additional 25% may be HER2-ultralow. These patients are often treated with single agent endocrine therapy, endocrine therapy in combination with CDK4/6 inhibitor, or chemotherapy. Resistance to hormonal therapy occurs in a majority of the patients and there is therefore an unmet need for agents with novel mechanisms of action. Further, there are no targeted therapies specifically approved for patients with HER2-low or HER2-ultralow expression, prior to chemotherapy.

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

DESTINY-Breast06 is a global, randomized, open-label Phase III trial evaluating the efficacy and safety of ENHERTU® versus chemotherapy in patients with HR-positive, HER2-low, or HER2-ultralow advanced or metastatic breast cancer. This study enrolled 866 patients (N=713 for HER2-low and N=153 for HER2-ultralow). HER2-low was defined as IHC 1+ or 2+ or FISH negative and HER2-ultralow was defined as IHC 0 with membrane staining. Patients were randomized 1:1 to receive ENHERTU® 5.4 mg/kg every 3 weeks (N=436) or physicians choice of chemotherapy which included Capecitabine, Paclitaxel, or nab-Paclitaxel (N=430). Patients in the trial had no prior chemotherapy for advanced or metastatic disease and received at least two lines of prior endocrine therapy in the metastatic setting. Patients were also eligible if they had received one prior line of endocrine therapy combined with a CDK4/6 inhibitor in the metastatic setting and experienced disease progression within six months of starting 1st-line treatment, or received endocrine therapy as an adjuvant treatment and experienced disease recurrence within 24 months. Patients were stratified based on prior CDK4/6 inhibitor use, HER2 expression and prior taxane use in the non-metastatic setting. Patients in the trial had received a median of two prior lines of endocrine therapy. In the overall trial population, 14.9% of patients in the ENHERTU® group and 19.2% in the chemotherapy group had received one prior line of endocrine therapy. No patients had received prior chemotherapy for metastatic disease. The Primary endpoint was Progression Free Survival (PFS) in the HER2-low patient population as measured by Blinded Independent Central Review (BICR). Key Secondary endpoints included Progression Free Survival (PFS) in the overall trial population (HER2-low and HER2-ultralow), Overall survival (OS) in the HER2-low patient population, Objective Response Rate (ORR), Duration of response (DOR) and Safety. The median duration of follow-up was 18.2 months.

In the primary analysis of this study, results showed that in the HER2-low expression patients, ENHERTU® reduced the risk of disease progression or death by 38%, with a median PFS was 13.2 months in the ENHERTU® group, compared to 8.1 months for chemotherapy (HR=0.62; P<0.0001). For the overall trial population (HER2-low and HER2-ultralow), the median PFS results were similar and the median PFS was 13.2 months for ENHERTU® versus 8.1 months for chemotherapy (HR=0.63; P<0.0001). ENHERTU® reduced the risk of disease progression or death by 37% compared to chemotherapy.

A prespecified exploratory analysis showed that the improvement in PFS was consistent between patients with HER2-low and HER2-ultralow expression. In patients with HER2-ultralow expression, ENHERTU® reduced the risk of disease progression or death by 22% compared to chemotherapy, with a median PFS of 13.2 months versus 8.3 months, respectively (HR=0.78).

The Objective Response Rate (ORR) in HER2-Low Population was 56.5% for ENHERTU® compared to 32.2% for chemotherapy, in the Overall Trial Population was 57.3% for ENHERTU® versus 31.2% for chemotherapy, and in the HER2-Ultralow Subgroup was 61.8% for ENHERTU® versus 26.3% for chemotherapy. The median duration of response across these three groups was 14.3 months.

The safety profile of ENHERTU® was consistent with previous breast cancer clinical trials and no new safety concerns identified. The most common Grade 3 or higher treatment-related adverse events occurring in 5% or more of patients treated with ENHERTU® were neutropenia (20.7%) and anemia (5.8%). Interstitial Lung Disease (ILD), adjudicated as drug-related by an independent committee, occurred in 11.3% of patients treated with ENHERTU®. The majority of ILD events were low grade.

The results from the DESTINY-Breast06 trial underscore the significant clinical benefits of ENHERTU® in improving PFS and ORR in patients with HR-positive, HER2-low, and HER2-ultralow metastatic breast cancer, offering a promising alternative to standard chemotherapy. These findings highlight the potential of ENHERTU® to become a new standard of care for this patient population, pending further investigation and regulatory approval. The detailed positive outcomes underscore the clinical benefits and reinforce the promise of ENHERTU® in treating this challenging cancer subtype.

