Myeloma Drug Shown to Treat Covid-19 Patients

Sea squirt (Dimitris Siskopoulos, Flickr)

19 Oct. 2020. Results from an early clinical trial show a drug designed to treat multiple myeloma also reduces viral loads and hospital stays of patients with Covid-19 infections. The proof-of-concept findings were released on Friday by the biopharmaceutical company PharmaMar SA, in Madrid, Spain.

PharmaMar develops drugs to treat blood-related and solid tumor cancers derived from compounds found in invertebrate marine organisms. One of the company’s drugs is plitidepsin, made from compounds in the sea squirt, a marine animal known formally as Aplidium albicans. Plitidepsin, marketed by PharmaMar as Aplidin, is authorized in Australia as a treatment for the blood-related cancer multiple myeloma, and designated as an orphan drug in the U.S. and Europe.

The company says its preclinical studies show plitidepsin also has anti-viral properties, eliminating colonies of coronaviruses, including SARS-CoV-2 responsible for Covid-19 infections. Because PharmaMar studied plitidepsin as a cancer therapy, its basic safety in patients was already known. But the company needed to confirm its safety in hospitalized Covid-19 patients, some with serious symptoms, as well as discover its efficacy as a Covid-19 treatment.

To answer those questions, PharmaMar conducted an early-stage clinical trial with 45 individuals at 13 sites in Spain hospitalized with Covid-19 infections. Participants were randomly assigned to receive infusions of 1.5, 2.0, or 2.5 milligrams of plitidepsin for three consecutive days. The study had no placebo or control group.

The study team then tracked the patients for 31 days looking primarily for signs of adverse reactions to plitidepsin, as well as a number of specific biomarker levels. The researchers also measured viral loads in patients, and tracked the overall conditions of participants, including the need for further hospitalization, supplemental oxygen, and mechanical ventilation.

PharmaMar says nearly all, 90 percent, of patients had medium or high SARS-CoV-2 loads at the beginning of the trial, but as soon as four days following treatment with plitidepsin, viral loads began to drop. By day seven following treatment, says the company, viral loads in participants were reduced by half on average, while by day 15 viral loads were reduced to 70 percent of their original levels.

The company says results show plitidepsin also reduces hospitalization time. Treatment protocols require seven days in the hospital, but by day eight, 38 percent of patients were released and by day 15 after infusion, 81 percent were allowed to go home. In addition, by day 30 none of the participants showed any signs or symptoms of Covid-19. Moreover, says PharmaMar, declines in patients’ viral loads correlated highly with resolution of pneumonia and reductions in inflammation indicators, such as C-reactive protein.

PharmaMar says in a company statement that after discussions with Spanish authorities, “in order to keep the study open in hospitals, and to allow patient access to plitidepsin, the company has obtained the authorization for an extension of the patient cohort. This extension will help to obtain more data on the treatment of this indication.” PharmMar also expects to begin discussions with regulatory agencies for a late-stage clinical trial of Covid-19 patients requiring hospitalization.

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