Moderna-Merck Cancer Therapy Collaboration Delivers Positive Phase 3 Readout

Moderna Inc.'s (NASDAQ:MRNA) and Merck & Co.'s (NYSE:MRK) mRNA cancer therapy, intismeran autogene (mRNA-4157/V940), has delivered its first positive Phase 3 readout. The collaboration between the two companies dates back to a June 2016 agreement, amended in 2018, where Merck paid Moderna a $200 million upfront fee.

Under their genuine 50/50 partnership, both companies split all costs and any profits or losses equally worldwide, with Moderna handling manufacturing and process development while Merck leads clinical trials. This arrangement was triggered when Merck exercised its option in September 2022, paying an additional $250 million fee.

The positive Phase 3 readout is a significant milestone for both companies, with Merck's shares up 10.69% to $149.41, pushing its market cap to approximately $368.6 billion. This represents one of Merck's biggest single-day dollar moves given its size.

Interestingly, while Moderna's stock surge is dominating the tape, Merck's stake in this data may be more important for long-term investors. The company's Keytruda patent cliff looms in December 2028, with related patents potentially extending exclusivity to 2029 and EU protection lasting until 2031.

Merck's defense against this patent expiration includes reformulation, aggressive M&A diversification away from Keytruda entirely, and next-generation combinations that keep pembrolizumab clinically relevant even after patent loss. Intismeran autogene is the flagship example of this third track, diversifying Merck's revenue away from Keytruda while extending its commercial life.