Rigel Pharmaceuticals (Nasdaq: RIGL) announced it will present clinical data on its drug GAVRETO (pralsetinib) at the European Society for Medical Oncology (ESMO) Congress in Madrid, Spain, running October 23 to October 27, 2026.

A pooled analysis of 49 patients with RET fusion-positive solid tumors from the ARROW and TAPISTRY clinical trials, excluding non-small cell lung cancer (NSCLC) and thyroid tumors, showed an overall response rate (ORR) of 53% and a median duration of response of 12.2 months. Patients with previously treated pancreatic tumors had an ORR of 88% (7 of 8 patients).

In the TAPISTRY trial cohort of 16 response-evaluable patients with RET fusion-positive thyroid cancer, pralsetinib showed an ORR of 81.3%.

In the ARROW trial, patients with RET fusion-positive NSCLC treated with pralsetinib in the first-line setting had an investigator-assessed ORR of 75%, compared with 26% for patients who had received standard-of-care first-line therapies before enrollment. Median times to progression, treatment discontinuation, and next treatment or death were also longer with first-line pralsetinib.

A separate analysis from the ARROW trial found that at least 75% of evaluable patients with advanced or metastatic RET fusion-positive NSCLC experienced improved or stable health-related quality of life scores across all assessed domains at Cycle 12 Day 1.

The pooled ARROW and TAPISTRY data will be presented in a rapid oral session on October 25, 2026. Additional findings will be featured in two poster presentations and an ePoster on October 26, 2026, according to a company press release.

Alison L. Hannah, M.D., Rigel's chief medical officer, said the analyses "provide important new insights into its clinical activity, durability and impact on patients" across RET fusion-positive cancers.

GAVRETO is approved by the FDA for adult patients with metastatic RET fusion-positive NSCLC and for patients 12 and older with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy.