Logos of Moderna and Merck [AFP]
Logos of Moderna and Merck [AFP]

A personalized mRNA cancer vaccine jointly developed by US pharmaceutical companies Moderna and Merck has met its primary endpoints in a late-stage Phase 3 clinical trial, demonstrating meaningful suppression of cancer recurrence and metastasis in high-risk melanoma patients.

The two companies announced Wednesday that the Phase 3 trial of intismeran autogene cevumeran, their personalized mRNA cancer treatment, used in combination with Merck's immunotherapy drug Keytruda had produced positive results. It marks the first time a personalized neoantigen therapy and an mRNA-based cancer treatment have achieved positive outcomes in a Phase 3 clinical trial.

The trial enrolled 1,137 high-risk patients who had undergone surgery to remove melanoma. Participants were divided into two groups: one receiving intismeran autogene cevumeran in combination with Keytruda, and the other receiving Keytruda alone.

Patients in the combination group showed a statistically significant and clinically meaningful improvement in recurrence-free survival — the length of time after treatment during which cancer does not return — compared with those receiving Keytruda alone.

Intismeran autogene cevumeran works by analyzing each patient's tumor tissue to identify the unique mutational "fingerprint" of their cancer cells, then designing a synthetic mRNA to trigger an immune response targeting those specific mutations.

The treatment encodes up to 34 neoantigens per patient in a synthetic mRNA. Once administered, it prompts the immune system to recognize those antigens and mount a T-cell response that attacks cancer cells.

Researchers said the results could represent a new paradigm in precision immunotherapy — designing treatments tailored to the specific tumor characteristics of individual patients.

The Wall Street Journal said the development opens the door to a new treatment capable of preventing recurrence and extending survival in patients with melanoma, a deadly form of skin cancer.

Moderna said it hopes to receive regulatory approval for commercial sale by 2027.

News of the trial's success sent Moderna's share price surging roughly 132 percent on the New York Stock Exchange as of noon Wednesday.

The results are seen as giving Moderna — which has struggled since the peak of its COVID-19 vaccine business — a foothold in the anticancer drug market, estimated at $240 billion.

Merck also benefited, with its shares rising about 11 percent at the same time, as the results are expected to further enhance the therapeutic value of its flagship cancer drug Keytruda.


mokiya@heraldcorp.com