Trastuzumab deruxtecan (T-DXd) vs physician’s choice of chemotherapy (TPC) in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-low or HER2-ultralow metastatic breast cancer (mBC) with prior endocrine therapy (ET): Primary results from DESTINY-Breast06 (DB-06). Curigliano G, Hu X, Dent RA, et al. J Clin Oncol. 2024;42(suppl 17):LBA1000. doi:10.1200/JCO.2024.42.17_suppl.LBA1000.

Late Breaking Abstract – ASCO 2024: TAGRISSO® after Chemoradiotherapy in Stage III EGFR Mutated Non-Small Cell Lung Cancer

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 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Approximately one third of all patients with NSCLC have Stage III, locally advanced disease at the time of initial presentation and 60 to 90% of these patients have unresectable disease. These patients are treated with concurrent chemoradiotherapy (CRT) followed by consolidation therapy with Durvalumab (IMFINZI®) in patients without progression, as this regimen confers an Overall Survival advantage, and is considered the standard of care (PACIFIC trial).

EGFR (Epidermal Growth Factor Receptor) mutations are found in up to one third of patients with unresectable Stage III NSCLC. There are currently no approved targeted treatments for patients with unresectable Stage III EGFR-mutated NSCLC. The current standard of care, which includes consolidation therapy with Durvalumab, may not offer clear benefits to this subset of patients with EGFR mutations.

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

LAURA was a global, randomized, double-blind, placebo-controlled, multicenter Phase III trial conducted to assess the efficacy and safety of Osimertinib in patients with unresectable Stage III NSCLC harboring EGFR mutations (EGFR exon 19 deletion or exon 21 L858R mutation). The trial enrolled patients who had not experienced disease progression during or after definitive platinum-based chemoradiotherapy (CRT). A total of 216 patients who had undergone CRT were randomly assigned 2:1 to receive Osimertinib 80 mg orally once daily (N=143) or placebo once per day (N=73). Treatment was continued until Blinded Independent Central Review (BICR)–assessed disease progression, unacceptable toxicity, or other discontinuation criteria were met. Upon disease progression, patients in the placebo arm were permitted to receive Osimertinib, allowing for crossover therapy. Stratification factors included method of CRT (concurrent versus sequential) and disease Stage (IIIA versus IIIB/C). Both treatment groups were well balanced. The median patient age was 63 years, approximately 60% of participants were female, 83% were Asian, 69% had never smoked and 85% had Stage IIIA and B disease. Majority of patients received concurrent CRT rather than sequential CRT. The Primary end point was Progression Free Survival (PFS) as assessed by BICR. Key Secondary end points included Overall Survival (OS), survival without progression of CNS disease (CNS Progression Free Survival), Objective Response Rate (ORR), Duration of Response, Quality of Life, and Safety.

Treatment with Osimertinib resulted in significant PFS improvement compared to placebo. The median PFS was 39.1 months in the Osimertinib group versus 5.6 months in the placebo group, representing an 84% reduction in the risk of disease progression or death (HR=0.16; P<0.001). Additionally, a higher percentage of patients in the Osimertinib group remained alive and progression-free at 12 months compared to the placebo group (74% versus 22% respectively). Subgroup analyses were conducted to evaluate the consistency of treatment effects across various demographic and clinical factors. The benefits of Osimertinib were observed across all prespecified subgroups, indicating a consistent treatment effect, regardless of patient characteristics. The incidence of new lesions was lower with Osimertinib compared to placebo (22% versus 68%), and this included new brain lesions (8% versus 29%) and new lung lesions (6% versus 29%) respectively. The Objective Response Rate was higher with Osimertinib than with placebo (57% versus 33%). The median Duration of Response was longer with Osimertinib (36.9 months) than with placebo (6.5 months). Interim OS data showed a favorable trend for Osimertinib, although maturity was limited at the time of analysis. Further follow-up will be conducted to assess OS as a secondary endpoint. The adverse event profile of Osimertinib was generally consistent with previous studies. Grade 3 or higher adverse events occurred more frequently in the Osimertinib group, with radiation pneumonitis being the most common. However, no new safety concerns emerged during the trial.

In summary, treatment with Osimertinib resulted in significantly longer Progression Free Survival than placebo in patients with unresectable Stage III EGFR-mutated NSCLC following definitive CRT, and should be considered the new standard of care for this group of patients. Overall, the LAURA study represents a major breakthrough in the treatment of EGFR-mutated Stage III NSCLC, addressing an unmet need for targeted therapies in this setting. Further follow-up will provide additional insights into the long-term efficacy and safety of Osimertinib in this patient population.

Osimertinib after definitive chemoradiotherapy (CRT) in patients (pts) with unresectable stage  III epidermal growth factor receptor-mutated (EGFRm) NSCLC: primary results of the phase 3 LAURA study. Ramalingam SS, Kato T, Dong X, et al. J Clin Oncol. 2024;42(suppl 17):LBA4.