The investigational therapy pralsetinib appeared effective and safe for patients with RET fusion-positive non-small cell lung cancer, according to topline data released by the agent’s manufacturer.
Pralsetinib (Blueprint Medicines) is a selective once-daily oral inhibitor of RET fusions and mutations.
RET activating fusions are implicated in about 2% of NSCLC cases, as well as 10% to 20% of papillary thyroid cancer cases. Approximately 90% of patients with advanced medullary thyroid cancer have RET mutations.
The ongoing phase 1/phase 2 ARROW trial evaluated pralsetinib for 400 patients with RET fusion-positive NSCLC. Most study participants (n = 354) received the proposed indicated dose of 400 mg daily.
Among 80 patients with RET fusion-positive NSCLC previously treated with platinum-based chemotherapy, 61% (95% CI, 50-72) achieved objective response per independent central review.
Among 26 patients with treatment-naive RET fusion-positive NSCLC, researchers reported an ORR of 73% (95% CI, 52-88) per independent central review. All patients had tumor shrinkage, and 12% achieved complete response.
Overall, 95% of patients had tumor shrinkage, including 14% of patients who had complete regression of target tumors.
Median duration of response had not been reached (95% CI, 11.3 months-not estimable).
Pralsetinib exhibited a safety profile similar to what had been observed in prior studies. The agent appeared well-tolerated, and most adverse events were grade 1 or grade 2.
Four percent of patients who received the 400 mg daily dose discontinued therapy due to treatment-related adverse events.
Complete data from the ARROW trial will be submitted for presentation at a future medical meeting. Healio will provide updates on the data when they are released.
“As the clinical data for pralsetinib have matured, with deep and durable responses along with robust evidence of activity against brain metastases, our confidence has continued to grow in the potential of pralsetinib to provide lasting benefit to a broad population of patients with RET fusion-positive NSCLC, including those with newly diagnosed unresectable or metastatic disease,” Andy Boral, MD, PhD, chief medical officer of Blueprint Medicines, said in a company-issued press release. "Now, with strong, centrally reviewed topline data, we feel a profound sense of urgency and have taken the first step toward making pralsetinib broadly available to patients by initiating a rolling new drug application submission to the FDA.”
Blueprint Medicines intends to complete a new drug application submission for pralsetinib for the RET fusion-positive NSCLC indication in the first quarter of this year.
The company expects to file a new drug application in the second quarter of the year to seek approval of pralsetinib for treatment of patients with medullary thyroid cancer who previously received an approved multikinase inhibitor.