Merck and Kelun's ADC Shows Promise in First-Line Lung Cancer Treatment

Merck & Co. and its partner Kelun-Biotech have reported significant progress in the development of a potential first-line treatment for non-small cell lung cancer (NSCLC). The combination of Kelun's TROP2-targeting antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT) and Merck's Keytruda has shown promising results in a late-stage clinical trial, potentially reshaping the landscape of lung cancer therapy.

Phase 3 Trial Success

The OptiTROP-Lung05 study, conducted in China, demonstrated that the combination of sac-TMT and Keytruda led to a statistically significant and clinically meaningful improvement in progression-free survival compared to Keytruda alone in patients with previously untreated PD-L1-positive NSCLC. This marks the first time an ADC combined with an immune checkpoint inhibitor has achieved its primary endpoint in a Phase 3 trial for first-line NSCLC treatment.

Kelun-Biotech plans to discuss these results with Chinese regulators for a potential approval application. The study's success has raised investor optimism, with Jefferies analyst Akash Tewari suggesting that sac-TMT could become a "$10 billion plus opportunity" for Merck.

Global Development and Competition

While the Chinese trial results are promising, the global pharmaceutical landscape remains competitive. Merck is currently testing sac-TMT in 15 global Phase 3 clinical trials across six tumor types, including endometrial, breast, and lung cancers. The company's aggressive development strategy is supported by a recent $700 million funding deal with Blackstone Life Sciences.

Other major players are also advancing TROP2-targeting therapies. AstraZeneca and Daiichi Sankyo's Datroway is being evaluated in combination with chemotherapy and Imfinzi for first-line NSCLC treatment. Gilead Sciences is investigating Trodelvy plus Keytruda in the first-line setting for PD-L1-positive NSCLC.

Market Implications and Future Outlook

The success of sac-TMT could have significant implications for Merck's portfolio, potentially offsetting future revenue losses from Keytruda's patent expiration. However, the drug's path to market dominance is not without challenges. The OptiTROP-Lung05 trial's design, which compared the combination to Keytruda monotherapy rather than the more common Keytruda-chemotherapy combination, limits its immediate applicability to global treatment paradigms.

As the TROP2 ADC field becomes increasingly competitive, the coming years will likely see a series of critical trial readouts that could reshape the treatment landscape for NSCLC and other cancer types. The pharmaceutical industry will be watching closely as these therapies progress through late-stage development and regulatory review.