On June 14, 2024, the FIH dosing safely completed in the Phase I clinical trial of YKST02 (anti-CD3×BCMA), a bispecific antibody drug independently developed by Excyte Biopharma Ltd. (Excyte), for the treatment of relapsed/refractory multiple myeloma (RRMM), at the Affiliated Beijing Chaoyang Hospital of Capital Medical University, achieving another important milestone after the project was launched. The subject did not report any immediate adverse reactions post infusion. To ensure the safety of the subject during the following days and collect clinical data related to the treatment, the research team is closely monitoring the subject's situation and will share information with all parties involved in the project in a timely manner.

This Phase I study aims to evaluate the safety and tolerability of YKST02 in patients with RRMM. It is led by the principal investigator Dr. Wenming Chen of the Affiliated Beijing Chaoyang Hospital of Capital Medical University. The phase I trial is planned to be conducted in multiple sites across the country.

Besides the research team, staff in Beijing Highthink Pharmaceutical Technology Service Co. Ltd. and teams of the Affiliated Beijing Chaoyang Hospital of Capital Medical University had worked closely to screen appropriate subject for FIH dosing, showcasing the 'Excyte speed' in moving the candidate drug to clinical trial. Excyte is committed to advancing YKST02's clinical progress and pushing forward the product into market as soon as possible, so that it may benefit more RRMM patients and improve their quality of life. The company and her partners are excited about advancing YKST02's clinical trials and exploring new indications.

YKST02, developed by Excyte, is a bispecific antibody with a 2+2 symmetric structure based on the company’s unique fusion of IgG and scFv technology (FIST) platform. It is positioned to be a best-in-class drug for multiple myeloma patients, utilizing the same mechanism of action as BCMA-targeting CAR-T therapy. Preclinical data shows that YKST02 is safer and more effective than Teclistamab from J&J. The Investigational new drug (IND) application was submitted to the Center for drug evaluation (CDE) of National Medical Product Administration (NMPA) China on February 26, 2024, and approved within two months, demonstrating the sufficiency of the preclinical study data for clinical trials.

As Dr. Andy Yuan, CEO of Excyte stated, "Our company is dedicated to the development of novel antibody products that possess global commercial value and superior therapeutic profile”. Currently, the primary challenges in the development of CD3 bispecific antibodies for activating T cells engagers (TCEs) to kill tumor cells lie in the clinical safety issue caused by severe cytokine storm (CRS) and neurotoxicity. To address the concerns, our company has developed the FIST platform, by which derived products effectively mitigate the risk of CRS through multiple approaches while also significantly enhancing the drug's other properties, thus positioning them as next generation TCEs. The superiority of the FIST platform has been clearly demonstrated in the Phase I clinical trial of our first candidate drug, YK012, targeting CD19 and CD3. Based on the FIST platform, the company is developing other urgently needed drugs. "For better to be different, making good medicines affordable for general public" is the company's purpose in developing each product, and we hope that through our efforts, we can benefit more patients.

Excyte was co-founded by Andy Yuan and Qingwu Meng, who are oversea Chinese from  renowned international pharmaceutical companies in US. The company leverages the information and technology of China and the United States to develop innovative bispecific antibodies for cancers, and non-cancer indications. With the progress of the in-house pipeline, the company will have more novel candidate drugs entering clinical stage, potentially offering better options for urgently-needed patients.