Moderna and drugmaker Merck have started a late-stage study to evaluate their experimental mRNA-based cancer vaccine in combination with cancer therapy Keytruda, the companies said on Wednesday.

The companies will study the safety and efficacy of the vaccine-Keytruda combination in patients with a type of skin cancer, compared to Keytruda alone.

Global recruitment for the trial has begun, with the first patients being enrolled in Australia, the companies said in a joint release.

Shares of Moderna rose 1% in premarket trading.