An anti-cancer vaccine soon?

What is immunotherapy?

Our immune system is a jewel of complex and competent machinery. Throughout life, it single-handedly fights viruses, bacteria and other pathogens that we encounter on a daily basis. But faced with cancerous cells, this complex army sometimes finds itself powerless. Taking on the appearance of healthy cells, tumors trick the soldiers of our immune system. Oncology research has for several years tried to solve this challenge by trying to help our body fight cancer cells itself. The vaccine uses parts of cancer cells as antigens to trick the immune system into attacking them. This is the principle of immunotherapy, a new personalized therapeutic weapon that is revolutionizing cancer treatment.

The Lake Geneva basin stands out as one of the key places for cancer research. Among the various lines of work: the development of personalized anti-cancer vaccines. The UNIL-CHUV Department of Oncology (University of Lausanne – Center hospitalier universitaire vaudois), with its Lausanne branch of the Ludwig institute for cancer research, has just started two clinical trials under the leadership of Prof. Lana Kandalaft, head of department of the Center of experimental therapies (ETC) of the department in question.

How does a cancer vaccine work?

With a therapeutic aim and personalized according to the patient and his cancer, the vaccine consists in educating the immune system to help it fight once morest specific targets, specific to the tumour. This is the principle of immunotherapy. “Cancer develops differently in each individual,” explains Lana Kandalaft. For the same type of tumor, cancer cells can reveal very different mutations from one person to another, hence the importance of ultra-personalized treatment.”

To develop this vaccine, the CTE teams must first identify the specific antigens of the patient’s cancer cells. Then, in a second step, reintroduce them into the body to train it to recognize these targets and fight them. The anti-cancer vaccine is therefore not intended for the general population, but for people already affected by cancer.

Clinical tests

The two clinical trials conducted by the CTE are for pancreatic cancer and lung cancer. A third project will begin shortly for ovarian cancer. “These cancers are very difficult to treat, partly because of the physiology of so-called “cold” tumours, that is to say which are not recognized by T* cells, underlines Lana Kandalaft. The vaccine makes it possible to change the environment of the tumors to transform them into so-called “hot” tumors, which are more easily identifiable.

Via a state-of-the-art technical platform and from either a sample of antigens transformed into small proteins (peptides), or ground material from the tumor itself taken from the patient, Lana Kandalaft’s team manages to cultivate in the laboratory specific and safe “radar” to target cancer cells. Once reintroduced into the patient’s body, these will form T cells to recognize and attack the tumor.

On paper, things look easy. But the effectiveness of immunotherapy is conditioned by different parameters and many lines of thought are being pursued by research teams. “The great difficulty, adds Lana Kandalaft, is to be able to identify the best antigen for each tumor: is it a peptide, a combination of different peptides or a ground material from the tumor itself that will be the most effective in combating it? We are also wondering regarding the combination of the vaccine with other cancer treatments or even regarding the ideal time to perform the injection.

Avoid relapses

After surgery and chemotherapy, once in remission, patients might benefit from this “tailor-made” vaccine, in order to prevent a recurrence of the disease. “The hope of these trials currently being carried out on certain types of particularly aggressive cancers is to succeed in reducing this risk of relapse and thus prolonging the life expectancy of patients”, explains the researcher. With a 5-year survival rate stagnating at 26% for lung cancer and 13% for pancreatic cancer, this therapeutic perspective is promising.

But if preliminary results have been able to show the efficacy and safety of the vaccine, its development nevertheless comes up once morest certain limits. The sinews of war, as often: time and money. The development of a targeted vaccine requires expensive technologies and requires human time. The ETC laboratory manages to produce around four vaccines per month, but has set itself the goal of doubling this performance in the short term. “Today, the tools have been improved, we know the immune system better and better, we know how to make the treatment and we understand how it works, concludes Lana Kandalaft with optimism. We have never been closer to bringing these vaccines to market.”

A bridge between the laboratory and the bedside

A vast research platform integrated into the Vaud University Hospital Center (CHUV) since 2014, the Center for Experimental Therapies (CTE), set up and directed by Prof. Lana Kandalaft, operates as a bridge between, on the one hand, research in laboratory around personalized cellular therapies and, on the other hand, the establishment of concrete and rapid therapeutic prospects for patients.

With 180 employees, covering 750 m²making it one of the largest academic T cell manufacturing facilities in continental Europe, the CTE has established itself as a global reference in the transition of research programs towards new treatments and care techniques, from the laboratory to the patient.

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* Or T lymphocytes, “soldiers” of the immune system.

Published in Le Matin Dimanche on 05/15/2022.