Widespread uptake of pre-exposure prophylaxis in gay and bisexual men in NSW has resulted in a dramatic and sustained reduction in HIV incidence, a landmark Australian study shows.

The trial, which recruited nearly 10,000 men who have sex with men (MSM), provides real-world evidence that daily pre-exposure prophylaxis (PrEP) is close to 100% effective, the researchers say.

Originally planned for just 3700 MSM, the Expanded PrEP Implementation in Communities-NSW (EPIC-NSW) study dispensed the medication to participants for free between March 2016 and April 2018 when it became PBS-listed.

Lead researcher Professor Andrew Grulich, head of the HIV epidemiology and prevention program at UNSW Sydney’s Kirby Institute, said it was reassuring that the cost of accessing PrEP “had virtually no impact” on HIV transmission in the cohort.