The FDA has given Fast Track designation to pelareorep (Reolysin), an intravenous oncolytic virus therapy, for second-line treatment of patients with KRAS-mutant, microsatellite-stable metastatic colorectal cancer. The therapy is used in combination with standard treatment, bevacizumab plus FOLFIRI.
The decision is based on Phase 1 trial data showing strong improvements compared with historical standard care. Patients receiving pelareorep had higher response rates and lived longer without disease progression, as well as longer overall survival.
Researchers also found that pelareorep boosts immune activity by increasing T cells that specifically target KRAS-mutant tumors, helping the immune system better recognize and attack the cancer. A Phase 2 randomized study is set to begin in March, with early results expected by the end of 2026.