Last Friday’s news about the failed Phase III clinical trial with immunotherapy Keytruda in combination with Incyte’s cancer therapy epacadostat not only has wiped $4m from the US biotech’s capitalization over few hours, but has also risen much concern among scholars and scientists and in the finance world about the actual potential of this class of cancer drugs.
The first immunotherapy ever was launched in 2014 and Keytruda’s sales volume has only increased since then, reaching $10bn in 2017 thanks to Keytruda and BMS’ Opdivo. However, what has always raised most concern among investors and scientists is that immunotherapies are effective only in 20-30% of cases, while they fail in most cases.
The idea of combining a normal PDL-1 inhibitor like Keytruda with an IDO inhibitor was meant to broaden its spectrum of covered diseases, and consequently its potential sales volume, however the negative results have resulted in a drop for the whole sector. Indeed, not only have Incyte’s and Merck & Co’s shares declined, but also shares in Nektar Therapeutics (-7%) and New Link Genetics, which has an IDO inhibitors portfolio (-43%). As a result, part of the multi-billion investment in approximately 1,000 clinical trials assessing Keytruda or other immunotherapies on thousands of patients is now at risk, many analysts say.