Covid Antiviral Pills Offer Hope as Omicron Looms
Positive data in a phase II clinical trial could lead to US approval
A generic version of HIV drugs known as Omicron Lo with a prescription treatment and precautionary eye drops appears to be an effective alternative to expensive, brand-name drugs that is cheaper and safer, new research shows.
The results from the trial using three types of eye drops in association with a daily drug combination for a group of HIV-infected patients were encouraging, according to lead author Dr Muthung Lepcha, of Cardiff University.
“This study showed that the Omicron antiretroviral pill combination was well tolerated and had moderate-to-high anti-HIV efficacy,” said Lepcha. “Importantly, no serious adverse events were reported.”
Omicron Lo pills combine two anti-HIV drugs, known as nevirapine and lamivudine, which help the immune system fight the virus. Lamivudine alone and pre-exposure prophylaxis (PrEP) with pre-exposure prophylaxis – also known as nalivaxine and nevirapine-rapid-acting antiretroviral therapy (Rapt), a combination of nevirapine and lamivudine – are currently the main HIV drugs used to fight the infection.
Testing was carried out on 1,054 HIV-infected patients who were randomly assigned to take either the Omicron pill combination every day or placebo.
Patients who took the Omicron combination had a better response to treatment, the researchers found. They also had a lower rates of adverse reactions, including mouth ulcers and cysts.
However, there was no improvement in viral load levels among patients who took the placebo. The researchers say they are conducting a larger trial to confirm the results in higher patient numbers.
Approval in the US, where the study was conducted, for the use of Omicron Lo’s combination for HIV prevention will depend on results from a second trial that will be based on patient data from the existing study, the scientists said. If the safety and efficacy of the combination are shown to be comparable to the use of either of the two treatment methods currently used in HIV prevention, prescription availability could be accelerated.
If a generic version of anti-HIV drugs are ultimately approved, it could save money and boost HIV/AIDS treatment and care, said Lepcha. Currently a third of all HIV patients in developing countries do not receive treatment, according to international experts.
Dr John Gleason, of Centre for HIV and TB Prevention at St Michael’s Hospital in Toronto, who was not part of the study, said: “It is a move forward for the emerging option for HIV prevention.”
However, other experts were sceptical, as a generic version of Omicron Lo could “greatly diminish the availability and affordability of virology therapy”, reported the Liverpool School of Tropical Medicine. This is likely to limit anti-HIV treatment, they said.
Moreover, experts said the trials only compared high doses of a drug already widely used. “Assuming further trials will be able to show safety and efficacy beyond these doses, the [specimens of the study] regimen would still represent a very high (10mg/mL), risk/benefit ratio,” said Professor Brendan Veeen, HIV expert and consultant clinical virologist at Imperial College Healthcare NHS Trust in London.
Results of the study were published online in the journal, The Lancet, on Monday.