The Food and Drug Administration has agreed to give Eli Lilly's (LLY 0.31%) cancer drug selpercatinib a priority review, which will shave four months off the review time. The agency is expected to deliver a decision about the marketing application in the third quarter of 2020, although it could come sooner considering that the drug has been given a "breakthrough therapy" designation.
Eli Lilly inherited selpercatinib, which used to go by the code name LOXO-292, through its $8 billion acquisition of Loxo Oncology last year. Much of the value of that company was tied to its already-approved cancer therapy Vitrakvi, but selpercatinib was touted as the pipeline drug to watch.
Selpercatinib inhibits a protein called RET, which is involved in cell signaling in the presence of growth factors. The gene becomes altered in some tumors, leading to uncontrolled cell growth.
Eli Lilly has applied for approval of the treatment in three different types of tumors with altered RET: non-small-cell lung cancer, medullary thyroid cancer, and thyroid cancer. Its application is based on data from the Libretto-001 phase 1/2 clinical trial, where initial results showed response rates between 45% and 77% in the different types of tumors. More recent results focused on lung cancer patients showed 68% of them responding to the treatment.
In December, the pharmaceutical company started two phase 3 clinical trials: Libretto-431 in lung cancer patients and Libretto-531 medullary thyroid cancer patients. Both studies will enroll patients who hadn't been previously treated, so in addition to confirming the results from the phase 1/2 study, data from the new studies could be used to pursue an expanded approval that would increase the population of patients approved to be treated with selpercatinib.