Roche's attempt to retool its rheumatoid arthritis drug Actemra/RoActemra to treat patients hospitalised with severe Covid-19-related pneumonia has failed in a late-stage trial, the Swiss company said on Wednesday.
Roche launched the 330-patient trial in March as it joined other pharmaceutical companies seeking to re-purpose existing medicines to fight the pandemic.
The "COVACTA trial did not meet its primary end-point of improved clinical status in patients with Covid-19 associated pneumonia, or the key secondary end-point of reduced patient mortality," Roche said.
The news follows an Italian study that showed the drug failed to help patients with early-stage Covid-19 pneumonia.
Roche shares were little changed.
"For Covid-19 patients in need of an effective treatment, today's news is disappointing. From an investment perspective, we never assumed a pandemic-driven long-term increase of Actemra revenues," Bank Vontobel analysts said.
Pharmaceutical companies have been racing to develop treatments against the Covid-19 pandemic that has claimed nearly 660,000 lives and crippled economies.
Around 150 companies are working on vaccines, although their first use cannot be expected until early 2021, the World Health Organization said last week.
Companies, meanwhile, have been trying to find ways to use existing drugs to treat Covid-19 patients.
India's Glenmark Pharmaceuticals Ltd for example, has been trialling its anti-flu drug favipiravir on patients with mild to moderate infections.
Roche is also testing if Actemra mixed with Gilead Sciences Inc's anti-viral treatment remdesivir works better against severe Covid-19 pneumonia than remdesivir or Actemra alone.
So far, remdesivir has been shown to help speed up recovery for Covid-19 patients, while the older generic steroid dexamethasone in a British-led trial reduced death rates by around a third among those with the most severe infections.
Roche said the Gilead collaboration was ongoing and it would continue to examine how Actemra could be used to treat Covid-19-related pneumonia. But it would not be applying for regulatory approval for use of the drug on its own against the condition.
The European Commission had struck a deal with Roche to secure supplies of RoActemra, but it was too early to comment on the commercial impact on the negative results of the COVACTA trial, a Roche spokesman said.
The Commission was not immediately available to comment.
In the COVACTA trial, there was no difference in mortality rates after four weeks between patients who took Actemra/RoActemra and those who did not.
Although the drug reduced the time it took to discharge patients by an average of eight days, this was not considered significant as the main goal was not met.
"People around the world are waiting for further effective treatment options for Covid-19 and we are disappointed that COVACTA did not demonstrate a benefit for patients in either clinical status or mortality at week four," Levi Garraway, Roche's chief medical officer, said.
"We will continue to generate evidence to provide a more complete understanding of Actemra/RoActemra in Covid-19 associated pneumonia."