In two firsts, Eli Lilly has won its first approval for a pipeline drug coming out of the $8 billion acquisition of Loxo Oncology—and it's the first therapy specifically meant for cancer patients whose tumors have a specific set of genetic alterations.
Friday, the FDA approved Retevmo, or selpercatinib, to treat lung and thyroid cancers that have a mutation or fusion to the RET gene, months ahead of schedule. This marks the first go-ahead for a drug targeting RET-driven tumors.
Lilly is making Retevmo available from specialty pharmacies within a week with a list price of about $20,600 for a 30-day supply, a Lilly spokesperson told FiercePharma, labeling the cost as “generally in line with other oral targeted therapies.”
Retevmo’s label carries warnings and other precautions for liver toxicity, hypertension, heart problems and other side effects. But that didn’t stop Cantor Fitzgerald analyst Louise Chen from granting the drug a blockbuster sales target, which she said is above the Street’s current estimates.
The FDA nod is based on data from the single-arm phase 1/2 Libretto-001 trial in three different subsets of patients. Retevmo shrank tumors in 64% of 105 patients with RET fusion-positive non-small cell lung cancer that had already been treated with chemo, and 84% of 39 patients who hadn't received previous treatment.
Among patients with medullary thyroid cancer, the RET inhibitor induced a response in 69% of previously treated patients and 73% of those who hadn’t had therapy before. The overall response rates for RET fusion-positive thyroid cancer were 79% and 100% for previously treated and new patients, respectively.
The Indianapolis pharma is currently enrolling patients in two confirmatory trials, Libretto-431 and Libretto-531.
Lilly beat Blueprint Medicines to market, but its rival isn’t so far behind. Blueprint’s RET inhibitor pralsetinib, also known as BLU-667, hit a 61% response rate in RET fusion-positive NSCLC patients. The company recently completed a submission under the FDA’s real-time oncology review pilot program, which is designed to accelerate its cancer drug evaluations. It’s expected to present more detailed data on the drug at the upcoming American Society of Clinical Oncology virtual event.
During a Blueprint conference call last week, CEO Jeff Albers said the biotech plans to file for previously treated RET-mutant medullary thyroid cancer also under that FDA accelerated review pathway. What’s more, the FDA has invited it to participate in the Project Orbis initiative, which allows for a simultaneous review of oncology drugs by regulatory bodies in the U.S., Canada and Australia.
Lilly has a first-mover advantage and its NSCLC data looked better on certain fronts, Cantor’s Chen noted in a Sunday dispatch to clients. But during the call, Blueprint Chief Commercial Officer Christina Rossi said she doesn’t expect a significant lag between the two drugs' approvals. She also touted pralsetinib’s complete response rates as something physicians have found “incredibly compelling” and potentially “differentiating.”
For Lilly, Retevmo is the first pipeline drug green-lit from its Loxo buyout, which was carried out to rejuvenate its oncology portfolio. Loxo also developed TRK inhibitor Vitrakvi, a drug approved by the FDA to target tumors with a genetic alteration regardless of their locations. But that drug—along with a follow-on candidate, LOXO-195—was snatched up by Bayer, which exercised an option triggered by the Loxo takeover to beef up its own pipeline.
Besides Retevmo, Loxo’s BTK inhibitor LOXO-305 belongs to Lilly. At the 2019 American Society of Hematology annual meeting, it reported positive preliminary results from a phase 1/2 trial in heavily pretreated blood cancer patients.
Editor's Note: Carly Helfand also contributed to the reporting.