Massive Victory for Humankind: A Drug that Could Treat Cancer

Recently, there has been a massive development in the field of oncology with Dostarlimab, a drug administered to 18 rectal cancer patients in a small clinical trial for six months. The results were to everyone’s amazements as the cancerous tumour disappeared in all the participating patients. Dostarlimab is a medication that contains laboratory-made proteins that act as replacement antigens in the human body. During the trial, the medicine was administered to all the 18 cancer patients, and as a result of this therapy, the cancer was completely cleared in all of them. The participating cancer patients were selected on the basis of different diagnostic examinations like, endoscopy, MRI scans, or positron emission tomography (PET) scans. 

Backdrop

The June 2022 edition of The New England Journal of Medicine, featured an article that talked about a complete remission of rectal cancer among 18 people. The first rectal cancer patient to undergo the process was Sascha Roth. The clinical trial began in 2019. Rectal cancer in the participating patients has been eradicated using immunotherapy in every incident, without any need for conventional treatments such as radiation, operation, or chemotherapy, and none of the patients' cancers has resurfaced in up to two years. The team to make this breakthrough included Dr Luis Diaz, Avery Holmes, Dr Andrea Cercek, and Nisha Varughese. 

The article was published by Dr Luis A. Diaz Jr. from Memorial Sloan Kettering (MSK) Cancer Centre. The drug Dostarlimab is manufactured by GlaxoSmithKline. Immunotherapy is a type of treatment that uses body's immune system to detect and kill tumour cells. According to MSK Cancer Centre, the research focused on a subgroup of rectal cancer patients who had a recessive mutation in their tumour. This type of rectal cancer also referred to as "mismatch repair-deficient" (MMRD) colorectal cancer, has a dismal prognosis when treated with regular chemotherapy. According to the organisation, the goal of the experiment was to see if immunotherapy itself could cure rectal cancer which had not progressed to other tissues.

Working of Immunotherapy

Dostarlimab is referred to as a "checkpoint inhibitor". As per MSK, it essentially "emits the brakes" on an immune cell, allowing it to identify and fight cancer cells. MMRD cells, which have so many mutations, appear especially weird when the brakes are removed from immune cells. As a result, the immune cells launch a considerably more powerful attack. 

The participating cancer patients had Stage 2 or 3 rectal tumours and were sensitive to immunotherapy. The checkpoint antagonist Dostarlimab (Jemperli) was injected intravenously every three weeks for six months in the patients. Throughout the process, the researchers used scanning, visualisation techniques such as endoscopy, and other technologies to keep tabs on the tumours' progress.

Way Forward

The results so far are impressive, however, it is unclear whether the findings of this tiny trial at MSK Cancer Centre will be applicable to a larger group or not. Future trials are seeking heterogeneity in age, concomitant illnesses, and tumour size to provide more information about whether other cancer patients might benefit from immunotherapy. According to the MSK researchers, the clinical study is still enrolling participants and is growing. They are also looking at individuals with gastrointestinal (stomach), prostatic, and pancreatic cancers to see if the same treatment can help them beat other tumours.