Dialectic Therapeutics Announces Dosing of First Patient in Platinum-Resistant Ovarian Cancer (PROC)

DALLAS, Nov. 19, 2025 /PRNewswire/ -- Dialectic Therapeutics, Inc., a clinical-stage biotechnology company developing innovative anti-cancer drugs, today announced that patient dosing is underway in a clinical trial led by the renowned Drs. Elizabeth Stover, Joyce Liu, and Ursula Matulonis from the Dana-Farber Cancer Institute. Dr. Matulonis previously served as the Principal Investigator for the study that led to a recent FDA approval in platinum-resistant ovarian cancer (PROC).

Dr. Stover, the principal investigator and IND-holder of the study, has recruited the first two patients, with more now being considered for eligibility in this extraordinarily exciting trial. For more information about the trial, including eligibility criteria, call 877-338-7425 or visit: https://www.dana-farber.org/clinical-trials/25-076.

"The advance of DT2216 to this Phase 1b/2 trial represents a critical milestone, driven by compelling data from our Phase 1a and preclinical studies. We have a remarkable opportunity to impact patients' lives and are grateful for the leadership of our world-class collaborators at Harvard and Dana-Farber," said John D. Harkey Jr., Executive Chairman of Dialectic Therapeutics, Inc.

"New therapeutic options are very much needed for our patients with platinum-resistant ovarian cancer. The preclinical data is extremely compelling in terms of the likelihood of translating to the clinical setting, and we are very excited to test weekly paclitaxel and DT2216 for ovarian cancer," stated Dr. Ursula Matulonis, Chief of the Division of Gynecologic Oncology at the Dana-Farber Cancer Institute and professor of Medicine at Harvard Medical School.

Dr. Stover's trial builds on the Phase 1a clinical data and the preclinical results, generated by Dialectic and Harvard School of Public Health, which demonstrate complete tumor eradication in both in vivo and in vitro ovarian cancer models.

"The preclinical efficacy observed with DT2216 and paclitaxel is among the strongest results we have seen in preclinical models of high-grade serous ovarian cancer. It's exciting to be able to bring a new potential treatment option to the clinic for our patients," said Dr. Elizabeth Stover, Assistant Professor of Medicine at Harvard Medical School and a medical oncologist in the Division of Gynecologic Oncology.

DT2216 is a novel therapeutic designed to potently and selectively degrade BCL-XL, a key protein used by cancer cells to evade death.

The company's completed Phase 1a trial enrolled and treated 20 patients across six dose-escalating cohorts. This study established a recommended Phase 2 dose (RP2D) demonstrating a favorable safety and tolerability profile. Biomarkers from patients receiving the RP2D showed that DT2216 degraded the intended BCL-XL target protein in all patients within this dosing cohort, demonstrating powerful and precise target engagement.

In collaboration with Dr. Kristopher Sarosiek at Harvard School of Public Health, the effects of DT2216 were evaluated in cancer cell line and patient-derived xenograft (PDX) models of high-grade serous ovarian carcinoma (HGSOC), including OVCAR3 and the highly chemo-resistant DF83 PDX model. The combination of paclitaxel and DT2216 induced rapid tumor regressions and eradicated the tumors completely. Notably, tumors showed no evidence of regrowth after DT2216 treatment was discontinued.

"As a lab that investigates how tumor cells commit to cell death, we're encouraged by how cleanly the biology matches the pharmacology. DT2216 selectively engages the target – BCL-X_L – and potently initiates tumor cell death in combination with paclitaxel. It's exactly the trajectory we hope to replicate in patients," stated Dr. Sarosiek, Director of the Cell Death Laboratory at Harvard School of Public Health. "We've long sought to develop innovative therapies that directly target the proteins responsible for making tumor cells resistant to treatment, and DT2216 offers us the opportunity to finally achieve this in patients."

For more information about the company, please visit www.dtsciences.com

About Dialectic Therapeutics, Inc.
Dialectic Therapeutics, Inc. is a Texas-based, clinical-stage biotechnology company focused on creating innovative new technologies to treat cancer. True to the Socratic origins of its name, Dialectic embodies the pursuit of truth through rigorous scientific inquiry, challenging long-held assumptions regarding BCL-XL inhibition to identify breakthrough treatments. Dialectic has received multiple grants from the Cancer Prevention and Research Institute of Texas (CPRIT), including a Seed and Company Product Research grant to support the continued clinical development of DT2216 [DP210005].

Contact:
Joshua Sills, Chief Operating Officer
Email: [email protected]

SOURCE Dialectic Therapeutics, Inc.