IGM Biosciences Advances Novel IGM-6268 Antibody Through Clinical Trials for the Treatment and Prevention of COVID-19

In vitro studies indicate that IGM-6268 exhibits potent neutralizing activity against the Omicron variant and all other variants of concern and variants of interest tested –

– Phase 1 IGM-6268 clinical trials progress in the United States and South Africa –

MOUNTAIN VIEW, Calif., Feb. 9 10, 2022 (GLOBE NEWSWIRE) — IGM Biosciences, Inc. (Nasdaq: IGMS), a clinical-stage biotechnology company focused on the creation and development of engineered IgM antibodies, today announced its progress in two phase 1 trials. clinical trials evaluating IGM-6268, an anti-SARS-CoV-2 IgM monoclonal antibody, for the treatment and prevention of COVID-19. The first, a Phase 1 clinical trial in the United States, is a multicenter, randomized, double-blind, single-dose (SAD) and multiple-dose (MAD) placebo-controlled study to assess safety, tolerability and pharmacokinetics of IGM-6268 administered intranasally in healthy volunteers. The first two dose cohorts of healthy volunteers have been successfully approved in the United States and study data are expected in the first half of 2022. The second, a Phase 1a/1b clinical trial in South Africa, is a multicenter, randomized, double-blind, placebo-controlled study to assess the safety, tolerability, pharmacokinetics, and preliminary efficacy of IGM-6268 administered first intranasally in healthy volunteers, once an appropriate dose cohort has been eliminated, in outpatients with mild to moderate COVID 19. The first healthy volunteer dose cohort has been cleared into the study in South Africa, and the study data is expected in mid-2022.

IGM also announced today that the results of in vitro pseudovirus testing by a widely recognized commercial laboratory indicates that IGM-6268 exhibits neutralization of the Omicron variant (B.1.1.529) at an IC50 of 230 ng/mL, as well as potent in vitro neutralization activity against all other variants of concern (VoC) and variants of interest (VoI) of SARS-CoV-2 tested to date, including the Delta variant. This indicated IC50 for the Omicron variant is expected to be well below concentrations achievable by intranasal administration at major sites of infection and viral replication, based on previous observations from animal studies. These results are based on data previously published in Naturewherein IGM-6268 exhibited significantly increased potency against wild-type SARS-CoV-2 compared to an IgG antibody with the same binding domains and exhibited potent neutralization against Alpha (B.1.1.7), Gamma (P.1), and beta (B.1.351), as well as other receptor binding domain mutants that conferred resistance to several IgG antibodies cleared for emergency use.

“IgM antibodies are the first antibodies produced by the immune system when a virus attacks, and they demonstrate very high avidity, or overall binding strength, against the viral antigens they target,” said Chris Takimoto, MD, PhD, Medical Director of IGM. Biosciences. “Our in vitro neutralization data suggest that engineered IgM antibodies, due to their inherently enhanced avidity and altered specificity, provide resilience against the emergence of resistant variants of SARS-CoV-2, while demonstrating superior potency compared to an IgG antibody with the same binding domains.

About the IGM-6268
IGM-6268 is a modified IgM antibody that specifically targets the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. This humanized pentameric IgM antibody has 10 spike protein binding sites. IGM-6268 is being developed as a treatment or prophylaxis for symptoms associated with mild to moderate COVID-19 with intranasal administration plus intraoral spray once for 1 day (SAD), or once or twice per day for 5 days (MAD). The main mechanism of action of IGM-6268 is to block the binding of SARS-CoV-2 RBD on the spike protein to human angiotensin-converting enzyme 2 (hACE2), the cellular receptor for SARS -CoV-2. By blocking this binding, IGM-6268 neutralizes the infectivity of the virus. In preclinical studies, IGM-6268 has been shown to be highly effective in preventing and treating COVID-19 after intranasal administration. Due to its ability to bind SARS-CoV-2 with greater strength, IGM-6268 offers advantages over an IgG antibody with the same binding domains, including 50 to 500-fold neutralizing potency superior against wild-type virus and a greater ability to effectively neutralize some Concern variants and variants of interest, such as Delta and Omicron variants, compared to an IgG antibody with the same binding domains.

About IGM Biosciences, Inc.
Based in Mountain View, Calif., IGM Biosciences is a clinical-stage biotechnology company focused on the creation and development of engineered IgM antibodies. Since 2010, IGM Biosciences has worked to overcome barriers to protein manufacturing and engineering that have limited the therapeutic use of IgM antibodies. Through his efforts, IGM Biosciences has created a proprietary IgM technology platform for the development of IgM antibodies for clinical indications where their inherent properties may offer advantages over IgG antibodies.

Caution Regarding Forward-Looking Statements
This press release contains forward-looking statements, including statements relating to IGM’s plans, expectations and forecasts and future events. These forward-looking statements include, but are not limited to: the potential and expectations regarding IGM’s technology platform, its IgM antibodies and IGM-6268; statements regarding IGM’s Phase 1 clinical trials of IGM-6268, including the expected timing of data from such trials; IGM’s plans and expectations regarding its development strategy and operations for IGM-6268; and statements from IGM’s Chief Medical Officer. These statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results to differ materially, including, but not limited to: potential delays and disruptions resulting from the COVID-19 pandemic. 19 and government responses to the pandemic, including any future impacts on IGM’s operations, the manufacturing of its product candidates, the progress of its clinical trials, enrollment in its current and future clinical trials, and the progress of its collaborations and related efforts; the early stages of IGM’s clinical drug development; the risks associated with the use of modified IgM antibodies, which is a new and unproven therapeutic approach; IGM’s ability to demonstrate the safety and efficacy of its product candidates; IGM’s ability to successfully and timely advance its product candidates through preclinical studies and clinical trials; IGM’s ability to enroll patients in its clinical trials; the possibility that clinical trial results will differ from preclinical, preliminary, initial or expected results; the risk of significant adverse events, toxicities or other adverse side effects; IGM’s ability to successfully manufacture and deliver its product candidates for clinical trials; the potential impact of continuing or worsening supply chain constraints; the risk that all necessary regulatory approvals may not be obtained; the potential market for IGM’s product candidates, the potential diminished need for treatments to combat COVID-19, particularly in the United States and other major markets, and the progress and success of currently available alternative treatments or in development; IGM’s ability to obtain additional capital to fund its operations, if necessary; uncertainties associated with projections of the size of the patient populations suffering from the diseases targeted by the IGM; IGM’s ability to obtain, maintain and protect its intellectual property rights; developments regarding IGM’s competitors and its industry, including competing product candidates and therapies; the risks associated with collaborations with third parties, including the risk of the occurrence of any event, change or other circumstance that may give rise to the termination of such collaboration; general economic and market conditions; and other risks and uncertainties, including those more fully described in IGM’s filings with the Securities and Exchange Commission (SEC), including IGM’s Annual Report on Form 10-K filed with the SEC on March 30, 2021, IGM’s Quarterly Report on Form 10-Q filed with the SEC on November 4, 2021 and in IGM’s future reports to be filed with the SEC. All forward-looking statements contained in this press release speak only as of the date hereof, and IGM specifically disclaims any obligation to update any forward-looking statement, except as required by law.

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Irene B. Bowles