BJ Bioscience Announces Clinical Collaboration with MSD to Evaluate BJ-001 in Combination with KEYTRUDA® (pembrolizumab)

SHANGHAI,March 28,2023 -- BJ Bioscience,Inc. BJ Bioscience,a biotech company focusing on discovery and development of novel biologics for cancer immunotherapy,today announced that it entered into a clinical trial collaboration and supply agreement with MSD (Merck & Co.,Inc.,Rahway,NJ,USA). The collaboration will allow for the evaluation of safety and efficacy ofBJ-001,a tumor-targeting IL-15 fusion protein,in combination with MSD's anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in an ongoing Phase 1 clinicaltrial.

BJ Biosciencewill evaluateBJ-001 plus KEYTRUDA as part of the company's ongoing trial in patients with locally advanced/metastatic solid tumors. In this trial,BJ-001 is studied as monotherapy or in combination with KEYTRUDA,for safety,tolerability,pharmacokinetics,pharmacodynamics,immunogenicity,and antitumor activity.

In monotherapy dose escalation cohorts,BJ-001 has demonstrated tolerable safety profiles,favorable PK/PDprofiles,and encouraging preliminary efficacyresults.

"BJ Bioscience is excited to collaborate with MSD,one of the world's leading multinational pharmaceutical companies," saidJoe Zhang,MD,PhD,cofounder and CEO ofBJ Bioscience. "Many consider KEYTRUDA to be one of the gold-standard medicines in the cancer immunotherapy arena. We believe BJ-001 may be a promising addition to this area. Our preclinical studies demonstrated that the combination ofBJ-001 and an anti-PD-1 antibody was well-tolerated and showed promising early antitumor activity compared to either drug alone as monotherapy. With itstumor-targeting properties,we're looking forward to evaluating BJ-001 in combination with KEYTRUDA as a potential new treatment option to benefit more cancer patients. This investigational combination is a key component of our BJ-001 development program."

KEYTRUDA® is a registered trademark ofMerck Sharp & Dohme LLC,a subsidiary of Merck & Co.,USA.

AboutBJ-001

BJ-001 is a tumor-targeting IL-15 fusion protein,designed to expand and activate cancer-fighting natural killer (NK) cells and CD8+ T cells,and to have selected distribution in tumors with high integrin-expression. Preclinical data have demonstrated the ability ofBJ-001 to accumulate in integrin-expressing tumors. Clinical data to date have shown Best-in-Class properties of BJ-001,including tolerable safety,dose-dependent and encouraging magnitude of stimulation and expansion of NK cells and CD8+ T cells with no impact on immunosuppressive regulatory T cells.

AboutBJ Bioscience,Inc.

BJ BioscienceInc. is a clinical stage biotech company creating next generation of immunotherapies for cancer,inflammation and autoimmunity using its trade secret protected antibody discovery and screening technology and SIB® bispecific antibody platform. BJ Bioscience's lead asset,BJ-001,is in Phase 1 clinical studies in the US and China. For more information,please visit theBJ Bioscience website: www.bjbioscience.com.

Contacts:

Media

bjbio@bjbioscience.com

Investors

joe.zhang@bjbioscience.com