NEW YORK – Merck said on Monday that it will no longer develop its anti-TIGIT antibody vibostolimab based on its failure to show survival benefit in various non-small cell lung cancer trials.
Merck had been evaluating vibostolimab with its checkpoint inhibitor Keytruda (pembrolizumab) in PD-L1-positive NSCLC patients in the Phase III KeyVibe-003 and KeyVibe-007 trials. It had also been recruiting patients to a third trial involving vibostolimab, KeyVibe-006. The drugmaker will cease all three trials.
In KeyVibe-003, Merck was pitting vibostolimab plus Keytruda against Keytruda alone in first-line advanced PD-L1-expressing NSCLC. The primary endpoint was overall survival in patients with PD-L1 expression in at least 50 percent of cells.
In KeyVibe-007, Merck was evaluating vibostolimab plus Keytruda and chemotherapy versus Keytruda and chemotherapy alone in a similar patient population. The primary endpoint was overall survival in patients whose tumors expressed PD-L1 in at least 1 percent of cells.
Lastly, in the KeyVibe-006 trial, Merck had planned to evaluate vibostolimab, Keytruda, chemotherapy, and radiation followed by vibostolimab and Keytruda versus chemotherapy and radiation followed by AstraZeneca's Imfinzi (durvalumab) in patients with stage III NSCLC. The primary endpoint was progression-free survival and overall survival among patents whose tumors expressed PD-L1 in at least 1 percent of cells.
Merck also said on Monday that it is discontinuing development of its anti-LAG-3 antibody favezelimab, which it was evaluating in a Phase III trial as a treatment for advanced classical Hodgkin lymphoma patients.
According to Merck, the discontinuations are based on preplanned analyses, in which the agents met the criteria for futility. "Following a careful analysis of the data, the decision has been made to discontinue development of these candidates to prioritize other ongoing programs," Marjorie Green, Merck's senior VP and head of oncology global clinical development, said in a statement.
The drugmaker said that it plans to share the data from the discontinued Phase III trials with the scientific community. It also said that it is in the process of informing the investigators in these trials about the discontinuation and advising patients to speak with their doctors about their next steps and treatment options.