An antiviral drug combination touted as a potential COVID-19 treatment did not improve patients’ chances of survival, researchers at the University of Oxford announced Monday.  

The drug Kaletra, which uses a combination of lopinavir and ritonavir, is typically used to treat HIV. 

“The results from this trial, together with those from other large randomized trials, should inform revisions to (current) guidelines and changes to the way individual patients are treated,” Martin Landray, deputy chief investigator for the trial, said in a statement. 

Lopinavir-ritonavir made no difference in short-term mortality rates, hospital stay lengths or illness progression to ventilation. The results do not include patients on ventilators because of how difficult it is to administer drugs to them. 

The results were released as part of Oxford’s RECOVERY trial, a massive randomized trial that includes over 11,800 patients from across Britain to simultaneously evaluate a range of proposed COVID-19 treatments. In total, 1,596 patients were treated with lopinavir-ritonavir, and 3,376 received standard care. The researchers announced the results after review by an independent committee. 

The trial confirmed a smaller study published in March in the New England Journal of Medicine, which also concluded that lopinavir-ritonavir did not help COVID-19 patients. 

Earlier this month, the Oxford trial published results showing that the anti-malarial drug hydroxychloroquine was ineffective as a COVID-19 treatment. U.S. President Donald Trump was a strong advocate for the drug’s use and revealed in May he had been taking it as a preventative measure. 

There are nearly 260 treatments and over 170 vaccines currently in development, according to estimates from the Milken Institute. There are no widely approved treatments or vaccines, although China made headlines Sunday for approving a vaccine candidate for military use.