Immunome’s Antibody Cocktail Effective Against SARS-CoV-2 Omicron Variant in In Vitro Live Virus Testing

- Antibody Cocktail Demonstrates Comparable Head-to-Head Potency to GSK/Vir’s Sotrovimab in Live Virus Neutralization Assay Against Omicron (B.1.1.529) -

- IMM20253 Antibody Exhibits a Novel Mechanism of Action -

Immunome, Inc. (Nasdaq: IMNM), a biopharmaceutical company that utilizes its human memory B cell platform to discover and develop first-in-class antibody therapeutics, today announced in vitro data demonstrating effectiveness of its antibody cocktail against live versions of the SARS-CoV-2 Omicron variant (B.1.1.529) when tested at two external laboratories (Boston University’s National Emerging Infectious Diseases Laboratories and Washington University¹).

“We are pleased to report that, as predicted, Immunome’s antibody cocktail retained activity against Omicron in live virus testing,” said Purnanand Sarma, PhD, President & CEO of Immunome. “In recent weeks, there has been a significant reduction in the number of antibody therapeutics under Emergency Use Authorization that are active against Omicron, demonstrating a clear, immediate need for continued advancement of novel therapeutic approaches. Immunome’s cocktail includes an ACE2 independent mechanism of anti-viral activity, which offers a differentiated way to fight SARS-CoV-2 variants that we believe is less susceptible to variant drift than other treatments.”

Immunome shared the following updates regarding the effectiveness of the antibody cocktail:

• IMM20253 exhibits a novel mechanism of action not reported with any other Emergency Use Authorization (EUA) antibodies by promoting a proteolytic cleavage of the portion of the spike protein needed for ACE2 binding, thus reducing the ability of the virus to infect host cells. In addition, IMM20253 induces potent non-neutralizing activity via phagocytosis. The IMM20253 epitope appears to be broadly conserved across other betacoronaviruses, including SARS-CoV-1. When tested in both laboratories, IMM20253 retained similar potency against Omicron compared to reference strains.
• A head-to-head test using live virus was performed at Boston University’s National Emerging Infectious Diseases Laboratories to evaluate relative neutralization potency. In this assay, Immunome’s IMM20253/IMM20184 combination neutralized the Omicron variant within 3.5-fold potency (IC50 of 27 nM) compared to S309 (IC50 of 8 nM), the preclinical version of sotrovimab (GSK/Vir). According to the FDA’s EUA Fact Sheet for sotrovimab, <5-fold change in IC50 is considered no change in susceptibility.²
• In the live virus testing conducted by Boston University and Washington University, each using a different assay, the potency of the IMM20253/IMM20184 combination was measured to be in the range of 27 nM – 100 nM. For reference, in published literature^3,4, the neutralization potency of S309, the preclinical version of sotrovimab (GSK/Vir), ranged from 2.5 nM – 52 nM. As observed, significant variability exists in the measurement of neutralization potency depending on assay and test conditions.
• As a combination, IMM20253 and IMM20184 showed consistent neutralization across all former variants of concern in pseudovirus testing as well as all variants tested to date in live virus (WA1/2020, BavPat, Alpha and Beta). The neutralization activity against Omicron was primarily driven by IMM20253, with IMM20184 making a minor contribution to the overall in vitro neutralizing activity of the cocktail. The combination is expected to maintain non-neutralization activities, including complement activation and phagocytosis, potentially contributing to viral clearance mechanisms in vivo. IMM20190, the third component of IMM-BCP-01, which is effective against other variants (including Delta) in preclinical testing, was excluded from live virus testing due to Immunome’s prior predictive analysis suggesting a lack of binding to Omicron.

Based on this positive data, Immunome plans to continue advancing the program into Phase 1b.

This investigational work was funded by the U.S. Department of Defense’s (DOD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) in collaboration with the Defense Health Agency (DHA). (Contract number: W911QY-20-9-0019).

¹Dr. Michael Diamond, the WashU principal investigator, receives compensation as member of Immunome’s COVID-19 Advisory Board.

