PharmAbcine Announces Collaboration Agreement with MSD to Evaluate Anti-VISTA Antibody PMC-309 in Combination with KEYTRUDA® (pembrolizumab)

DAEJEON,South Korea,Dec. 12,2022 -- PharmAbcine Inc. (KOSDAQ: 208340ks),a clinical-stage biotech company focusing on the development of next-generation antibody therapeutics,announced today that the Company has entered into a clinical collaboration agreement with MSD (Merck & Co.,Inc.,Rahway,NJ.,USA),to initiate a Phase I combination trial of PMC-309,a novel anti-VISTA (V-domain Ig suppressor of T cell activation) antibody,in combination with KEYTRUDA® (pembrolizumab),MSD's anti-PD-1 therapy.

Under the terms of the agreement,PharmAbcine will sponsor a Phase I study in Australia to evaluate the safety and clinical efficacy of the combination therapy for the treatment of multiple advanced solid tumors,and MSD will supply KEYTRUDA.

"We are excited to announce another pipeline combination project in collaboration with MSD besides olinvacimab,our lead anti-VEGFR2 antibody,undergoing a Phase II study in combination with KEYTRUDA in mTNBC (metastatic Triple Negative Breast Cancer) patients,"said Dr.Jin-San Yoo,CEO of PharmAbcine. "In preclinical studies,PMC-309 demonstrated significantly enhanced tumor growth reduction when used with an anti-PD-1 drug in in vivo mouse model compared to both monotherapies of PMC-309 and an anti-PD-1 drug.We look forward to the opportunity to investigate this approach in a clinical setting."

Dr. Yoo also added,"In comparison to the existing immuno-oncology drugs that directly activate T cells,PMC-309's distinct mechanism of indirectly activating T cells by inhibiting immunosuppressive cells may represent a novel strategy for patients who do not respond well or have become resistant to the existing treatments and are in need of new therapies. "We are optimistic about PMC-309's best-in-class potential,and we are particularly excited to continue to evaluate it in combination with KEYTRUDA,one of the key leading molecules in cancer immunotherapy."

Further details of agreement and clinical protocols were not disclosed.

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

About PMC-309

PMC-309 is a novel IgG1 anti-VISTA (V-domain Ig Suppressor of T cell Activation) antagonizing antibody that can be used for the treatment of various tumor types. By inhibiting VISTA,an immune checkpoint receptor mainly expressed on MDSC (Myeloid-Derived Suppressor Cells) and Tregs (regulatory T cells),it can play a pivotal role in maintaining the immunosuppressive environment around the tumor cells.

In the nonclinical studies,it has been discovered that PMC-309 can promote both innate immunity (monocyte activation,M1 macrophage proliferation) and adaptive immunity (T cell activation) unlike the existing drugs which show significant changes only in adaptive immunity. In addition,the in vivo data showed that PMC-309 demonstrated significantly improved tumor growth inhibition when used in combination with an anti-PD-1 drug compared to both monotherapies of PMC-309 and an anti-PD-1 drug. These findings suggest that PMC-309 can offer a new treatment strategy in immuno-oncology area as it can be used in combination with other drugs to improve their low-response rates.

The GLP-Toxicology studies were already completed,and no serious safety issues were observed. The Company plans to submit Clinical Trial Application in early 2023.

About PharmAbcine Inc.

PharmAbcine is a clinical stage public company developing next generation IgG based therapeutics to treat cancer,neovascular eye diseases,and vascular related unmet needs.

The Company's main pipeline assets include olinvacimab,the lead asset in clinical stage,and IND-ready preclinical assets with first-in-class potential such as PMC-309 and PMC-403.

Olinvacimab,the Company's lead asset,is undergoing a Phase II trial in combination with MSD's pembrolizumab for mTNBC patients in Australia. The Company entered the Phase II study to reconfirm the encouraging result from Phase Ib olinvacimab-pembrolizumab trial,delivering 50% ORR,67% DCR,and clean safety profile.

PMC-309,a novel anti-VISTA-antagonizing IgG in pan pH,is an immune checkpoint regulator that targets MDSC (myeloid derived suppressor cells) and M2 macrophages which play pivotal role in maintaining immunosuppressive TME (Tumor Microenvironment). The Company plans to submit Clinical Trial Application for a Phase I study in late 2022.

PMC-403 is a novel TIE2-activating antibody that stabilizes dysfunctional leaky disorganized pathological vessels and can be used for vascular-related eye disease,such as wet AMD (Age-related Macular Degeneration). The Company expects to submit an IND for a Phase I ophthalmology clinical trial in the second half of 2022.

One of other early-stage assets,PMC-005,is an anti-EGFRviii IgG that only binds to EGFRviii expressed on cancer cells and can be applied to various modalities including CAR-T,CAR-NK,CAR-Macrophage,T cell/NK cell engager,and Radio-Immunotherapy

For additional information about PharmAbcine,visit http://www.pharmabcine.comor follow on Youtubeand Linkedin.

For licensing deals,joint venture,co-development,and collaboration in research or antibody discovery inquiries,please contact:

Business Development Team

E-mail: bd@pharmabcine.com

Office line: +82 70 4279 5100

For investor relations and public relations inquiries,please contact:

IR/PR Team

Sungjun Park,Associate

E-mail: sungjun.park@pharmabcine.com

Office line: +82 70 4270 2637

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