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Our Stories

St. Michael’s clinical trial tests possible HIV prevention drug

Toronto, June 2, 2014

By Geoff Koehler

Dr. Darrell Tan
Dr. Darrell Tan

It’s often said that an ounce of prevention is worth a pound of cure.

But Dr. Darrell Tan would like to test whether prevention and treatment could be the same thing when it comes to HIV infection.

St. Michael’s is leading a clinical trial that will evaluate how best to deliver a daily pill, originally marketed as a treatment for HIV infection. The study will look at HIV-prevention outcomes of high-risk groups’ real world use this drug.

This is the first trial in Toronto looking at HIV pre-exposure prophylaxis, commonly known as PrEP.

“Our research is targeted toward helping those who are at high risk of contracting HIV, particularly gay, bisexual and other men who have sex with men,” said Dr. Tan, a clinician scientist in infectious diseases at St. Michael's Hospital.

An estimated 71,300 people are living with HIV in Canada – 25 per cent of whom are unaware of their infection.

The drug tested in this trial, Truvada, was approved for daily preventative use in the U.S. in 2012.

Despite its promise, PrEP is not without its controversy. When used as a preventative measure, the $900-per-month prescription medication is taken by people don’t have HIV – which raises questions about its risk and benefits. Public health officials have also raised concerns that overuse could potentially increase drug-resistance. Finally, some people fear that if PrEP is shown to effectively protect individuals against HIV, people might take more risks when it comes to exposure, either intentionally or subconsciously.

Dr. Tan is aware of such concerns and acknowledged that these are exactly the type of research questions that will be addressed in his trial.

“PrEP is not a magic bullet,” said Dr. Tan. “It might be an arrow in the quiver in the fight against HIV infection but we need to determine how best to deliver PrEP to maximize its potential to prevent HIV infection first.”

This pilot trial will follow gay and bisexual men for one year. Dr. Tan hopes the pilot will expand nationally.

About St. Michael's Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

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