GAVRETO Final Data Shows Years of Survival in Targeted Lung Cancer, Highlighting Critical Need for Testing

SOUTH SAN FRANCISCO, Calif. – March 31, 2026 – New long-term data published in the Journal of Clinical Oncology offers a profound message of hope for patients with a rare and aggressive form of non-small cell lung cancer (NSCLC). The final results from the Phase 1/2 ARROW clinical trial demonstrate that GAVRETO® (pralsetinib), a targeted therapy from Rigel Pharmaceuticals, provides robust and durable responses, extending patient survival by years.

The publication, which includes an additional 42 months of follow-up, solidifies the drug's role in treating metastatic rearranged during transfection (RET) fusion-positive NSCLC, a genetic alteration found in just 1-2% of NSCLC patients. For this specific group, the findings represent a significant leap forward from the outcomes expected just a few years ago.

"The final data from the ARROW study shows robust and durable responses with a manageable safety profile in patients with RET fusion-positive NSCLC, emphasizing the importance of early biomarker testing and suggesting that pralsetinib may be a valuable tool in the treatment armamentarium," said Dr. Justin F. Gainor, a lead investigator on the trial and Director of the Center for Thoracic Cancers at Mass General Brigham Cancer Institute. He also noted the drug's effectiveness in patients whose cancer had spread to the brain, a common and difficult-to-treat complication of the disease.

A New Standard of Survival

The clinical results from the ARROW study paint a clear picture of pralsetinib's impact. Among 259 patients with measurable disease, the overall response rate (ORR) was an impressive 70%, meaning their tumors significantly shrank or disappeared. This figure climbed to 78% for patients who had not received any prior treatment, underscoring its potential as a powerful first-line option.

Perhaps most striking is the data on survival. The median overall survival for all patients with measurable disease reached 44.3 months—nearly four years. For U.S. patients in the trial, the median survival was even longer, at 62.4 months, or more than five years. This stands in stark contrast to the historical prognosis for metastatic lung cancer before the advent of selective RET inhibitors, where median survival was often less than a year.

"These longer-term data further support pralsetinib's role as a first-line treatment option for RET fusion-positive NSCLC patients," said Dr. Lisa Rojkjaer, Rigel's chief medical officer, in a statement. The drug also demonstrated significant activity against central nervous system (CNS) metastases, with an intracranial response rate of 53% in patients with measurable brain tumors at baseline, offering a critical benefit for a challenging patient population.

The therapy, a once-daily oral pill, was generally well-tolerated, with a safety profile consistent with previous reports and no new safety signals observed over the extended follow-up period.

The Competitive Landscape and Rigel's Strategic Play

The success of GAVRETO places it at the forefront of a highly competitive niche in oncology, primarily alongside Retevmo (selpercatinib) from pharmaceutical giant Eli Lilly. Both drugs are highly selective RET inhibitors recommended as preferred first-line options in major clinical guidelines, including those from the National Comprehensive Cancer Network (NCCN).

Both therapies boast similar high response rates and good CNS penetration. However, a key distinction lies in the level of clinical evidence. Selpercatinib is supported by a randomized Phase III trial, the gold standard in clinical research, which directly compared it to chemotherapy. Pralsetinib's approval and data are based on single-arm studies like ARROW. While the durability and survival shown in the final ARROW data are compelling, the lack of a head-to-head comparison could influence physician choice and reimbursement decisions in some healthcare systems.

For Rigel Pharmaceuticals, a smaller biotech firm, the positive long-term data is a crucial strategic asset. The company acquired the U.S. rights to GAVRETO from Blueprint Medicines in early 2024 after Roche, its previous partner, exited the agreement. Rigel has since been working to establish its commercial footing in the competitive oncology space. Sales figures show a promising upward trend, growing from $1.9 million in the second quarter of 2024 to $9.0 million in the first quarter of 2025. This robust, peer-reviewed data provides Rigel's commercial team with powerful evidence to bolster physician confidence and drive market penetration against a much larger competitor.

The Diagnostic Hurdle: Finding the Right Patient

The remarkable efficacy of pralsetinib underscores a broader challenge in the era of precision medicine: a groundbreaking drug is only effective if it reaches the right patient. The benefits of GAVRETO are exclusive to the 1-2% of NSCLC patients whose tumors are driven by a RET fusion. This makes early, accurate, and comprehensive biomarker testing not just important, but essential.

Despite strong recommendations from oncology societies to use next-generation sequencing (NGS) to test for a wide panel of genetic mutations, adoption remains inconsistent. Research shows that while testing for more common mutations like EGFR is high, a significant number of patients are not tested for rarer drivers like RET fusions. One study in community oncology settings found that while 83% of patients had at least one biomarker tested, only 37% were tested for all nine recommended markers.

Numerous barriers contribute to this diagnostic gap. Oncologists face operational challenges, including insufficient tissue from biopsies, long turnaround times for test results, and complex reimbursement landscapes. Inadequate funding and inconsistent insurance coverage for broad genomic panels can force physicians to perform sequential single-gene tests, a slower and less efficient process that can exhaust precious tissue samples before a RET fusion is ever identified.

To bridge this gap, patient advocacy groups and medical organizations are pushing for systemic changes, including the standardization of reflex testing protocols, improved reimbursement policies for NGS, and continued education for healthcare professionals. The powerful survival data from the ARROW trial serves as a potent reminder that the full promise of targeted therapies like pralsetinib can only be realized when the diagnostic infrastructure is strong enough to find every patient who stands to benefit.