Researchers develop once-a-week pill to treat HIV

New Delhi: One of the deadliest diseases to have gripped the world is HIV/AIDS, which has caused the biggest, long-standing challenge for scientists – a vaccine/drug to cure it.

The research on procuring an effective vaccine or a drug is underway and scientists have come quite close to a final result.

Meanwhile, in what can be called a breakthrough, a team of researchers has developed a capsule that can deliver a week's worth of HIV drugs in a single dose.

The advance could make it much easier for patients to adhere to the strict schedule of dosing required for the drug cocktails used to fight the virus, the researchers said.

When infected with the HIV virus, humans cannot produce the required antibodies to kill it, which is why an HIV vaccine has been a challenge to develop.

The new capsule developed by researchers at Massachusetts Institute of Technology (MIT) in the US is designed so that patients can take it just once a week, and the drug will release gradually throughout the week.

This type of delivery system could not only improve patients' adherence to their treatment schedule but also be used by people at risk of HIV exposure to help prevent them from becoming infected, the researchers said.

"One of the main barriers to treating and preventing HIV is adherence," said Giovanni Traverso, a research affiliate at MIT and biomedical engineer at Brigham and Women's Hospital.

"The ability to make doses less frequent stands to improve adherence and make a significant impact at the patient level," said Traverso, senior author of the study published in the journal Nature Communications.

The capsule consists of a star-shaped structure with six arms that can be loaded with drugs, folded inward, and encased in a smooth coating.

After the capsule is swallowed, the arms unfold and gradually release their cargo.

"In a way, it is like putting a pillbox in a capsule. Now you have chambers for every day of the week on a single capsule," Traverso said.

Tests in pigs showed that the capsules were able to successfully lodge in the stomach and release three different HIV drugs over one week, researchers said.

The capsules are designed so that after all of the drug is released, they disintegrate into smaller components that can pass through the digestive tract.

Working with the Institute for Disease Modeling in Washington, the researchers tried to predict how much impact a weekly drug could have on preventing HIV infections.

They calculated that going from a daily dose to a weekly dose could improve the efficacy of HIV preventative treatment by about 20 percent.

When this figure was incorporated into a computer model of HIV transmission in South Africa, the model showed that 200,000 to 800,000 new infections could be prevented over the next 20 years, researchers said.

(With PTI inputs)