HOPES IN THE FIGHT AGAINST CANCER - VACCINE REDUCES THE RISK OFRECURRENCE OR DEATHFROM MELANOMA BY 42% - HOW IT WORKS - Filenews 23/10
Pharmaceutical companies Moderna and Merck have announced encouraging results in the fight against cancer, as a personalized mRNA technology vaccine, combined with immunotherapy, seems to significantly reduce the risk of melanoma recurrence. According to clinical trial results, the risk of recurrence or death was reduced by 42%, while the risk of developing distant metastases or death was reduced by 38%.
The findings, which come from more than 1,100 patients, raise expectations for a new generation of cancer therapies, designed based on the specific genetic characteristics of each patient's tumour.
This is the first successful end-stage clinical trial to show that this technology can significantly enhance the effectiveness of an already established immunotherapy. The detailed results of the study, with about two years of follow-up data, are expected to be presented on Saturday, October 24 at the European Society of Medical Oncology (ESMO) conference in Madrid.
How does the vaccine designed individually for each patient work?
The experimental vaccine, known as intismeran autogene, uses the same messenger RNA (mRNA) technology that Moderna's Covid-19 vaccines were based on.
The important difference is that, instead of training the immune system to deal with a virus, it directs it to recognize and attack cancer cells.
Each dose is prepared specifically for the patient who is about to receive it. After surgical removal of the tumour, scientists genetically analyze a sample of the tumour tissue, identifying the mutations that are most likely to cause a strong immune response.
Based on this information, a personalized vaccine is designed, which helps the immune system recognize the specific characteristics of cancer cells and fight any residual disease.
"This personalized cancer vaccine is a special type of therapy that enhances the body's immune response solely against the cancer cells present," explained oncologist Michael Postow, who was involved in the therapeutic follow-up of patients in the study.
As he added, this approach offers a much more targeted strengthening of the immune system against the particular tumour of each patient.
The combination with Keytruda and the test results
The vaccine was administered in combination with Merck's Keytruda (pebrolizumab), one of the most widely used immunotherapies internationally.
This drug, first approved in 2014, works by releasing the immune response against cancer cells, which previously could escape the body's defenses.
The phase 3 clinical trial, called INTerpath-001, involved 1,137 patients with high-risk melanoma whose tumours had been surgically removed.
The study compared the effectiveness of the combination of vaccine and Keytruda with the administration of Keytruda alone.
After a median follow-up of 24.6 months, the combination achieved a 42% reduction in the relative risk of recurrence or death and a 38% reduction in the relative risk of remote metastasis or death.
82.2% of patients who received the combination remained alive without recurrence of the disease over two years, compared with 70% of those who received Keytruda alone.
These numbers are a comparison of the two treatment approaches and do not mean that the vaccine cures cancer permanently or that it reduces overall mortality by 42% on its own.
Moderna and Merck had already announced in August that the study had achieved its main goals, without then releasing the detailed data.
The case of 59-year-old Beth who returned to the life she loves
Among the patients who participated in the trial was 59-year-old Beth Rizik, who was diagnosed in December 2023 with stage IIIC melanoma.
At this stage, the cancer had spread to the lymph nodes, significantly increasing the risk of it recurring after surgical removal.
Michael Postow explained that, despite the removal of the tumour, many patients in this category face a high risk of recurrence.
"We would like surgery in itself to be a definitive cure. But we know from many studies that patients in this condition have a high probability of developing the cancer again, either in other lymph nodes or in organs such as bones, liver, lungs or brain," he said.
For this reason, adjuvant treatment is usually administered after surgery, with the aim of preventing the recurrence of the disease.
Rizik joined the personalized vaccine study and completed her treatment last spring, symbolically ringing the bell at her treatment center.
Today she has returned to the daily life she loves, travelling with her husband.
"We are now in full retirement," she said, explaining that their children have grown up, but they do not yet have grandchildren, which allows them to travel without special restrictions.
"We can just get up and leave. And that's what we're doing," she said.
She expressed the hope that the new therapeutic approach will become available to other patients, without its cost being a prohibitive obstacle.
Pharmaceutical companies typically don't announce the price of a new treatment before it's regulatory approval.
Why Moderna shares fell despite positive results
Despite the optimism of the scientific community, the reaction of the financial markets was negative.
On Thursday (22/10), Moderna's stock fell about 18%, while Merck's stock recorded a drop of 1,8%.
The development was attributed to the high expectations of investors, who expected even greater efficiency from the combination.
Analysts, including RBC Capital Markets' Trung Hun, pointed out that the results were slightly lower than those of a previous, smaller clinical trial.
However, he estimated that the US Food and Drug Administration (FDA) is likely to approve the treatment in 2027.
For Moderna, the success of the personalized vaccine is of particular strategic importance.
The company experienced tremendous growth thanks to its Covid-19 vaccines, but then faced a significant drop in demand as the acute phase of the pandemic subsided.
The expansion of mRNA technology in oncology is now considered one of the most important possibilities for its future development.
When the success of the study was announced in August, Moderna's stock price more than doubled, then continuing its upward trajectory.
Despite the recent decline, its profits since the start of 2026 were still exceeding 500%, according to analyst Miles Meinter of William Blair, who called the findings "extraordinary data".
The Next Step for Personalized Cancer Vaccines
The importance of the study is not limited to the treatment of melanoma.
Moderna and Merck are exploring the possibility of applying the same technology to other forms of cancer, with the aim of creating treatments that will recognize the specific mutations of each tumour.
The next crucial step is the evaluation of the data by regulators in order to consider the approval of the vaccine in combination with immunotherapy.
Despite the encouraging results, the treatment remains experimental and further data are needed on long-term efficacy, safety and whether it could benefit patients with other cancers.
For the researchers, however, the findings are an important step towards a different treatment model: instead of a one-size-fits-all cancer treatment, the development of personalized vaccines that harness the genetic characteristics of each patient's cancer.
