Hummingbird Bioscience Announces HMBD-002 Trials in Progress Poster at ASCO Annual Meeting 2023

HMBD-002,a non-depleting,high-affinity anti-VISTA antibody,possesses key design features enabling robust anti-tumor activity in preclinical models,positioning it as a potentially important new therapy for VISTA-expressing cancers including triple-negative breast cancer and non-small cell lung cancer

HMBD-002 is currently being assessed in a Phase 1 study to determine the recommended Phase 2 dose as a monotherapy and in combination with pembrolizumab

Monotherapy escalation cohorts 1-4 have been completed without dose-limiting toxicities

SAN FRANCISCO and HOUSTON and SINGAPORE,May 29,2023 -- Hummingbird Bioscience,a data-driven precision biotherapeutics company discovering and developing transformative biologic medicines for hard-to-treat diseases,today announced a Trials in Progress poster presentation for HMBD-002,a unique anti-VISTA antibody,at the American Society of Clinical Oncology (ASCO) Annual Meeting being held 2-6 June,2023 in Chicago. The poster will summarize the Phase 1 clinical trial design for HMBD-002 (NCT05082610).

The poster describes the Phase 1,open-label,multi-center,first-in-human trial evaluating HMBD-002 as a monotherapy and in combination with Merck & Co.,Inc.,Rahway,NJ,USA's anti-PD-1 therapy KEYTRUDA® (pembrolizumab). The study will be conducted under a clinical trial collaboration and supply agreement with Merck & Co.,USA. Monotherapy escalation cohorts 1-4 have been completed without dose-limiting toxicities,and the trial is currently enrolling cohort 5. Combination escalation is projected to begin in the second half of 2023.

"VISTA's complex biology makes it a hard-to-drug target,yet we have shown in our preclinical studies that HMBD-002 has potent anti-tumor activity with its unique mechanism of action. In this poster at ASCO,we will display the progress that HMBD-002 has made in Phase 1 trials," said Jerome Boyd-Kirkup,Ph.D.,Hummingbird Bioscience's Chief Scientific Officer. "We look forward to discussing longer-term clinical development plans and combination strategies with the wider immuno-oncology community at ASCO."

ASCO Trials In Progress Poster Details:

Poster Title: A phase 1 first-in-human clinical trial of HMBD-002,an IgG4 monoclonal antibody targeting VISTA,in advanced solid tumors

Poster Session Track: Developmental Therapeutics—Immunotherapy

Poster Session Date: June 3,2023

Time: 8:00 AM – 11:00 AM CDT

Location: Hall A

Poster Board Number: 505b

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

About Hummingbird Bioscience

Hummingbird Bioscience is a data-driven precision biotherapeutics company discovering and developing transformative biologic medicines for hard-to-treat diseases. The Hummingbird Bioscience model combines computational and systems biology with wet lab drug discovery in a multi-disciplinary,collaborative environment spanning initial discovery through clinical development. We harness this integrated approach across target identification and patient selection,enabling our team to increase the efficiency of translating novel scientific insights while reducing the inherent risk in drug discovery and development. We are currently developing two clinical stage assets: HMBD-001,a humanized anti-HER3 monoclonal antibody targeting a novel epitope on HER3,and HMBD-002,a humanized anti-VISTA IgG4 monoclonal antibody. Both programs are currently in Phase 1 studies. At Hummingbird Bioscience,our commitment to rigorous science,teamwork,and intellectual integrity underpins our passion to accelerate the journey of new drugs from concept to clinic.

For more information,please visit www.hummingbirdbioscience.com,and follow Hummingbird Bioscience on LinkedIn,Twitter,and YouTube.

About HMBD-002

HMBD-002 is an investigational IgG4 anti-VISTA antagonist antibody produced by our Rational Antibody Discovery ("RAD") platform to target the region where VISTA interacts with binding partners that have been shown to play an important role in modulating T cell activity,potentially unlocking the immune system to attack cancer cells. Due to complex biology,VISTA has not been adequately drugged to date. We believe HMBD-002 is the first Fc-independent anti-VISTA antibody designed to bind a computationally predicted functional epitope distinct from the epitopes of other known anti-VISTA antibodies in development. In the Company's preclinical studies,HMBD-002 demonstrated potent anti-tumor activity both as monotherapy and in combination with pembrolizumab,in multiple syngeneic and humanized mouse models of cancers. HMBD-002 is being developed for various VISTA-expressing cancers,both as a monotherapy and in combination with pembrolizumab. The development of HMBD-002 is supported in part by a grant from the Cancer Prevention and Research Institute of Texas (CPRIT,DP190027).