PTC Therapeutics taps experimental cancer drug for new COVID-19 trial

PTC Therapeutics is throwing its hat in the ring for a potential reworked pipeline med against COVID-19.

The biopharma, which has been focused on rare diseases, is tapping its early-stage cancer drug, currently in a test for certain leukemias, to see whether it can help patients afflicted with the disease.

It is any day now kick-starting a phase 2/3 trial of PTC299, an oral small molecule that inhibits the cellular enzyme dihydroorotate dehydrogenase (DHODH), in the hopes it can dampen viral replication and uncontrolled inflammatory response.  

The randomized, double-blind, placebo-controlled study will come in two stages and is set to start in the U.S. in the “coming days,” with additional tests asked for in Spain and filings planned in Europe, Brazil and Australia.

The first stage of the test is made up of 40 patients, followed by a larger cohort of around 340 patients. The primary objective is to assess how well PTC299 works compared with placebo as measured by time to respiratory improvement in adults hospitalized with COVID-19.

“We are excited about the potential of PTC299 to be part of the solution to this unprecedented global public health crisis and have made it a high priority within our organization,” said Stuart Peltz, Ph.D., CEO at PTC.

“The fact that PTC299 inhibits DHODH uniquely addresses the two key issues of COVID-19, namely reducing the high viral replication and also selectively attenuating the immune response caused by the uncontrolled cytokine storm resulting from the SARS-CoV-2 infection.”

There are two drugs, originally intended for other diseases, now greenlighted for COVID-19: Gilead Sciences' remdesivir, which had been tested for Ebola but is now approved to help COVID-19 patients leave the hospital earlier, and old steroid dexamethasone, which was approved in the U.K. this week after showing it could cut deaths in some hospitalized patients (though both drugs have their caveats and pitfalls).

There are a number of other drugs being assessed for the disease, including treatments that use recovered patients’ antibodies to help kill off the disease and reworked arthritis drugs, as well more than 130 vaccines in development.