Moderna mRNA-based drug cut the risk of recurrence or death when combined with immunotherapy Keytruda

Melanoma is the deadliest form of skin cancer. The United States National Cancer Institute estimates there were more than 100,000 new cases last year, with a five-year survival rate of about 95%. That rate plummets to about 35% when melanoma has spread to other parts of the body. Photo / Getty Images

An experimental drug custom-made to target the genetic mutations of individual tumours showed promise in treating aggressive skin cancer, according to new results from a clinical trial announced today.

The personalised cancer drug is based on the same technology as the leading coronavirus vaccines that helped end the pandemic: sending instructions to the immune system using doses of messenger RNA.

While people received the same vaccine against a common enemy in the case of coronavirus, scientists are using a personalised approach against cancer based on individual gene mutations.

In combination with an approved immunotherapy, the mRNA drug cut the risk of recurrence or death nearly in half after five years compared with melanoma patients who got only the immunotherapy, drugmaker Moderna said.

Moderna is developing the drug, called intismeran autogene, in partnership with Merck, which makes Keytruda, the immunotherapy used in the trial.

“Today’s results highlight the potential of a prolonged benefit of the intismeran autogene and Keytruda combination,” Kyle Holen, a Moderna senior vice-president, said in a statement.

The ongoing clinical trial is evaluating the combination in 157 patients with melanoma that has spread after having the cancer surgically removed.

Participants receive either the experimental treatment or Keytruda alone for about a year.

The results were virtually identical with an earlier analysis published after three years of patient data, which showed the combination reduced the risk of recurrence or death by 49%.

Moderna said today that the safety of intismeran “remains consistent” with its previous reports, which have noted that the number of serious reactions were comparable to patients who received only Keytruda.

The most commonly reported side effects related to intismeran were fatigue, pain at the site of injection, and chills, the drugmakers disclosed in December 2023.

Tailored to individuals

Intismeran is tailored to individual patients, a process that begins by analysing the DNA of a tumour to identify its unique mutations.

The therapy then uses mRNA to deliver instructions to the body’s immune cells to help them recognise and attack the cancer cells based on their genetic signature. Keytruda, given by infusion, helps keep the body’s immune cells active in finding and killing cancer cells.

Melanoma is the deadliest form of skin cancer.

The United States National Cancer Institute estimates there were more than 100,000 new cases last year, with a five-year survival rate of about 95%. That rate plummets to about 35% when melanoma has spread to other parts of the body, as is the case for some participants in the clinical trial.

Moderna and Merck are running a larger clinical trial evaluating the intismeran-Keytruda combination, with financial analysts expecting results later this year.

Myles Minter, a William Blair analyst, wrote in a note to clients that intismeran showed an “impressive effect” over taking Keytruda alone, calling it a “signal of durable tumour control” but cautioning that it is hard to draw conclusions until the drugmakers present the full data from the trial.

Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.