WILMINGTON, Del. — September 10, 2026
Prelude Therapeutics Incorporated announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for PRT13722, an investigational oral KAT6A selective degrader being developed for patients with hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer. The FDA clearance enables Prelude to advance the program into human clinical development, with the company expecting to begin enrolling patients in the fourth quarter of 2026. The first-in-human Phase 1 study is designed to evaluate PRT13722 as both a monotherapy and in combination with endocrine and targeted therapies in adults with locally advanced or metastatic HR+/HER2- breast cancer. The regulatory milestone marks an important step for Prelude’s precision oncology strategy, particularly its effort to develop highly selective protein degraders against clinically validated cancer targets.
PRT13722 Targets Selective KAT6A Degradation
PRT13722 is designed to selectively degrade KAT6A while sparing KAT6B, an approach that Prelude believes could provide a wider therapeutic window than conventional dual KAT6A/B inhibition. KAT6 has emerged as a clinically validated target in ER-positive breast cancer, while recent clinical findings have provided further support for targeting the pathway in HR+/HER2- disease, including tumors carrying actionable mutations. Prelude’s strategy is based on the potential advantages of selective KAT6A degradation, including stronger target engagement, improved tolerability and greater flexibility for combination treatment. The company has developed PRT13722 as a highly potent, highly selective and orally bioavailable degrader, with preclinical findings supporting its potential to deliver antitumor activity while reducing hematological liabilities associated with dual KAT6A/B inhibitors. The selective mechanism could be particularly relevant as treatment strategies increasingly incorporate endocrine and targeted therapies across earlier and later lines of breast cancer care.
Phase 1 Study to Evaluate Safety and Antitumor Activity
The Phase 1 clinical trial will assess the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity of PRT13722. The open-label, multicenter, first-in-human study will enroll adults with locally advanced or metastatic HR-positive, HER2-negative breast cancer and will evaluate PRT13722 both as a single agent and in combination with endocrine and targeted therapies. The combination component is strategically important because patients with HR+/HER2- disease frequently receive treatment regimens built around endocrine therapy and molecularly targeted agents. Prelude believes the selective KAT6A approach could support broader combination opportunities if the compound demonstrates an appropriate safety and pharmacological profile. Initial patient enrollment is expected in the fourth quarter of 2026, establishing the next clinical milestone for PRT13722. Data from the study will help determine dose selection and characterize biological activity as Prelude works toward defining the compound’s potential role in precision treatment of breast cancer.
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Prelude Expands Precision Oncology Degrader Pipeline
The FDA clearance strengthens Prelude Therapeutics’ broader precision oncology pipeline centered on targeted protein degradation and highly selective molecular approaches. In addition to its KAT6A degrader programs, the company is developing JAK2V617F mutant-selective inhibitors and next-generation degrader antibody conjugates (DACs) featuring novel payloads. The advancement of PRT13722 provides Prelude with an opportunity to translate its protein-degradation expertise into clinical development against a validated oncology target while addressing limitations associated with existing KAT6-directed approaches. The company’s central strategy is focused on developing medicines for cancers with significant unmet needs by combining molecular selectivity with differentiated pharmacology. With FDA clearance secured and Phase 1 enrollment planned for late 2026, Prelude is positioning PRT13722 as a potential next-generation KAT6-directed therapy and an important clinical component of its precision oncology development strategy.
Source: Prelude Therapeutics, press release
