A personalised mRNA cancer vaccine has delivered positive results in a Phase 3 melanoma trial, marking an important advance in efforts to use the immune system to prevent cancer from returning after treatment.
The experimental therapy, developed by Moderna and Merck, reduced the risk of melanoma recurring or spreading when used alongside Keytruda, Merck’s widely used cancer immunotherapy.
The result is significant because it is the first positive Phase 3 trial of an individualised mRNA-based cancer therapy. It also strengthens the case for using mRNA technology beyond infectious-disease vaccines and into oncology.
Investors reacted strongly to the announcement. Moderna shares surged after the results were released, reflecting expectations that the technology could eventually open a much larger commercial market if it succeeds in other cancers.
How the treatment works
The therapy, known as intismeran autogene, is designed individually for each patient.
Doctors analyse mutations in a patient’s tumour, then use that information to create an mRNA treatment that teaches the immune system to recognise and attack cancer cells carrying those mutations.
That makes it fundamentally different from conventional vaccines, which are produced in standard formulations for large populations.
The Phase 3 INTerpath-001 trial enrolled 1,137 patients with high-risk Stage IIB to IV melanoma whose tumours had already been surgically removed.
Patients received either intismeran with Keytruda or Keytruda alone.
The combination produced statistically significant improvements in recurrence-free survival and in the period before the cancer spread to other parts of the body.
The companies also said no new safety concerns emerged.
Detailed Phase 3 data have not yet been released, and overall survival results are still being evaluated. That means it is too early to conclude whether the treatment ultimately helps patients live longer.
It is also important not to describe the therapy as a cancer cure. It remains experimental and has not yet received regulatory approval.
Earlier results raised expectations
The late-stage findings build on strong results from an earlier Phase 2b trial.
After five years, patients who received intismeran with Keytruda had a 49% lower risk of cancer recurrence or death compared with patients treated with Keytruda alone.
The combination also reduced the risk of distant metastasis or death by 59%.
Those results encouraged both companies to move the treatment into larger studies.
Business Elites Africa has previously examined how cancer vaccines and immunotherapies are changing cancer treatment.
The opportunity goes beyond melanoma
Melanoma may be the first major test, but the commercial opportunity is broader.
Moderna and Merck are studying the same personalised mRNA approach in lung, bladder, kidney and other cancers. Nine Phase 2 and Phase 3 trials are underway across different tumour types.
That wider pipeline helps explain the market reaction.
Barclays estimates that melanoma alone could generate about $3 billion in annual sales by 2035, according to Reuters.
If the technology also works in larger cancer categories, the potential market would be considerably bigger.
For Moderna, the result is particularly important.
The company has been trying to prove that the mRNA platform it used successfully for COVID-19 vaccines can also become a long-term treatment platform for diseases such as cancer.
A successful oncology product would diversify its business and reduce its dependence on respiratory vaccines.
Access may be the bigger challenge
Even if regulators approve the treatment, access will remain difficult in lower-income markets.
The therapy requires tumour sequencing, individual vaccine design, specialised manufacturing and treatment alongside advanced immunotherapy.
That makes it far more complex than producing and distributing a conventional vaccine.
For countries such as Nigeria, where access to advanced cancer treatment is already limited, the challenge will go beyond regulatory approval.
Diagnostic capacity, treatment infrastructure and cost will determine whether personalised cancer vaccines can reach patients at scale.
Moderna and Merck are expected to present the full Phase 3 findings at a medical conference and discuss the results with regulators.
