First monoclonal antibody for Covid-19 treatment: Tocilizumab

The WHO (World Health Organization) prequalified the drug Tocilizumab for treating moderate to severe patients of Covid-19. The WHO prequalifies 6 treatments for Covid-19 infection. And Tocilizumab is the first monoclonal antibody drug added to the list. WHO prequalified this drug on 11 February 2022.

Tocilizumab drug is a monoclonal antibody that reduces inflammation by blocking the interleukin-6 receptor. Healthcare professionals use this drug to treat arthritis and multiple inflammatory diseases. It does not directly target SARS-COV-2; in the case of Covid-19 infection, the immune system can become hyperactive, resulting in worsening illness. The FDA approved Tocilizumab in 2010.

Prequalification by WHO

WHO Prequalification results from the requirement to ensure a supply of quality-assured health products in low- and middle-income countries. WHO does this by assessing the quality, safety, and efficacy of a wide range of health products to avoid, diagnose and treat priority diseases. Prequalification is an essential service provided for the United Nations and other large procurers of health commodities. Many countries use the WHO prequalified products list for their bulk purchasing of medicines, vaccines, diagnostics, and other critical products.

Clinical trials and results

Tocilizumab is administered intravenously, and in clinical trials of hospitalized patients with COVID-19, Tocilizumab in addition to the usual care patients receive for treatment of COVID-19, which included corticosteroid therapy, was shown to decrease the risk of death through 28 days of follow-up and decrease the amount of time patients remained hospitalized. Tocilizumab also reduces the risk of patients being placed on ventilators or death through 28 days of follow-up. WHO recommends this drug only in severe or critical COVID-19 patients. Only experienced healthcare providers should administer this drug in a monitored clinical setting along with the current standard of care for COVID-19, including oxygen, corticosteroids, and other medications.

For instance, in the RECOVERY trial, 4,116 hospitalized patients with severe COVID-19 pneumonia were randomized to receive either Tocilizumab in addition to regular care (2,022 patients) or regular care alone (2,094 patients). Initially, the endpoint evaluated death through 28 days of follow-up, and the preliminary analysis results were statistically significant. The probability of death by the 28th day was approximately 30.7% for patients receiving Tocilizumab and 34.9% for patients receiving regular care alone. The average time to hospital discharge was 19 days for patients receiving Tocilizumab and more than 28 days for patients receiving routine care alone.