Moderna, Merck cancer vaccine posts promising late-stage trial results

Merck and Moderna’s experimental personalized cancer vaccine has achieved a key goal in a late-stage melanoma trial, strengthening its prospects as a future treatment.

Shares of both companies soared on the news. Moderna shares jumped 177% by yesterday’s close following the announcement, while Merck rose 13%.

The Phase 3 study involved more than 1,100 patients with high-risk or advanced melanoma after surgery removed all detectable tumors.

The treatment could give melanoma patients more time without a recurrence. In trials, pairing the personalized mRNA vaccine with Merck’s Keytruda reduced the risk of the cancer returning or spreading after surgery.

But because the vaccine is tailored to each patient, it’s costly to make.

Scientists used a biopsy and blood sample after surgery to build a genetic profile of the melanoma. They then identified unique mutations that could trigger an immune response and used them to create an mRNA vaccine paired with Keytruda. The process takes about six weeks.

Earlier results showed the combination reduced the risk of melanoma recurrence or death by 49% compared with Keytruda alone.

Merck and Moderna are now testing the technology in other cancers, including non-small cell lung, bladder and kidney cancers. They expect to begin discussions with regulators about approval and safety in the coming months.

The findings have not yet been independently reviewed.

Big win for mRNA
Health Secretary Robert F. Kennedy Jr. ended 22 government-funded mRNA vaccine contracts worth $500 million last year, arguing for broader vaccine platforms instead.