US biotech group to trial Covid-19 pill for use at home

A US biotech company is to start trialling a coronavirus pill on patients who test positive for Covid-19 but do not require hospitalisation, in one of the first experiments of its kind.

Ridgeback Biotherapeutics told the Financial Times that the drug, codenamed EIDD-2801, had cleared Phase 1 safety trials and that the company would now start recruiting patients for the next stage of testing to determine whether it could fight the virus.

The trial is one of the first studies of a pill that could be prescribed not only to very sick hospitalised patients but also to those who test positive and are well enough to quarantine at home.

If the drug is ultimately successful, it would offer a simple twice-a-day tablet that could be given to millions of patients who test positive, preventing them from becoming seriously ill and helping them recover more quickly.

The trial comes as drugmakers rush to research potential treatments and vaccines for the virus, which has killed more than 450,000 people worldwide, according to Johns Hopkins University.

However, many of the other medicines being trialled have focused on treating patients in hospital, such as the steroid dexamethasone and Gilead’s remdesivir, which is given to patients via an intravenous drip.

Dr Wayne Holman, co-founder of Ridgeback, said if the drug could “eliminate the virus more quickly than placebo” then it might be able to “halt the disease in the early stages, potentially reduce the time during which patients are infectious to others and change the course of the pandemic”.

Ridgeback recently signed a partnership deal with Merck, the large US pharmaceuticals group, but is developing the medicine independently pending regulatory clearance of the transaction. The drug was discovered by researchers at Emory University in Atlanta.

Ridgeback said it would also start testing the drug in a second Phase 2 study focused on sicker patients in hospital. About 100 patients will be enrolled in the two trials, which are being conducted by scientists at hospitals and universities in North Carolina and Baltimore.

The primary measure of success will be whether patients on EIDD-2801 test negative for the virus within a shorter timeframe than those receiving the dummy pill.

Ridgeback said it had started manufacturing “hundreds of thousands of doses” of the drug without knowing whether it would succeed in the final Phase 3 stage of testing.

“To ensure that EIDD-2801 is rapidly available for patients if the medicine proves to be an effective treatment . . . Ridgeback has been manufacturing doses at its own risk and expense,” the company said.

It added that it planned to “produce as many as a million treatment courses” by the autumn, “even in advance of definitive clinical data”.

The drug works by planting molecules in the virus’s RNA genetic material that then trigger a cascade of mutations, which ultimately kill it.

A potential problem with EIDD-2801 is that tests on bacteria show that it can cause mutations in the DNA of human patients. However, Ridgeback and Merck have played down the possible dangers, pointing out that the medicine will only be prescribed to patients for a short, five-day course.

In an interview following the partnership deal, Merck chief executive Ken Frazier said: “It can be given earlier in the disease process, obviously, than a medicine that has to be used by IV injection. Our goal is to find something that can be used early.”