Rgenta Therapeutics Announces Successful End-of-Phase 2 Meeting with FDA and Alignment on Phase 3 Trial Design for RGT-61159 in Patients with Adenoid Cystic Carcinoma (ACC)

On October 22, 2026 Rgenta Therapeutics, a clinical-stage biotechnology company pioneering the development of a new class of oral small molecules targeting RNA and RNA regulation for oncology and neurological disorders, reported the completion of a successful end-of-Phase 2 meeting with the Food and Drug Administration (FDA) regarding the advancement of RGT-61159, the company’s oral small molecule targeting the MYB oncogene, into pivotal Phase 3 development in patients with adenoid cystic carcinoma (ACC).

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"Gaining alignment with the FDA on advancing RGT-61159 directly into a Phase 3 trial is a significant milestone for Rgenta and the patients we intend to serve," said Simon Xi, Ph.D., co-founder and chief executive officer of Rgenta. "This milestone is particularly rewarding following positive preliminary data from our Phase 1a/b clinical trial of RGT-61159 and a testament to the strength of the safety and efficacy data generated thus far. We believe RGT-61159 represents a promising and innovative potential therapy for patients with ACC, which is a rare, aggressive, malignancy for which no effective targeted therapies are available for patients with recurrent and/or metastatic disease."

Simon added, "We’d like to thank the patients and physicians who have supported our development of RGT-61159 as well as our dedicated team, whose science has translated into an encouraging therapeutic candidate and applaud their continued focus on the promise and potential our therapy may bring to patients."

"The Phase 3 clinical trial of RGT-61159 is expected to be the first study of its kind in ACC, marking an important step toward developing new treatment options for these patients," said Alan L. Ho, M.D., Chief of the Head and Neck Oncology Service at Memorial Sloan Kettering Cancer Center. "Early clinical data have demonstrated anti-tumor activity and a tolerable safety profile with once-daily oral dosing. We look forward to evaluating RGT-61159 in this Phase 3 trial and advancing research into new treatments for this rare, difficult-to-treat cancer."

Rgenta previously announced preliminary results from its ongoing Phase 1a/b clinical trial of RGT-61159, which is a multi-center, open-label dose escalation and expansion study (NCT06462183) in patients with advanced relapsed or refractory ACC or colorectal cancer (CRC). Preliminary data from the initial patients in the trial showed clinically meaningful disease control of 84.6% in 39 evaluable patients, with 3 patients achieving partial response according to RECIST criteria. Responses continued to deepen with longer treatment duration. Patients with partial responses have remained on study for a mean of 8.2 months, while all ongoing patients across the trial have a mean on-study duration of 7.3 months. RGT-61159 was well tolerated with the most common adverse events being fatigue, anemia, diarrhea, and nausea.

Highlights of the Planned Phase 3 Trial
The planned Phase 3 trial is a double-blind, placebo-controlled trial in approximately 150 patients with biomarker selected, locally advanced, incurable, recurrent or metastatic ACC. Patients will be randomized 2:2:1 to receive once daily oral RGT-61159 84 mg, RGT-61159 60 mg, or placebo. All patients will receive best supportive care. The primary endpoint is progression free survival (PFS). Key secondary endpoints include overall survival (OS), safety, and tolerability. The trial is expected to include sites in North America and Europe.

About RGT-61159
RGT-61159 is an orally available small molecule designed to specifically modulate splicing of the transcription factor MYB resulting in the inhibition of oncogenic MYB protein production, which has the potential to inhibit proliferation or induce cell death of cancer cells that overexpress MYB protein. MYB acts as a master regulator of cell proliferation, self-renewal, and differentiation processes and its aberrant expression has been demonstrated in multiple forms of human cancer including adenoid cystic carcinoma (ACC), acute myeloid leukemias (AML), T-cell acute lymphoblastic leukemias (T-ALL), colorectal cancer (CRC), small cell lung cancer (SCLC) and breast cancer.

About Adenoid Cystic Carcinoma (ACC)
It is estimated that approximately 200,000 people are living with ACC throughout the world, including 11,000 in the U.S. While it is a rare cancer, ACC is the second most common cancer type arising in the salivary gland and is an aggressive malignancy with a tendency to infiltrate surrounding nerves and metastasize to distant sites. Overactivation of the MYB oncogene has been described as a hallmark of ACC and is noted in over 90% of ACC. Treatment for ACC is extremely challenging and may include surgery and/or radiation, which often fails to control local tumor recurrence and distant metastases. There are no effective targeted therapies available for patients with recurrent and/or metastatic disease. There is thus an unmet medical need for new therapeutic targets and treatment strategies for patients with this fatal cancer.

(Press release, Rgenta Therapeutics, OCT 22, 2026, View Source [SID1234673693])