Fecal Transplantation and Immunotherapy: a Winning Combination to Beat Melanoma?

For the first time in Canada, a team from the CHUM Research Centre (CRCHUM) will study the efficacy of a therapy combining intestinal microbiota and immunotherapy to treat melanoma. The goal? To show that altering intestinal microbiota through fecal transplantation could increase the life expectancy of cancer patients.

Supported by a $1.5M grant awarded to Dr. Bertrand Routy by the Canadian Cancer Society, an initial phase l study begins at the CRCHUM’s Unit for Innovative Therapies for patients with metastatic melanoma. Led by Dr. Routy and Dr. Rahima Jamal, the study aims to modify these patients’ intestinal microbiota through fecal transplantation. This treatment will be combined with immunotherapy.

In this unit, headed by Dr. Jamal, phase I and II clinical trials allow patients who have run out of therapeutic options to access promising treatments, mainly in oncology.

In an initial study, 20 patients with advanced melanoma will participate in the research project during the first year in order to demonstrate to Health Canada the efficacy and non-toxicity of the treatment. Following that, a second study will be launched, for which 120 patients with melanoma skin cancer or non-small-cell lung cancer will be recruited over a four-year period. They will all be distributed into two groups to compare the results of two treatments: fecal microbiota transplantation, also known as stool transplantation, combined with immunotherapy, or immunotherapy alone.

Imagining the Anti-Cancer Arsenal of the Future

Cancer patients are aware that their immune system is weakening. In recent years, new drugs called immune checkpoint inhibitors (ICI) have given them hope by revolutionizing therapies targeting melanoma and lung cancer. Simply put, this type of immunotherapy activates the immune system to kill cancer cells.

Despite these advances, long-lasting responses to the treatment occur in a minority of patients and most cancers reappear.

But there is light at the end of the tunnel. As recent scientific breakthroughs at the CRCHUM have shown, the composition of the intestinal microbiota, made up of billions of bacteria, can affect our immune system and a patient’s response to ICI therapy.

In fact, Dr. Routy’s team has helped show that intestinal microbiota affect the clinical response of lung and kidney cancer patients treated by ICI.

To this end, the new study being conducted by Dr. Routy and his team (specialists in immuno-oncology, pathology and bioinformatics) will clarify why certain patients do not respond to ICI therapy and will evaluate whether fecal transplantation, combined with ICI, will improve clinical results in this type of patient.

Further Information

• This research will be conducted in collaboration with teams working under Saman Maleki and Dr. John Lenehan (London Health Sciences Centre), as well as those under Dr. Wilson Miller (Jewish General Hospital). The CRCHUM’s melanoma biobank will also play a role.
• The CRCHUM’s Unit for Innovative Therapies is at the forefront of early clinical research. Its goal: to offer innovative cancer treatments to patients who have run out of therapeutic options. This 15-bed unit relies on a team of 23 people dedicated to early clinical studies (phases l and ll), collaborating with more than 60 investigators.
• In 2020, 8,000 Canadians were diagnosed with melanoma and 1,300 Canadians died of it (source: Canadian Cancer Society).
• In 2020, 29,800 Canadians were diagnosed with lung cancer and 21,200 died of it (source: Canadian Cancer Society). In 2018, the World Health Organization indicated that lung cancer accounted for nearly 2.1 million deaths.