Thread by @cspramesh

Cancer vanishes from every patient’s body in drug trial “miraculously”; Shocked doctors’ say ‘First time in history’ financialexpress.com/healthcare/new…

What miracle are we talking about?

A drug called dostarlimab, an anti–PD-1 monoclonal antibody (immunotherapy), was given every 3 weeks for 6 months in patients with a subgroup of patients with rectal cancer (stage II or III, mismatch repair–deficient or MMR-deficient). (2/9)

What is the buzz about?

Of the patients given the treatment, and evaluated, all of them had complete disappearance of tumor after 6 months of treatment. Now, this is remarkable, and is the reason why there is a lot of excitement in the oncology community about the results (3/9)

This is certainly exciting, and should encourage all of us treating cancer (and more importantly, our patients). However, to call this a miracle cure which will impact the way we treat cancer globally is premature, and even fanciful. Why? (4/9)

First, the study (which was phase 2) was done in just 12 patients. To consider something a miracle cure, you need much larger numbers of patients being treated, being followed up for a much longer time, and results analyzed. Preferably in a large phase 3 randomized trial (5/9)

Second, MMR-deficient rectal cancers account for <10% of all rectal cancers - this subgroup of patients was selected because they are exquisitely sensitive to immunotherapy. Which means that the results are applicable to a small proportion of all patients with rectal cancer (6/9)

Finally, the cost of the treatment is not trivial - overall treatment costs of 9 doses of the drug (which were given during the study) is expected to range anywhere from Rs 50,00,000 to 1,00,00,000 (100,000 USD), which puts it out of reach for most patients in LMICs. (7/9)

To summarize, this is certainly an exciting study and the treatment strategy has promise, but it is probably premature to conclude that this is a miracle cure and practice-changing. Hopefully, future studies will confirm the benefit seen, but more importantly (8/9)

If the drug is seen to be beneficial in future studies, the cost needs to come down to make it affordable to the vast majority of patients with cancer - let us not forget that 70% of all cancers are expected to occur in low- & middle- income countries #GlobalOncology. (9/9)