FDA grants Breakthrough Therapy designation to intismeran with Keytruda for high-risk melanoma

Moderna/Intismeran autogene (mRNA-4157/V940)

The FDA granted Breakthrough Therapy designation to Moderna and Merck's personalised mRNA cancer vaccine intismeran (mRNA-4157/V940) with Keytruda after surgery for high-risk melanoma. It rests on the 157-patient Phase 2b KEYNOTE-942 trial, the first randomised efficacy result for an mRNA cancer treatment.

• Breakthrough designation speeds development and FDA review; reflects unmet need and promising efficacy signal.
• KEYNOTE-942 enrolled 157 patients with stage IIB–IV melanoma; intismeran tailored to each tumor's mutations.
• 18-month RFS: 79% (combination) vs 62% (Keytruda alone); HR 0.561 just missed p<0.05 but clinically significant.
• First randomised mRNA cancer vaccine efficacy data; personalized approach aligns tumor-specific immunity.