The FDA's approval of lazertinib (Lazcluze) in combination with the bispecific antibody amivantamab (Rybrevant) has introduced a new first-line treatment option for patients with EGFR-mutant non-small cell lung cancer (NSCLC). This development, based on the phase III MARIPOSA trial, offers an alternative to osimertinib (Tagrisso), either as monotherapy or with pemetrexed and platinum-based chemotherapy.
MARIPOSA Trial Results
The MARIPOSA trial demonstrated that lazertinib plus amivantamab reduced the risk of progression or death by 30% compared to osimertinib alone. The median progression-free survival (PFS) was 23.7 months with the combination therapy versus 16.6 months with osimertinib. A secondary analysis further indicated improved median PFS in patients with high-risk disease biomarkers, such as TP53 co-mutation, and those with circulating tumor (ct)DNA clearance. The combination also showed benefits for patients with brain and liver metastases.
Clinical Considerations and Adoption
Despite the promising results, the adoption of lazertinib/amivantamab varies among oncologists. Some, like Timothy F. Burns, MD, PhD, of the UPMC Hillman Cancer Center, are less inclined to use the combination due to the lack of an amivantamab-alone arm in the MARIPOSA study and the higher rates of toxicities associated with intravenous amivantamab, such as rash, peripheral edema, and blood clots when combined with lazertinib. Oral therapies are often preferred by patients.
Conversely, Danny Nguyen, MD, of City of Hope Orange County Lennar Foundation Cancer Center, notes that the majority of his patients favor the combination therapy after discussing the potential benefits and risks. This highlights the importance of shared decision-making in treatment selection.
Addressing Adverse Events
Efforts are underway to mitigate the adverse events associated with amivantamab. A study is exploring prophylactic dermatologic management for patients receiving first-line lazertinib/amivantamab. Additionally, a subcutaneous formulation of amivantamab is being investigated to reduce side effects and the time commitment of intravenous infusions. The phase III PALOMA-3 study showed that subcutaneous amivantamab, combined with lazertinib in refractory EGFR-mutant NSCLC, was noninferior to the intravenous formulation and significantly reduced infusion-related reactions.
Unanswered Questions and Future Research
The optimal sequencing of treatments remains unclear, as there has been no crossover in the trials. The MARIPOSA trial's trend toward better overall survival is tempered by the fact that patients initially treated with osimertinib did not receive amivantamab. Research is needed to determine whether amivantamab should be administered first or second-line. A phase II study by Helena Yu, MD, at Memorial Sloan Kettering Cancer Center, is exploring ctDNA clearance after initial osimertinib treatment to guide subsequent therapy with or without chemotherapy.