Merck & Co. has gained approval for Keytruda for use in third line treatment of small cell lung cancer (SCLC).
Unusually for the runaway leader in the PD-1/PD-L1 immunotherapy field, Keytruda is playing catch up with its rivals in this tumour type, where BMS’ Opdivo is already approved as a third line therapy in SCLC, with Roche’s Tecentriq gaining a prized first line indication in March.
Analysts forecast this lead could help Roche generate $1.5bn in sales from the indication – but one that Merck has its eyes on.
Keytruda can now be used as a monotherapy for small-cell lung cancer patients (SCLC) who have progressed after platinum-based chemotherapy or other prior lines of treatment.
The drug’s approval was fast-tracked by the FDA following the results of its KEYNOTE-158 and KEYNOTE-028 trials. These trials showed that when Keytruda was given as monotherapy to SCLC patients whose cancer had progressed despite prior therapies, they had an objective response rate (ORR) of 19%.
Bearing in mind the normal caveats about comparing such studies, Keytruda’s KEYNOTE-158 and -028 trials suggest a small but significant advantage over Opdivo in overall response rate.
Merck is already exploring Keytruda’s use in combination with chemotherapy in a phase 3 KEYNOTE-604 study. This study focuses on recently-diagnosed patients with advanced-stage SCLC, which would put it in more direct competition with Tecentriq.
EvaluatePharma forecasts that Keytruda will be the top selling drug worldwide in 2024, with predicted sales of 17bn, its lead in non-small cell lung cancer (NSCLC) being the primary driver of this expected success.
Keytruda has also recently been filed as a first-line treatment for head and neck cancer, for use as a monotherapy and in combination with chemotherapy.