The recombinant fusion protein CD24Fc – also known as SACCOVID - was shown to reduce the risk of death or respiratory failure in severe or critical COVID-19 cases by more than 50%, in a recently released Phase 3 interim analysis.
Data from 203 participants (75% of planned enrolment) also indicated that patients treated with a single dose of CD24Fc showed a 60% higher probability of improvement in clinical status (as defined by the protocol) compared to placebo.
Based in Rockville, Maryland, Oncolmmune works on discovering and developing biopharmaceuticals for the treatment of cancer and autoimmune disease.
While Merck will take control of CD24Fc, certain related rights and assets unrelated to CD24Fc will be spun-out to a new entity, owned by the existing shareholders of Oncolmmune with Merck taking a minority stake in the new entity and investing $50m.
COVID-19 candidate represents 'potential breakthrough in treating severe & critical COVID-19’
Merck (known as MSD outside the US and Canada), through a subsidiary, will acquire all outstanding shares of OncoImmune for an upfront payment of $425m in cash. OncoImmune shareholders will also be eligible to receive sales-based payments and payments on the achievement of certain regulatory milestones.
“Meaningful new therapeutic options are desperately needed for possibly millions of people around the world who will develop severe or critical COVID-19 disease,” said Dr. Roger M. Perlmutter, President, Merck Research Laboratories.
“Recent clinical investigations support the view that CD24Fc may provide benefit beyond standard of care therapy for COVID-19 patients requiring oxygen support, and hence will represent an important addition to the Merck pipeline of investigational medicines and vaccines designed to address the COVID-19 pandemic.”
Phase 3 trial in hopitalized patients
As OncoImmune’s lead product, CD24Fc is a recombinant fusion protein that targets the innate immune system.
Prior to the Phase 3 clinical trial for COVID-19 patients, CD24Fc has been studied for safety in healthy volunteers and in Phase 2 clinical trials for the prevention of graft versus host disease (GVHD) following hematopoietic stem cell transplantation in patients with leukemia. A pivotal Phase 3 clinical trial (NCT04095858) for prophylaxis of GVHD has been initiated nationwide.
The SAC-COVID Phase 3 clinical trial (NCT04317040) is a randomized, double blind, placebo-controlled trial designed to evaluate the safety and efficacy of CD24Fc in hospitalized patients with COVID-19 requiring oxygen support, including those requiring supplemental oxygen, high flow oxygen, and mechanical ventilation.
Releasing topline results from the interim efficacy analysis in September, OncoImmune said CD24Fc displayed ‘superb therapeutic efficacy’ and represented a ‘potential breakthrough in treating severe and critical COVID-19’.
As the trial did not exclude other experimental therapeutics, many participants also received Remdesivir and/or corticosteroids including dexamethasone. Among them, those who were treated with SACCOVID (CD24Fc) and Remdesivir recovered 7 days earlier than those who received Remdesivir and placebo (median time to recovery 6 days vs 13 days).
Those who were treated with SACCOVID and corticosteroids recovered 10 days earlier than those who received corticosteroids and placebo (median time to recovery 5 days vs 15 days).
Merck's COVID-19 pipeline: vaccines and anti-virals
Merck’s other COVID-19 efforts include a collaboration with Miami-headquartered Ridgeback Biotherapeutics to evaluate molnupiravir (EIDD-2801), an investigational orally available anti-viral candidate, in two Phase 2/3 trials, for the treatment of patients with COVID-19 in both outpatient and inpatient settings.
The company is also conducting clinical trials to evaluate two SARS-CoV-2/COVID-19 vaccine candidates: both of which are currently in Phase 1 trials. The one-dose candidate V590 is being developed through a collaboration with IAVI, using a recombinant vesicular stomatitis vector. Meanwhile, V591 (either one or two doses) uses a measles virus vector-based platform and is being developed with Institute Pasteur.