Pfizer plans to begin testing of its arthritis medication Xeljanz (tofacitinib) in COVID-19 patients in Italy this week.
Xeljanz is a janus kinase (JAK) inhibitor. It is an inhibitor of the enzymes janus kinase 1 and janus kinase 3. Inhibiting these enzymes inhibits the production of inflammatory mediators. Thus, it may help severely ill COVID-19 patients who suffer from severe cytokine release syndrome, otherwise known as a “cytokine storm.” Severe cytokine release syndrome is essentially a runaway immune response which can kill patients via an uncontrolled inflammation response.
An arthritis medication of a different class, Actemra (tocilizumab), saw a 95% success rate in treating severely ill COVID-19 patients in China. Actemra may treat severely ill COVID-19 patients in a similar manner to Xeljanz: by reducing inflammation. Actemra inhibits levels of the Interleukin 6 (IL-6) protein, a protein which causes inflammation. The FDA recently approved a randomized, double-blind, placebo-controlled phase III study into Actemra’s efficacy and safety regarding COVID-19 treatment, and Chugai Pharmaceutical plans on conducting a clinical trial in Japan regarding Actemra for COVID-19 treatment.
Meanwhile, a new clinical trial has begun in Spain which will investigate whether Truvada (emtricitabine/tenofovir disoproxil fumarate) can prevent COVID-19 infection.
“Existing recent and scarce literature shows that RNA synthesis nucleos(t)ide analogue inhibitors, acting as viral RNA chain terminators, like [tenofovir disoproxil fumarate], abacavir or lamivudine, amongst others, could have an effect against SARS-CoV-2 infection,” the abstract for the trial says.
Facebook recently began deleting misleading ads about Truvada from its website. The ads misleadingly implied that those taking Truvada for PrEP faced an equivalent risk of serious side effects as those taking Truvada for treatment of existing HIV infections. TDF medications such as Truvada were linked to decreased bone density and osteoporosis in a 2010 study and kidney damage and renal failure in a 2018 study. However, a 2017 study demonstrated that those treating HIV infections with TDF drugs saw a higher risk of kidney damage and bone density loss than those using TDF drugs as PrEP.
The U.S. Food and Drug Administration (FDA) said in February 2019 that an increased risk of blood clots in the lungs and death could be associated with Xeljanz when taken two times per day at a 10 mg dosage. The FDA approved a Boxed Warning for the drug in July 2019. That warning said Xeljanz being taken twice per day for ulcerative colitis could be associated with an increased risk of blood clots or death.