²https://www.fda.gov/media/149534/download

³https://www.biorxiv.org/content/10.1101/2021.12.14.472630v1.full.pdf

⁴ https://www.nature.com/articles/s41591-021-01678-y

About IMM-BCP-01

IMM-BCP-01 is a three-antibody cocktail targeting non-overlapping regions of the Spike protein of SARS-CoV-2, including highly conserved, subdominant epitopes, which elicits both ACE2 and non-ACE2 dependent neutralization, and induces natural viral clearance mechanisms, such as antibody dependent cellular cytotoxicity, complement activation and phagocytosis. When tested in vivo, these mechanisms combine to significantly reduce viral load in lungs of the hamsters infected with multiple variants of SARS-CoV-2 (WA1/2020, Alpha, and Beta). IMM-BCP-01 neutralizes all variants of SARS-CoV-2 tested to date in vitro. Immunome has submitted an Investigational New Drug Application with the FDA and plans to initiate a placebo-controlled dose escalation study in patients infected with SARS-CoV-2, pending the FDA’s acceptance of Immunome’s IND submission.

About Immunome

Immunome is a biopharmaceutical company that utilizes its proprietary human memory B cell platform to discover and develop first-in-class antibody therapeutics that are designed to change the way diseases are treated. The company’s initial focus is developing therapeutics to treat cancer and infectious diseases, including COVID-19. Immunome’s proprietary discovery engine identifies novel therapeutic antibodies and their targets by leveraging the highly educated components of the immune system, memory B cells, from patients whose bodies have learned to fight off their disease. For more information, please visit www.immunome.com.

Forward-Looking Statements

This press release includes certain disclosures that contain “forward-looking statements” intended to qualify for the “safe harbor” from liability established by the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, express or implied statements regarding Immunome’s beliefs and expectations regarding the advancement of its COVID-19 therapeutic antibody program, execution of its regulatory, preclinical, clinical and strategic plans, therapeutic potential and benefits of IMM-BCP-01 and anticipated upcoming milestones for IMM-BCP-01, as well as the timing and progress of each of the foregoing matters. Forward-looking statements may be identified by the words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “plan,” “project,” “suggest,” “may,” “will,” “could,” “should,” “seek,” “potential” and similar expressions. Forward-looking statements are based on Immunome’s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict. Factors that could cause actual results to differ include, but are not limited to, the following: the impact of the COVID-19 pandemic on Immunome’s business, operations, strategy, goals and anticipated milestones; the fact that research and development data are subject to differing interpretations and assessments, including during the peer review/publication process in the scientific community and by regulatory authorities; whether the data will be published in a scientific journal and, if so, when and with what modifications; Immunome’s ability to execute on its strategy, including with respect to its R&D efforts, IND submissions and other regulatory filings, timing of these filings and the timing and nature of governmental authority feedback regarding the same, initiation and completion of any clinical studies, confirmatory testing and other anticipated milestones as and when anticipated; the effectiveness of Immunome’s product candidates, including the possibility that further preclinical data and any clinical trial data may be inconsistent with earlier-published data and/or data used for advancing the product candidates; the fact that further variants could emerge and our ability to address those variants; Immunome’s ability to fund operations; Immunome’s reliance on vendors; the competitive landscape; and the additional risks and uncertainties set forth more fully under the caption “Risk Factors” in Immunome’s Annual Report on Form 10-K filed with the United States Securities and Exchange Commission (SEC) on March 25, 2021, and elsewhere in Immunome’s 10-Q filings and other filings and reports with the SEC. All statements contained in this announcement are made as of this date, and Immunome undertakes no duty to publicly update or revise any forward looking statements, whether as a result of new information, future events or otherwise, except as may be required under applicable law. In this press release, we may discuss our current and potential future product candidates that have not yet undergone clinical trials or been approved for marketing by the U.S. Food and Drug Administration or other governmental authority, including expectations about their therapeutic potential and benefits thereof. No representation is made as to the safety or effectiveness of these current or potential future product candidates for the use for which such product candidates are being studied.

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