RE:RE:TIGIT class of checkpoint inhibitors fails with Keytruda Merck & Co. has failed its phase 2 TIGIT clinical trial, revealing that neither combination featuring its anti-TIGIT (T cell immunoglobulin and ITIM domain) antibody vibostolimab as monotherapy or in combination with pembrolizumab. improved progression-free or overall survival (PFS/OS).
The study enrolled patients with metastatic non-small cell lung cancer (NSCLC) with progressive disease after receiving immunotherapy and platinum-doublet chemotherapy. In March, Merck revealed that the combination of vibostolimab and its anti-PD-1 immunotherapy Keytruda was numerically less effective than docetaxel in terms of PFS, the primary endpoint.
Merck dropped the two-drug combination, (anti-TIGIT vibostolimab in combination with pembrolizumab) which it was testing in an open-label arm, and continued to give people vibostolimab, Keytruda and docetaxel in a blinded cohort. The drugmaker shared data on all three arms at the 2023 European Society of Medical Oncology Immuno-Oncology Annual Congress.
More results suggest vibostolimab plus Keytruda is ineffective in the targeted, later-line NSCLC population. PFS in patients who received the two-drug cocktail was 2.7 months, compared to 3.2 months in the docetaxel control arm. OS was 7.5 months for the combo and 8.8 months for the control.
The blinded cohort of patients who received all three drugs fared better, although the improvement over docetaxel alone fell short of statistical significance. PFS in the three-drug cohort was 5.6 months and OS was 10.2 months.
The study is part of a much broader program, which could still show vibostolimab is effective outside of the hard-to-treat population it targeted.
https://www.fiercebiotech.com/biotech/merck-co-digs-tigit-fail-sharing-survival-data-phase-2-lung-cancer-trial
https://pubmed.ncbi.nlm.nih.gov/34800678/