Pfizer reported mixed topline results from a late-stage lung cancer trial of sigvotatug vedotin, triggering a 3% share drop and a five-day losing streak. The FDA approved Ibrance for HR+ HER2+ metastatic breast cancer after the PATINA trial showed a 24% reduction in progression risk.
Pfizer’s late-stage trial of sigvotatug vedotin returned mixed topline results, failing to meet key efficacy endpoints while showing some disease control in a subset of patients. The experiment was part of Pfizer’s 2023 Seagen acquisition and aimed to expand its oncology portfolio into antibody-drug conjugates.
Following the trial announcement, shares fell 3% on Wednesday, marking a fifth consecutive daily decline as investors weighed uncertainty around Pfizer’s cancer pipeline. Social media highlighted concerns over Pfizer’s recent acquisitions, including the Metsera obesity drug purchase.
The FDA granted approval for Ibrance as maintenance therapy in HR+ HER2+ metastatic breast cancer, based on the PATINA trial showing a 24% reduction in progression risk and median progression-free survival extended to 44 months. This represents the first CDK4/6 inhibitor approval regardless of HER2 status.
The contrasting trial disappointment and Ibrance approval could prompt Pfizer to reassess resource allocation across its oncology assets and integration of recent acquisitions. Analysts will monitor upcoming data readouts and commercialization plans to gauge long-term revenue impacts.
