AC-699

CRANBURY, N.J.--( BUSINESS WIRE )--Accutar Biotechnology, Inc., a biotechnology company focusing on artificial intelligence (AI)-enabled drug discovery, announced today that the US Food and Drug Administration (FDA) has granted the investigation of AC699 a Fast Track designation for the treatment of patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor-2 (HER2)-negative, estrogen receptor 1 (ESR1)-mutated advanced or metastatic breast cancer with disease progression on or after at least 1 line of endocrine-based therapy. AC699 is an investigational orally bioavailable, chimeric degrader of estrogen receptor (ER) α currently in a Phase 1 trial. ER-positive/HER2-negative subtype is the most common subtype of breast cancer (~70%), and mutations in the estrogen receptor 1 (ESR1) gene are common (20-40%) among ER-positive/HER2-negative patients who received endocrine therapy in the metastatic setting. AC699 has demonstrated objective response rate (ORR) of 50% in patients with an ESR1 mutation, in an ongoing Phase 1 trial, presented at ASCO 2024. "Receiving Fast Track designation for AC699 from the FDA highlights their recognition of the serious and life-threatening nature of this malignancy, the critical unmet medical needs not fully addressed by existing therapies, and the potential of AC699 to fill in the gap," said Jie Fan, Ph.D., Chief Executive Officer of Accutar Biotechnology, Inc. "We look forward to working closely with the FDA to optimize and expedite the development program." The FDA’s Fast Track process is designed to facilitate the development and expedite the review of novel drugs intended to treat serious conditions and address significant unmet medical needs. Companies that receive Fast Track designation are eligible for more frequent meetings and communications with the FDA during clinical development and potentially accelerated approval and priority review, if relevant criteria are met. For more information on Fast Track Designation, please visit the FDA’s website at https://www.fda.gov/patients/fast-track-breakthrough-therapy-accelerated-approval-priority-review/fast-track . About AC699 and the Phase 1 Study (AC699-001) AC699 is an investigational orally bioavailable, chimeric degrader of estrogen receptor (ER) α. In preclinical studies, AC699 has demonstrated potent and selective protein degradation of ERα wildtype and mutants with favorable pharmacological properties, as well as promising anti-tumor activities in ER-positive animal tumor models. The purpose of the Phase 1 multi-center, open-label study is to assess the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of AC699 treatment in patients with ER-positive / HER2-negative locally advanced or metastatic breast cancer (NCT05654532). Additional information on this clinical trial can be found on www.clinicaltrials.gov . About Accutar Biotechnology, Inc. Accutar is a clinical stage biotech company focused on AI-enabled drug discovery, and its application to the discovery and development of clinically differentiated medicines. Be transformative. For patients. To learn more about Accutar, please visit us at www.accutarbio.com .

Differentiated Mechanism of Action of a Chimeric Degrader as Compared to Fulvestrant and Novel SERDs Treatment with AC699 Monotherapy Resulted in 21% ORR for All Evaluable Patients, and 50% for Those Who Had an ESR1 Mutation Favorable Safety and Tolerability Pro All Doses with No DLTs or ≥ Grade 3 Adverse Events Related to AC699 CRANBURY, N.J.--(BUSINESS WIRE)-- Accutar Biotechnology, Inc., a biotechnology company focusing on artificial intelligence (AI)-enabled drug discovery, announced data from an ongoing Phase 1 study of AC699 monotherapy in patients with ER-positive / HER2-negative locally advanced or metastatic breast cancer. The data will be presented in a poster discussion session at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL on June 1, 2024. AC699 is a potent and selective orally bioavailable, chimeric degrader of estrogen receptor (ER) α, and offers a potential new breast cancer treatment option based on a differentiated mechanism of action as compared to fulvestrant and novel SERDs with deeper ERα degradation as demonstrated in preclinical studies. AC699 is currently being evaluated in an ongoing Phase 1 clinical study as a single agent for the treatment of ER-positive / HER2-negative locally advanced or metastatic breast cancer (NCT05654532). The primary objectives are to evaluate the safety and tolerability of AC699. Secondary and exploratory objectives include pharmacokinetics, preliminary efficacy and pharmacodynamic evaluation. The study uses a 3+3 dose-escalation design, with once-daily oral dosing of AC699 at 100, 200, 300, 400, and 600 mg. Phase 1 Study Results: As of April 8, 2024, 29 participants were enrolled and treated with AC699 at doses ranging from 100-400 mg. The participants had a median of 5 (range 2-10) prior lines of therapy, including 3 (range 1-8) prior lines in the metastatic setting The objective response rate was 21% (4/19) and increased to 50% (4/8) for those who had an ESR1 mutation There were no > Grade 3 drug-related adverse events (AEs), no dose limiting toxicities, no discontinuations and no dose reductions due to AEs AEs related to AC699 occurred in 38% of participants and included nausea (14%), hot flush (14%), and fatigue (10%) The maximum tolerated dose had not been reached yet Details of the poster presentation at ASCO 2024 are as follows: Date/Time: June 1, 2024, 9:00 AM – 12:00 PM CDT Abstract Number: 3074 Title: Preliminary results from a phase 1 study of AC699, an orally bioavailable chimeric estrogen receptor degrader, in patients with advanced or metastatic breast cancer. Session: Developmental Therapeutics—Molecularly Targeted Agents and Tumor Biology Abstracts and full session details can be accessed through the ASCO meeting planner: Link "We are extremely pleased with the groundbreaking safety and efficacy that AC699 has demonstrated thus far in Phase 1, with early evidence of its best-in-class potential, especially for patients with ESR1 mutations,” said Jie Fan, Ph.D., Chief Executive Officer of Accutar Biotechnology, Inc. "We look forward to completing the dose escalation portion of the study and starting the Phase 2 study soon. We believe that the oral dosing of AC699 and its differentiated mechanism of action, as compared to fulvestrant and novel SERDs, can potentially provide a new safe and effective treatment option for this patient population.” About AC699 and the Phase 1 Study (AC699-001) AC699 is an investigational orally bioavailable, chimeric degrader of estrogen receptor (ER) α. In preclinical studies, AC699 has demonstrated potent and selective protein degradation of ERα wildtype and mutants with favorable pharmacological properties, as well as promising anti-tumor activities in ER-positive animal tumor models. The purpose of the Phase 1 multi-center, open-label study is to assess the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of AC699 treatment in patients with ER-positive / HER2-negative locally advanced or metastatic breast cancer (NCT05654532). Additional information on this clinical trial can be found on . About Accutar Biotechnology, Inc. Accutar is a clinical stage biotech company focused on AI-enabled drug discovery, and its application to the discovery and development of clinically differentiated medicines. Be transformative. For patients. To learn more about Accutar, please visit us at . View source version on businesswire.com: Contacts Jiaqi Ren Media@accutarbio.com Source: Accutar Biotechnology, Inc. View this news release online at: