Zhejiang Doer Biologics Announces Clinical Trial Collaboration with MSD to Evaluate DR30303 in Combination with KEYTRUDA® (pembrolizumab) in Patients with Gastric or Gastroesophageal Junction Cancer

HANGZHOU,China,Dec. 16,2022 -- Hangzhou,Zhejiang,[December 9th,2022],Zhejiang Doer Biologics Co.,Ltd. ("Doer Bio"),a clinical stage biopharmaceutical company developing innovative biotherapeutics for metabolic diseases and cancers,today announced that it has entered into a clinical trial collaboration agreement with MSD (Merck & Co.,Inc.,Rahway,NJ,USA),to investigate Doer Bio's anti-Claudin18.2 antibody DR30303,in combination with MSD's anti-PD-1 therapy,KEYTRUDA® (pembrolizumab),in patients with Gastric or Gastroesophageal Junction Cancer.

Under this agreement,Doer Bio will conduct a clinical study based on a mutually- agreed and finalized protocol,to evaluate the safety and efficacy of DR30303 in combination with KEYTRUDA® in patients with Claudin18.2-positive,locally advanced unresectable or metastatic gastric or gastroesophageal junction (GC/GEJ) cancer.

"DR30303 is a humanized anti-Claudin18.2 heavy chain antibody Fc fusion protein (VHH-Fc) generated via Doer Bio's proprietary SMART-VHHBody platform. We believe DR30303 exhibits strong and highly selective binding to Claudin18.2,enhanced antibody-dependent cellular cytotoxicity (ADCC) activity,and low immunogenicity risk. Its smaller size may allow DR30303 to penetrate solid tumors faster and deeper. We believe that DR30303 is a potential best-in-class anti-Claudin18.2 antibody." said Yanshan Huang,Ph.D.,founder and Chief Executive Officer of Doer Bio. "DR30303 has shown favorable safety profile in ongoing trials as monotherapy and displayed encouraging anti-tumor signals in patients with Claudin18.2-positive solid tumor. We are excited to test DR30303 in combination with KEYTRUDA® for the treatment of Claudin18.2-positive GC/GEJ cancer." commented Yongliang Fang,Chief Operating Officer of Doer Bio.

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

About DR30303

DR30303 is a humanized anti-Claudin18.2 heavy chain antibody Fc fusion protein (VHH-Fc) generated via Doer Biologics' proprietary SMART-VHHBody platform. Claudin 18.2 is an attractive target for cancer treatment due to its tumor specificity and aberrant overexpression in gastric cancer and pancreatic adenocarcinomas. DR30303 exhibits strong and highly selective binding to Claudin18.2,enhanced antibody-dependent cellular cytotoxicity (ADCC) activity as a result of Fc engineering,and low immunogenicity risk validated via in-silico T-cell epitope predictor. It demonstrated promising anti-tumor activity,both alone and in combination with chemotherapies and PD-1 checkpoint blockade,in a variety of murine tumor models,and favorable pharmacokinetic properties in preclinical studies.

About Doer Bio

Zhejiang Doer Biologics Co.,Ltd. ("Doer Bio") is a clinical stage biopharmaceutical company that focuses on the discovery and development of multi-domain based multi-specific biotherapeutics to address unmet medical need in the field of metabolic diseases and cancers.

Doer Bio has developed multiple proprietary platform technologies,including xLONGylation®,MultiBody®,AccuBody®,and SMART-VHHBody. For more information about Doer Bio,please visit www.doerbio.com.

View original content to download multimedia:https://www.prnewswire.com/news-releases/zhejiang-doer-biologics-announces-clinical-trial-collaboration-with-msd-to-evaluate-dr30303-in-combination-with-keytruda-pembrolizumab-in-patients-with-gastric-or-gastroesophageal-junction-cancer-301704808.html