Dostarlimab

Key findings of the study-

• The clinical trial comprised a group of 18 patients, all of them were battling rectal cancer at the Memorial Sloan Kettering Cancer Center in Manhattan, US.
• In all patients, rectal cancer was locally advanced, which means the tumours had spread within the rectum and in some cases, to the lymph nodes, but not to other organs.
• The trial used a monoclonal antibody called dostarlimab every three weeks for six months for the treatment of a particular kind of stage two or three rectal cancer. 
• Dostarlimab works by “unmasking” cancer cells, which in turn helps the immune system identify and destroy them.
• This has been described as a “first time in history” kind of result in cancer treatment with the disease simply vanishing in patients after the experimental treatment.
• The trial showed that immunotherapy alone – without any chemotherapy, radiotherapy, or surgery could completely cure the patients with a particular kind of rectal cancer called ‘mismatch repair deficient’ cancer”.
• ‘Mismatch repair deficient’ cancer is most common among colorectal, gastrointestinal, and endometrial cancers. 
• Patients suffering from this condition lack the genes to correct typos in the DNA that occur naturally while cells make copies.
• The immunotherapy belongs to a category called PD1 blockades that are now recommended for the treatment of such cancers rather than chemotherapy or radiotherapy. 
• PD1 is a type of protein that regulates certain functions of the immune system, including by suppressing T cell activity, and PD1 blockade therapy looks to release the T cells from this suppression.
• The study was sponsored by the drug company GlaxoSmithKline of the US.