Merck (MRK) Unveils Initial Clinical Data for Bispecific Antibody 'MK-2010,' Entering the Non-Small Cell Lung Cancer Market
MK-2010: A New Drug to Prepare for the Expiration of Keytruda's Monopoly
Merck & Co. (MRK) has finally disclosed the initial Phase 1/2 clinical data for MK-2010 (LM-299), a PD-1/VEGF bispecific antibody licensed from LaNova Medicines, at the American Association for Cancer Research (AACR 2026). This announcement marks a significant step in Merck's strategy to overcome the patent cliff of its blockbuster immunotherapy drug, Keytruda, and secure a next-generation immunotherapy backbone. The data, presented on patients with treatment-naive non-small cell lung cancer (NSCLC), provides early indicators of safety and efficacy, signaling a potential shift in the landscape of cancer treatment.
Efficacy in the First-Line Treatment Group and Analysis of Data by Dosage Group
In the Phase 1/2 clinical trial conducted in China, 11 treatment-naive, PD-L1-positive NSCLC patients were administered 20 mg/kg of the drug every three weeks, resulting in an unconfirmed objective response rate (ORR) of 55%. The 30 mg/kg dosage group, used as a control, showed a response rate of 44% in 9 patients. Notably, the lower dosage group demonstrated superior efficacy and a more favorable safety profile. This is comparable to the 50% response rate observed in the Phase 3 trial of Ivonescimab from Summit Therapeutics (SMMT) and Akeso, a competitor.
Safety Concerns and the Challenge of Optimizing Dosage
The well-known adverse effects of VEGF inhibitors, such as proteinuria and bleeding, were partially controlled through the bispecific antibody platform, but remain areas of concern. In the 20 mg/kg group, no Grade 3 or higher severe proteinuria or bleeding adverse events were observed. However, the higher dosage group (30 mg/kg) experienced Grade 4 bleeding and even a Grade 5 event (death) due to hemoptysis, raising safety concerns. This safety data provides strong evidence that Merck should adopt a 20 mg/kg dosage as the standard in the design of the Phase 3 trial, which will be crucial in improving the quality of life and medication adherence for patients.
A More Cautious Approach Compared to Competitors and the Underlying Strategy
Unlike competitors such as Sanofi, BioNTech (BNTX), Bristol Myers Squibb (BMS), and Pfizer (PFE), which are aggressively expanding global Phase 3 trials in the PD-1/VEGF field, Merck is taking a more cautious approach, delaying the announcement of a specific Phase 3 roadmap. Industry experts believe that Merck is prioritizing the allocation of significant research and development (R&D) resources to sac-TMT, a Trop2-targeted antibody-drug conjugate (ADC) co-developed with Kelun-Biotech, which is currently in 17 Phase 3 trials. This approach reflects Merck's strategy to maximize the value of its limited pipeline resources through portfolio diversification and to prepare for a well-designed clinical trial as a latecomer.
Merck's Phase 1/2 clinical results demonstrate the efficacy and potential for controlling adverse effects of MK-2010, which is expected to become a key pipeline asset in the global NSCLC market (approximately $30 billion annually) after the expiration of Keytruda's patent. In the short term, Merck's prompt entry into a global Phase 3 trial is crucial to narrow the clinical gap with strong competitors such as Summit Therapeutics' Ivonescimab and Pfizer's PF-08634404. In the medium to long term, the 55% unconfirmed ORR achieved in the 20 mg/kg dosage group and the management of Grade 3 or higher adverse events, such as proteinuria (17%) and bleeding (23%), could serve as the foundation for next-generation combination therapies. Oncologists and investors are closely watching whether Merck can leverage the $300 million technology transfer to maximize the synergy with its ADC pipeline, sac-TMT, and maintain its market dominance in the immunotherapy field.