Rondo Therapeutics Doses First Patient in Phase 1 Trial of RNDO-564, a First-in-Class Co-Stimulatory Bispecific Antibody Targeting Nectin-4 in Advanced Solid Tumors

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HAYWARD, Calif.--(BUSINESS WIRE)--Dec 3, 2025--

Rondo Therapeutics, a clinical-stage biopharmaceutical company pioneering next-generation T-cell engaging bispecific antibodies for solid tumors, today announced that the first patient has been dosed in its Phase 1/1b clinical trial evaluating RNDO-564, a first-in-class bispecific antibody targeting CD28 and Nectin-4, in adults with relapsed or refractory locally advanced or metastatic urothelial carcinoma (mUC) and other solid tumors associated with Nectin-4 expression.

“We engineered RNDO-564 to deliver the widest therapeutic window through localized CD28 co-stimulation at the tumor site for safe and effective anti-tumor activity,” said Shelley Force Aldred, Ph.D., Co-Founder and Chief Executive Officer of Rondo Therapeutics. “The initiation of this trial marks an exciting milestone for Rondo as we advance our first co-stimulatory bispecific antibody into the clinic.”

A New Therapeutic Approach for Nectin-4–Positive Cancers

RNDO-564 represents a first-in-class therapeutic modality designed to overcome the limitations of Nectin-4–targeting antibody-drug conjugates (ADCs): durability of response remains a clinical challenge, and treatment-related toxicities can lead to dose reductions or discontinuation. Many patients who initially respond to ADC/IO regimens relapse due to resistance or are unable to continue treatment because of adverse events including peripheral neuropathy and skin toxicities.

By engaging Nectin-4 on tumor cells and CD28 on T cells, RNDO-564 is designed to provide localized immune co-stimulation that drives robust and sustained anti-tumor activity while minimizing peripheral toxicity.

“With the growing use of ADC/IO combinations, there remains a significant unmet need for patients whose disease relapses or who cannot tolerate these regimens,” said Benjamin Garmezy, M.D., Associate Director of Genitourinary Research at Sarah Cannon Research Institute (SCRI), Medical Oncologist at SCRI Oncology Partners in Nashville, Tenn., where the first patient was dosed, and principal investigator for the RNDO-564-001 clinical trial. “There is promise in developing new treatment options that can extend disease control and improve quality of life for these patients.”

“We believe RNDO-564 has the potential to fill this gap by offering a differentiated, chemo-free therapeutic option that is both durable and well tolerated,” said Thomas Manley, M.D., Chief Medical Officer at Rondo Therapeutics.

Trial Design

The open-label, multicenter, first-in-human study will evaluate the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of RNDO-564 both as a monotherapy and in combination with pembrolizumab in adults with relapsed or refractory locally advanced or mUC. For more information, visit clinicaltrials.gov (NCT07218003).

Preclinical data demonstrate that RNDO-564:

• Elicited robust Nectin-4 and T-cell receptor-dependent mediated killing of Nectin-4-expressing tumor cells
• Inhibited tumors in vivo as monotherapy and in combination with checkpoint therapy
• Restored tumor cell killing function of serially stimulated T cells in vitro
• Maintained cytotoxicity in ADC-resistant cells

About Rondo Therapeutics

Rondo Therapeutics is a biopharmaceutical company breaking new ground in cancer therapy. The company’s mission is to advance bispecific antibody therapies that address unmet needs in the treatment of solid tumors. Rondo is developing a new class of bispecific antibodies designed to harness the immune system to target and eliminate tumors with enhanced safety. Rondo Therapeutics is supported by Canaan Partners, Red Tree Venture Capital, Johnson & Johnson, SV Health Investors, and Novo Holdings. In addition to RNDO-564, the company’s pipeline includes immune-engaging bispecifics for a range of solid tumors, including ovarian, endometrial, and renal cancers. For more information, please visit www.rondotx.com.

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CONTACT: Rondo Therapeutics

Meghana Rao, VP of Business Development

[email protected]

KEYWORD: CALIFORNIA UNITED STATES NORTH AMERICA

INDUSTRY KEYWORD: SCIENCE BIOTECHNOLOGY RESEARCH PHARMACEUTICAL ONCOLOGY GENERAL HEALTH HEALTH CLINICAL TRIALS

SOURCE: Rondo Therapeutics

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PUB: 12/03/2025 08:30 AM/DISC: 12/03/2025 08:31 AM

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