IGM Biosciences Advances Novel Antibody IGM-6268 Into Clinical Trials for the Treatment and Prevention of COVID-19
– In vitro studies indicate IGM-6268 exhibits potent neutralization activity against the Omicron variant and all other Variants of Concern and Variants of Interest tested –
– IGM-6268 Phase 1 clinical trials advancing in
IGM today also announced that results from in vitro pseudovirus testing conducted by a widely recognized, commercial laboratory indicate that IGM-6268 exhibits neutralization of the Omicron (B.1.1.529) variant at an IC50 of 230 ng/mL, as well as potent in vitro neutralization activity against all other SARS-CoV-2 Variants of Concern (VoC) and Variants of Interest (VoI) tested to date, including the Delta variant. This indicated IC50 for the Omicron variant is expected to be well below the concentrations achievable by intranasal administration in key sites of infection and viral replication, based on previous observations from animal studies. These results expand upon data previously published in Nature, in which IGM-6268 exhibited significantly increased potency against wild type SARS-CoV-2 relative to an IgG antibody with the same binding domains and exhibited potent neutralization against the Alpha (B.1.1.7), Gamma (P.1), and Beta (B.1.351) variants, as well as other receptor-binding domain mutants that conferred resistance to several IgG antibodies authorized 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
IGM-6268 is an engineered IgM antibody that specifically targets the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. This humanized pentameric IgM antibody has 10 binding sites to the spike protein. IGM-6268 is being developed as a treatment or prophylaxis for symptoms associated with mild to moderate COVID-19 with administration by intranasal plus intraoral spray once for 1 day (SAD), or once or twice each day for 5 days (MAD). The primary mechanism of action of IGM-6268 is to block the binding of the 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 to SARS-CoV-2 with greater strength, IGM-6268 offers advantages over an IgG antibody with the same binding domains, including 50-500x greater neutralizing potency against wildtype virus and greater ability to effectively neutralize certain Variants of Concern and Variants of Interest, such as the Delta and Omicron variants, as compared with an IgG antibody with the same binding domains.
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements, including statements relating to IGM’s plans, expectations, and forecasts and to future events. Such forward-looking statements include, but are not limited to: the potential of, 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 activities for IGM-6268; and statements by IGM’s Chief Medical Officer. Such 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 disruption resulting from the COVID-19 pandemic and governmental responses to the pandemic, including any future impacts to IGM’s operations, the manufacturing of its product candidates, the progression of its clinical trials, enrollment in its current and future clinical trials and progression of its collaborations and related efforts; IGM’s early stages of clinical drug development; risks related to the use of engineered IgM antibodies, which is a novel 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 potential for the results of clinical trials to differ from preclinical, preliminary, initial or expected results; the risk of significant adverse events, toxicities or other undesirable side effects; IGM’s ability to successfully manufacture and supply its product candidates for clinical trials; the potential impact of continuing or worsening supply chain constraints; the risk that all necessary regulatory approvals cannot be obtained; the potential market for IGM’s product candidates, the potential diminishing need for therapeutics to address COVID-19, particularly in
Source: IGM Biosciences, Inc.