Covid-19 crisis: Gilead working on combo of remdesivir, other drugs

Even as India awaits the commercial launch of remdesivir, US drug major Gilead Sciences is studying other molecules like rheumatoid arthritis drugs — baricitinib and tocilizumab — as combination therapies with remdesivir. 

Patient recruitment for the tocilizumab combination therapy study will begin this month.

Meanwhile, the company said it applied for a new drug application (NDA) in India for remdesivir in order to support the voluntary licensees based in India. 

For this, Gilead recently signed non-exclusive voluntary licensing agreements to further expand supply of the drug. It could not comment on a timeline for launching the drug in the Indian market. 

A Gilead spokesperson said, “The timeline to get remdesivir to Indian patients that need it will depend on the licensees. Our individual licensees will also file applications with the Central Drugs Standard Control Organisation (CDSCO) to manufacture and sell remdesivir, while waiving the requirement for undertaking local clinical trials.”

Licensees here — Cipla, Hetero Labs, Jubilant Lifesciences and Mylan — are yet to get a marketing authorisation for remdesivir. 

Company sources indicate that they are ready with the product and are awaiting clarity from the Drug Controller General of India (DCGI) on animal toxicology study requirements. The company cannot start commercial production without the product licence from the drug controller. 

Meanwhile, some states in India like Maharashtra that are severely affected by the virus have indicated that they are open to sourcing the drug from other countries like Bangladesh if need be at a cost of Rs 12 crore for 10,000 vials, or around Rs 12,000 per vial. Under World Trade Organisation provisions, lesser developed countries like Bangladesh can produce generic versions of patented drugs without seeking a licence. 

Even as patients here await the drug to be made available in the market, its innovator has started working on other potential combinations with the drug and expects results soon. Experts feel that this is imperative as the new coronavirus mutates fast and one has to keep looking for new drugs to combat it. 

A scientist working on repurposed drugs in the department of science and technology, Government of India, said that this virus is mutating quite fast. 

“The drugs we are trying to use on patients to improve recovery are basically using a pathway to stop or reduce the virus from replicating inside a human cell. As the virus mutates, a drug’s pathway may not work and thus it may lose efficacy. We would have to keep looking for new drugs,” he said. 

After remdesivir, an antiviral drug originally developed for Ebola, came into limelight for being effective in recovery of Covid-19 cases, the US company started working on other drugs that could be used as a combination with the primary drug remdesivir to help critically ill Covid patients. The spokesperson said, “We recognise that combination therapies may be required to further improve outcomes for patients with Covid-19 who are critically ill. We are actively exploring additional studies of remdesivir in combination with other drugs and will share information as it becomes available.”

The spokesperson also added that at this stage, however, the highest priority is the clinical development of remdesivir together with ongoing in vitro screening of other antivirals against the virus that causes Covid-19. “While we are studying remdesivir and monitoring emerging data on other drugs being explored to treat patients with Covid-19. National Institute of Allergy and Infectious Diseases (NIAID) will be evaluating a combination of remdesivir and baricitinib in an upcoming study. We will share further details on planned studies in the near future,” the person said. 

Gilead has teamed up with another multinational Roche and already announced clinical collaboration to evaluate Roche’s tocilizumab (sold as Actemra) as a potential combination treatment for Covid-19.

“The Remdacta study is a randomised, double-blind, placebo-controlled Phase 3 clinical trial evaluating the safety and efficacy of remdesivir plus intravenous tocilizumab in hospitalised patients with severe Covid-19 pneumonia. The trial is being conducted globally.”

As we learn more about Covid-19, we know that some patients develop acute respiratory distress syndrome (ARDS), a severe inflammatory disease of the lungs, causing direct injury that leads to shortness of breath and rapid breathing. 

“This study aims to determine whether patients with severe Covid-19 may achieve additional benefit by combining remdesivir with tocilizumab to inhibit these inflammatory responses,” Gilead said.