Loxo Oncology Inc. (NASDAQ:LOXO) gained $28.68 (21%) to $168.18 in morning trading Thursday after reporting response data from a Phase I trial of its ret proto-oncogene (RET) inhibitor LOXO-292 to treat RET-altered cancers. The data were released late Wednesday in an abstract ahead of the American Society of Clinical Oncology meeting in Chicago.
In 32 evaluable patients with RET fusion-positive tumors, oral LOXO-292 led to an overall response rate (ORR) of 69%, including an ORR of 65% in 26 non-small cell lung cancer (NSCLC) patients and 83% in six papillary thyroid cancer patients. Additionally, 84% of patients had radiographic tumor reductions of 19-67%.
LOXO-292 also led to tumor reductions of 9-45%, including two partial responses, in 11 of 14 evaluable patients with RET-mutant medullary thyroid cancer (MTC).
Blueprint Medicines Corp. (NASDAQ:BPMC), which is developing RET inhibitor BLU-667, was off $8.36 (10%) to $78.02 in morning trading Thursday.
At April's American Association for Cancer Research meeting, Blueprint reported data from the Phase I ARROW trial showing that BLU-667 led to an ORR of 50% in 14 evaluable patients with with RET-altered NSCLC. Among 25 patients with RET-altered MTC, BLU-667 led to an ORR of 40% (see BioCentury Extra, April 16).
With Thursday's moves, Loxo added more than $850 million in market cap, while Blueprint shed more than $350 million.