• CRB-601 shows dose-dependent antitumor activity correlating with increased binding to αvβ8 in pre-clinical tumor models
• CRB-601 enhances anti-PD-1 immunotherapy efficacy and induces long-lasting tumor-specific cytotoxic T-cells
• IND submission for CRB-601 on track for 2H 2023

NORWOOD, Mass., April 17, 2023 /PRNewswire/ -- Corbus Pharmaceuticals Holdings, Inc. (NASDAQ: CRBP) ("Corbus" or the "Company"), a precision oncology company, today announced details of new pre-clinical data on CRB-601, its avβ8 blocking antibody, presented as a poster at the 2023 American Association for Cancer Research (AACR) annual meeting, held April 14-19, 2023 in Orlando, FL.

The poster titled "CRB-601, an avβ8 blocking antibody, prevents activation of TGFβ and exhibits anti-tumor activity associated with immune cell remodeling of the tumor microenvironment" explores the relationship between CRB-601 antitumor activity, PK and its binding to the αvβ8 receptor in the tumor. In addition, the impact on TGFβ pathway signaling and tumor immune cell population are also presented. Tumor growth was evaluated in mice bearing orthotopically implanted murine breast cancer EMT6 or colon cancer MC38 and treated with CRB-601.

CRB-601 exhibited dose dependent tumor growth inhibition (TGI) in the EMT6 tumor model which was significantly augmented in combination with anti-PD1 therapy. These effects were associated with changes in tumor micro-environment (TME) immune cell populations with marked increases in infiltrating T cells, NK cells and M1 polarized macrophages. Efficacy correlated with cell surface αvβ8 occupancy by CRB-601. CRB-601 treatment downregulated phosphorylation of SMAD proteins pSMAD2 and pSMAD3, consistent with blockade of the canonical TGFβ signaling pathway.

Rachael Brake, PhD, Chief Scientific Officer of Corbus stated: "We are building on our early efficacy. We can now demonstrate that CRB-601 has robust anti-tumor activity alone and as a combination partner with anti-PD-1 and that these effects are associated with documented receptor engagement, a reduction of TGFb1 levels in the tumor micro-environment (TME), and inhibition of downstream canonical TGFb signaling. Together this data reinforces the potential of this new approach in blocking activation of TGFb locally in the TME."

About Corbus
Corbus is a precision oncology company committed to helping people defeat serious illness by bringing innovative scientific approaches to well understood biological pathways. Corbus' current pipeline includes CRB-701, a next generation antibody drug conjugate that targets the expression of Nectin-4 on cancer cells to release a cytotoxic payload and CRB-601, an anti-integrin monoclonal antibody that blocks the activation of TGFβ expressed on cancer cells. Corbus is headquartered in Norwood, Massachusetts. For more information on Corbus, visit corbuspharma.com. Connect with us on Twitter, LinkedIn and Facebook.

Forward-Looking Statements    
This press release contains certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and Private Securities Litigation Reform Act, as amended, including those relating to the Company's restructuring, trial results, product development, clinical and regulatory timelines, market opportunity, competitive position, possible or assumed future results of operations, business strategies, potential growth opportunities, the Company's compliance with Nasdaq's continued listing criteria and other statement that are predictive in nature. These forward-looking statements are based on current expectations, estimates, forecasts and projections about the industry and markets in which we operate and management's current beliefs and assumptions.

These statements may be identified by the use of forward-looking expressions, including, but not limited to, "expect," "anticipate," "intend," "plan," "believe," "estimate," "potential," "predict," "project," "should," "would" and similar expressions and the negatives of those terms. These statements relate to future events or our financial performance and involve known and unknown risks, uncertainties, and other factors, including whether the Company will be able to regain and maintain compliance with Nasdaq's continued listing criteria, the potential impact of the COVID-19 pandemic and the potential impact of sustained social distancing efforts, on our operations, clinical development plans and timelines, which may cause actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include those set forth in the Company's filings with the Securities and Exchange Commission. Prospective investors are cautioned not to place undue reliance on such forward-looking statements, which speak only as of the date of this press release. The Company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.

INVESTOR CONTACT:

Sean Moran
Chief Financial Officer
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Bruce Mackle 
Managing Director
LifeSci Advisors, LLC
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