Merck & Co. and partner Sichuan Kelun-Biotech Biopharmaceutical said their combination therapy achieved a 70 percent response rate in a late-stage trial for advanced lung cancer, a significant improvement over Keytruda alone.
"The combination significantly improved progression-free survival... compared to those treated with Keytruda alone," Kelun-Biotech said in a statement Thursday.
The trial, which enrolled more than 400 previously untreated patients in China with advanced non-small cell lung cancer (NSCLC) and PD-L1 expression, met its primary endpoint. It tested the antibody-drug conjugate sacituzumab tirumotecan (sac-TMT) plus Merck’s blockbuster Keytruda against Keytruda as a standalone treatment. The combination arm's objective response rate of approximately 70 percent far outpaced the 42 percent for the Keytruda monotherapy group.
The results bolster Keytruda's position as a backbone of cancer therapy and validate the strategy of combining it with other drug classes like antibody-drug conjugates (ADCs). For Kelun-Biotech, the positive data is a major milestone that could lead to a significant drug approval in partnership with a global pharmaceutical giant, validating the Chinese firm's discovery platform.
A New Combination Approach
Sac-TMT is an ADC, a type of targeted therapy that functions like a guided missile to deliver chemotherapy directly to cancer cells by binding to a protein called TROP2. This trial's success demonstrates the potential of pairing the targeted cell-killing of an ADC with the broad immune system activation of a PD-1 inhibitor like Keytruda. While the treatment's safety profile was consistent with the known effects of both drugs, serious side effects, including low white blood cell counts and anemia, were more common in the combination group.
The positive data comes on the same day that Merck and Moderna announced positive five-year data for their personalized cancer vaccine combined with Keytruda in melanoma. Together, the results underscore Merck's strategy of building upon Keytruda's success by using it as a foundational therapy in combination with a wide range of other treatments, including ADCs and mRNA vaccines. NSCLC is the most common type of lung cancer, accounting for about 87 percent of all cases in the United States, according to the American Cancer Society, representing a massive market for effective new treatments.
The success of the sac-TMT combination provides a new blueprint for treating PD-L1 positive NSCLC, potentially establishing a new standard of care that pairs a TROP2-targeting ADC with a PD-1 inhibitor. Investors will now await regulatory filings in China and look for further data on overall survival to confirm the drug's blockbuster potential.
This article is for informational purposes only and does not constitute investment advice.
