Adagio Therapeutics, a biotech developing antibody therapies that could potentially address the variants the continue to drive the spread of the novel coronavirus, has raised $336 million to conduct a pivotal study of its lead experimental treatment.
The new capital, a Series C round of funding, was led by RA Capital Management. It comes nine months after Waltham, Massachusetts-based Adagio launched with science from Adimab, a company that discovers and engineers antibodies. It’s led by co-founder and CEO Tillman Gerngross, the serial biotech entrepreneur who co-founded and remains CEO of Lebanon, New Hampshire-based Adimab. The parent company spun out the startup to develop drugs that could treat and prevent infection from SARS-CoV-2 and its variants, and also address coronaviruses that may infect humans in the future.
Variants are similar to the original virus, but with mutations that could make them more infectious or resistant to treatment. Adagio is developing antibody therapies that bind to regions of the spike protein that are highly conserved across coronaviruses, which is another way of saying that these parts do not change or change very little. By targeting conserved regions, Adagio aims to offer broad protection even as the novel coronavirus mutates.
Adagio’s Covid-19 antibody research traces its origins to the 2003 outbreak of severe acute respiratory syndrome (SARS), which was also caused by a coronavirus. According to research published in the journal Science, Adagio antibody ADG2 was produced by isolating antibodies from a SARS survivor. Those antibodies were screened for ones that can bind to SARS-CoV-2. According to the published results, in both lab and mouse tests, ADG2 produced similar or higher potency against the novel coronavirus compared against other antibody therapies.
ADG2 led to the development of a version that has a longer half-life that increases the durability of the treatment, potentially offering protection for up to one year. That antibody, called ADG20, began Phase 1 testing in health volunteers in February. The double-blind study is randomly assigning participants to receive ADG20, either as an intramuscular dose or via intravenous infusion, or a placebo. On Monday, Adagio said a pivotal Phase 1/2/3 clinical trial is also underway evaluating the drug in patients with mild-to-moderate Covid-19 who face a high risk that their disease could progress. According to a National Institutes of Health database, this pivotal study is expected to enroll 1,728 volunteers. Preliminary data could become available by the end of this year.
Adagio’s antibodies performed well in University of Oxford lab studies that evaluated several experimental antibody drugs against the P.1 variant that was first found in Brazil, the B.1.1.7 variant first identified in the United Kingdom, and B.1.351, which was first found in South Africa. According to peer-reviewed results published in March in the journal Cell, the three Adagio antibodies tested, including ADG20, “neutralized all variants, with all reaching a plateau at 100% neutralization.”
Also performing well in the Oxford research were S309, an antibody from Vir Biotechnology, and REGN10987 (later named imdevimab), one of two Regeneron Pharmaceuticals antibodies that were tested. Like Adagio’s antibodies, the Vir and Regeneron therapies showed little to no reduction in neutralization activity across the three variants, the paper said. Also noteworthy was the performance of AstraZeneca’s therapies. One of the company’s antibodies showed a modest reduction in neutralization against the Brazilian variant while two others from the company showed equal neutralization against all of the SARS-CoV-2 variants tested.
Eli Lilly’s two antibodies performed poorly in the Oxford tests; LY-CoV555 (later named bamlanivimab) showed almost a complete loss of neutralization against the Brazilian and South African variants. The Oxford tests also showed that the Brazilian variant escaped neutralization from Regeneron’s antibody REGN10933 (casirivimab), the second of two antibodies that comprise the cocktail that has FDA emergency use authorization for treating Covid-19.
Bamlanivimab was granted emergency authorization last November for use by itself as a treatment for Covid-19. But the drug had fallen out of favor due to ineffectiveness against variants. Last week, Lilly requested revocation of the authorization, which the FDA granted, citing resistance that variants have to that treatment alone. But the Lilly antibody cocktail that combines bamlanivimab with etesivimab remains available for use under emergency use guidelines, as does Regeneron’s antibody cocktail.
Adagio isn’t the only company that is making progress with its antibody research. Last week, Regeneron and partner Roche released positive data from a Phase 3 study showing that its antibody reduced the spread of Covid infection among people in the same household. Also notable was that the study evaluated an injectable formulation, which will be easier for both physicians and patients compared to the intravenously infused version currently granted authorization for emergency use.
Vir’s S309, like the antibody that is the basis for Adagio’s research, was also isolated from a SARS patient from 2003. That antibody is the basis of VIR-7831, which is engineered to bind to a part of the spike protein that is consistent across its variants.
The Vir drug works by blocking a virus’s entry into cells and by clearing away infected cells. Last month, an interim analysis showed “profound efficacy,” leading independent observers of the study to recommend stopping the clinical trial. Based on those results, Vir and partner GlaxoSmithKline have submitted a request for emergency authorization of VIR-7831 for the treatment of early Covid-19. While that antibody is an IV infusion, Vir and GSK are also in mid-stage testing of formulation that is an intramuscular injection.
Adagio’s latest financing continues the quick pace that the company has kept since its launch last summer with $50 million in Series A financing. Last November, the company closed an $80 million Series B round of funding led by GV. Adagio’s Series C financing gives it the capability to meet the scale of its clinical trial plans, according to Peter Kolchinsky, managing partner of RA Capital.
“We’ll not only need these antibodies to treat patients and keep them out of hospitals, but to passively vaccinate the millions of patients who don’t mount a strong enough response to available vaccines, allowing them to contribute to our herd immunity,” he said in a prepared statement. “That’s going to take large-scale manufacturing, and it makes sense to put those resources towards the best antibodies.
Kolchinsky added that the Adagio technology could have applications beyond SARS-CoV-2, such as treating future disease outbreaks, even seasonal flu.
The new Adagio financing included investment from Redmile Group, Federated Hermes, Foresite Capital, ArrowMark Partners, PremjiInvest, and another “leading healthcare investor” that was undisclosed. Earlier investors Fidelity Management & Research Company, OrbiMed, Polaris Partners, Mithril, GV, Population Health Partners, Adimab and Omega Funds also participated in Series C round. Some of the new investors are so-called crossover investors, firms that invest in both private and public companies. Participation of these investors is viewed as a sign that a company is preparing to go public.
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