Pfizer announced on Monday that its experimental lung cancer drug sigvotatug vedotin did not demonstrate a significant survival benefit compared to chemotherapy in a late-stage clinical trial. The study focused on adults with locally advanced, unresectable, or metastatic non-squamous non-small cell lung cancer who had previously undergone other treatments.

The trial evaluated overall survival—the primary endpoint—and found no statistically meaningful improvement for patients receiving sigvotatug vedotin over those treated with the chemotherapy agent docetaxel. This outcome represents a setback for Pfizer, which acquired the drug through its $43 billion purchase of Seagen.

The results underscore ongoing challenges in developing new effective therapies for patients with advanced lung cancer, particularly in cases where prior treatment options have been exhausted. Pfizer did not disclose further details about secondary endpoints or plans for additional studies on sigvotatug vedotin.

Industry analysts note that while the drug’s failure to improve survival is disappointing, Pfizer continues to invest in a broad portfolio of oncology treatments. The company emphasized its commitment to advancing cancer research despite the trial’s outcome.