Experimental cancer vaccine shows promise in late-stage trial

Merck and Moderna’s experimental personalized cancer vaccine has delivered positive results in its first phase three trial, the companies announced Wednesday, moving the treatment closer to potential regulatory approval

The mRNA vaccine, combined with Merck’s Keytruda, met the main goals of a study involving more than 1,100 patients with high-risk or advanced melanoma whose tumors had been surgically removed, according to CNBC.

The combination significantly extended the time patients remained free of melanoma compared with Keytruda alone and lowered the risk of the cancer spreading elsewhere.

The companies plan to present the findings at an upcoming medical meeting. The trial will continue to evaluate overall survival, while the timing of US approval applications remains unclear.

The results could establish the combination as a new option for melanoma, which represents about 1% of skin cancers but causes most skin cancer deaths. Most melanoma recurrences occur within two to three years of initial treatment.

Melanoma patients are “stuck having to deal with the new gravity of that diagnosis and then undergo uncomfortable treatments like surgery, and after that, they’re worried about their cancer coming back,” said Dr. Jane Healy, Merck’s head of oncology early development.

She described the results as “very exciting,” citing a “clinically meaningful improvement” over Keytruda, the standard melanoma treatment. Patients also tolerated the therapy well, with side effects similar to those associated with routine vaccines.

The vaccine is designed to target mutations unique to each patient’s tumor rather than using a one-size-fits-all approach. The goal is to train the immune system to recognize and destroy those cancer markers, while Keytruda strengthens the immune response.

“We think (the results are) very meaningful for patients with this disease and really the potential of what it can mean for other patients for cancer in future trials with this particular new class of therapy,” she said.