(Reuters) -Moderna and its partner Merck said on Wednesday that they had begun enrolling patients in a late-stage study testing their personalized mRNA-based skin cancer vaccine in combination with the immunotherapy Keytruda.
Data from a mid-stage study in 157 patients had shown that the vaccine combination cut the risk of recurrence or death by 44% in patients with melanoma, the most deadly form of skin cancer, when compared with Keytruda alone.
More than 1,000 patients from over 25 countries are expected to be included in the current trial, with the first patients being enrolled in Australia.
The companies are testing the vaccine in melanoma patients whose tumors were surgically removed before being treated with either the drug-vaccine combination or Keytruda alone.
The vaccine is tailored for each patient to generate T-cells, a key part of the body's immune response, based on the specific mutational signature of a tumor.
Merck's Keytruda is a so-called checkpoint inhibitor designed to disable a protein called programmed death 1, or PD-1, that helps cancer to evade the immune system.
BioNTech SE (NASDAQ:BNTX) and Gritstone Bio are also working on competing cancer vaccines based on the mRNA technology.
Scientists have been chasing the dream of vaccines to treat cancer for decades with few successes. According to industry experts, mRNA vaccines, which can be produced in as little as eight weeks, paired with drugs that rev up the immune system may lead to a new generation of cancer therapies.
The late-stage trial's main goal is to measure the amount of time patients live without the cancer returning when treated with the combination, compared to treatment with Keytruda alone.
The duration of the study would depend on when that occurs, the companies said.