NEW YORK –The US Food and Drug Administration on Wednesday granted accelerated approval to Eli Lilly's Retevmo (selpercatinib) for treatment of patients with locally advanced or metastatic solid tumors bearing RET gene fusions who have progressed on prior systemic therapy or have no remaining treatment options.
Retevmo is the first RET inhibitor to garner tumor-agnostic approval. However, the FDA has previously granted tumor-agnostic approval to two checkpoint inhibitors: Merck's Keytruda (pembrolizumab) for refractory cancer patients with a certain level of tumor mutational burden and those with mismatch repair deficiency or high microsatellite instability, and GlaxoSmithKline's Jemperli (dostarlimab) for patients with dMMR tumors. The agency has also granted tissue-agnostic approval to Bayer's Vitrakvi (larotrectinib) and Genentech's Rozlytrek (entrectinib) for refractory patients with NTRK-rearranged solid tumors.
According to the FDA, its accelerated approval of Retevmo in the tissue-agnostic setting comes two months ahead of the expected response date. The agency reviewed data from the Phase I/II LIBRETTO-001 trial involving 343 patients with RET-fusion-positive solid tumors.
Data from the non-small cell lung cancer and thyroid cancer cohorts in this trial supported FDA accelerated approval of the drug in these tumor types in 2020. On Wednesday, in addition to granting tissue-agnostic approval to Retevmo based on data from 41 patients with cancers other than NSCLC and thyroid cancer, the agency also converted those earlier histology-specific accelerated approvals to regular approval and expanded the label to include patients with locally advanced disease.
The data from LIBRETTO-001's other cohorts showed that patients with soft tissue sarcoma, cholangiocarcinoma, cancers of unknown primary, and colorectal, salivary, breast, small intestine, and pancreatic tumors also responded to Retevmo. The overall response rate in the trial was 44 percent among 41 evaluable patients with a duration of response of 24.5 months. Of 16 patients that had measurable central nervous system metastases at the start of the trial, researchers observed responses in 14 patients, or 87.5 percent. Thirty-nine percent of responders had an intracranial duration of response of 12 months or more.
"These data and the FDA approval of the tumor-agnostic indication underscore the importance of routine, comprehensive genomic testing for patients across a wide variety of tumor types," Vivek Subbiah, associate professor of investigational cancer therapeutics at the MD Anderson Cancer Center and a LIBRETTO-001 co-investigator, said in a statement.
Common adverse reactions such as edema, diarrhea, and fatigue affected less than 25 percent of trial participants. Retevmo's label includes warnings for a range of potentially serious adverse events including hepatotoxicity, interstitial lung disease, and QT interval prolongation.
In June, the European Medicines Agency granted marketing authorization to the drug, branded Retsevmo, as a first-line monotherapy for patients with NSCLC harboring RET gene fusions. That approval was also based on LIBRETTO-001.