- Blueprint Medicines has started submitting one of its targeted cancer drugs for approval, a decision supported by new clinical trial results that showed three in five lung cancer patients with a certain genetic profile responded to the drug.
- The trial enrolled non-small cell lung cancer patients who tested positive for RET fusions, meaning a gene called RET has fused with another gene, in turn affecting the cell signaling protein which it normally encodes. Foundation Medicine, a diagnostics company, estimates 1% to 2% of lung cancers and up to 5% of thyroid cancers occur in patients with abnormalities in the RET gene.
- Blueprint expects to complete the lung cancer application for its drug, named pralsetinib, sometime in the first quarter. The biotech also intends to ask regulators to approve pralsetinib as a treatment for medullary thyroid cancer, with an application planned for the second quarter. Those submission would put Blueprint several months behind Eli Lilly, which filed its own RET-targeting cancer drug in the fourth quarter.
The fresh pralsetinib data show that, among 80 RET fusion-positive lung cancer patients who were previously treated with chemotherapy, tumors shrunk in 61% after they were given the drug. For another 26 patients who hadn't received cancer treatment before, the response rate was 73%.
The biotech also reported that median duration of response, a measure of how long after treatment a patient's cancer begins to grow or spread, had not yet been reached for the patients who previously received platinum-based chemotherapy. On safety, Blueprint said its drug was well-tolerated, and that 4% of patients stopped taking it because of treatment-related adverse events.
As Blueprint begins sending these results off to regulators, Wall Street analysts are at odds about their strength compared to what was reported for Lilly's rival drug.
Lilly picked up selpercatinib through its $8 billion acquisition of Loxo Oncology. Clinical results presented last year at a global lung cancer conference showed that, among 105 patients with RET fusion-positive non-small cell lung cancer, there was a 68% response rate after treatment with selpercatinib. And among 34 patients who hadn't before received cancer treatment, the response rate was 85%.
Those results should help Lilly's case that it holds a best-in-class RET inhibitor, according to Cantor Fitzgerald analyst Louise Chen, who has an "Overweight" rating on the company. Chen writes in a new investor note that, while difficult to compare across trials, the response seen in the selpercatinib data "continues to look better than" Blueprint's topline data.
Andrew Berens, an SVB Leerink analyst with an "Outperform" rating on Blueprint, homed in on a different data point. Though he acknowledged the difference in objective response rates between Blueprint's and Lilly's drugs, he also highlighted how the complete response rate among treatment-naive cancer patients was 12% for pralsetinib but 3% for selpercatinib.
That the pralsetinib study has yet to reach a median duration of response is another good sign for Blueprint, according to Berens, as it provides evidence the drug offers lasting benefits.
Lilly's drug, meanwhile, demonstrated a 20-month overall median duration of response in lung cancer patients.
Raymond James analyst Dane Leone has a "Strong Buy" rating on Blueprint and expects both the biotech's drug and Lilly's to secure approval in thyroid and non-small cell lung cancers.
Which one becomes the frontrunner, however, is still up for debate.
"Regarding which drug will be preferred within the clinical community, the definitive answer will likely be based upon," median duration of response and median progression free survival, or mPFS, Leone wrote in a note to investors.
"At this point, we know that selpercatinib has produced an impressive [mPFS of greater than 18 months] within a patient population that was previously treated with a median of 3 prior therapies," he added, "but we do not have a clear view of what the durability of response with pralsetinib would be across a similar patient population."
Blueprint and Lilly's stock prices were essentially unchanged Wednesday morning.
A Lilly spokesperson said the company does not yet have a approval decision deadline from the Food and Drug Administration for selpercatinib.