Hummingbird Bioscience Announces Two HMBD-002 Poster Presentations at the Society for Immunotherapy of Cancer 2022 Annual Meeting

VISTA blockade with HMBD-002 reprograms tumor associated macrophages and promotes cytotoxic T-cell response in preclinical studies

HMBD-002 in combination with anti-PD-1 treatment shows enhanced anti-tumor efficacy compared to monotherapy arms in preclinical studies

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

SAN FRANCISCO,HOUSTON and SINGAPORE,Nov. 7,2022 -- Hummingbird Bioscience,a data-driven precision biotherapeutics company discovering and developing transformative biologic medicines for hard-to-treat diseases,today announced two poster presentations for HMBD-002,a unique anti-VISTA antibody,at the 37th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) being held November 10-12,2022 in Boston. The company will present a Trials in Progress poster summarizing the Phase 1 clinical trial design for HMBD-002 (NCT05082610)and a poster examining the anti-tumor effects of VISTA blockade by HMBD-002 in preclinical studies.

The first poster describes the Phase 1,open-label,multi-center,first-in-human trial evaluating HMBD-002 as a monotherapy and in combination with the anti-PD-1 therapy KEYTRUDA®(pembrolizumab). The pembrolizumab combination arm of the study will be conducted in collaboration with Merck & Co.,Inc.,Rahway,NJ,USA.

The second poster shares preclinical data demonstrating that VISTA blockade with HMBD-002 reprograms tumor-associated macrophages to an inflammatory phenotype and promotes cytotoxic T-cell response. HMBD-002 in combination with anti-PD-1 treatment shows enhanced anti-tumor efficacy compared to monotherapy arms.

"As we gain a better understanding of the complex biology of VISTA,our confidence regarding the potential benefit of VISTA blockade to cancer patients who do not respond to current therapies continues to grow," said Jerome Boyd-Kirkup,Ph.D.,Hummingbird Bioscience's Chief Scientific Officer. "We are excited to share the compelling new preclinical data for HMBD-002,our potential first-in-class anti-VISTA antagonist antibody with a unique epitope and antibody format and look forward to discussing longer-term clinical development plans and combination strategies with the wider immuno-oncology community at SITC."

SITC Trials In Progress Poster Details:

Abstract Title: A phase 1 first-in-human study of HMBD-002,an IgG4 monoclonal antibody targeting VISTA,as a monotherapy and combined with pembrolizumab in patients with advanced solid malignancies

Abstract Number:623

Where:Hall C

When: Thursday,November 10,2022 (9am to 9pm ET)

SITC Preclinical Poster Details:

Abstract Title: Anti-VISTA antibody HMBD-002 reprograms tumor associated macrophages and promotes cytotoxic T cell response

Abstract Number:532

Where:Hall C

When:Friday,November 11,2022 (9am to 830pm ET)

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

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).

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.