The long-acting injectable HIV medication ibalizumab has concluded its Phase Three trials, providing further proof that the drug could be a lifesaving game changer for those fighting multi-drug resistant strains of HIV. The U.S. Food and Drug Administration has declared ibalizumab a “breakthrough therapy,” a designation that speeds up the approval process for new therapies treating serious and life-threatening conditions, when they may provide a substantial improvement over what is currently available. Having cleared the last regulatory hurdle, Theratechnologies Inc has begun recruiting participants for an “expanded access study,” which will give needy patients (who didn’t qualify for the clinical trial) access to the new drug while it’s awaiting official FDA approval.

Earlier findings showed the drug, developed by Theratechnologies Inc., was effective in significantly decreasing viral loads after just the first week of treatment. Now we know that those results continued — and even improved — over the course of the study. Forty people with multi-drug resistant strains of HIV participated in the study, where they were either given injections of 2,000 mg of ibalizumab in addition to their (failing) antiretroviral therapies, or ibalizumab with no additional antiretrovirals at all.

In the first week of treatment, 83 percent of participants saw a decrease in their viral loads, with 60 percent having a decrease above 1.0 log10. After the full 24 weeks of treatment, the mean reduction in viral load increased to 1.6 log10 and 48 percent of participants experienced a viral load reduction of more than 2.0 log10.

Dr. Jacob Lalezari, the medical director of Quest Clinical Research, explains a “one log decrease in viral load represents a 90 percent decrease in virus.”

While the success of ibalizumab isn't enough to promote it as a stand-alone therapy, as part of a cocktail with other drugs it will offer effective treatment — especially considering how previous treatment attempts have failed those with multi-drug resistant HIV. (Find out everything you need to know about drug resistance here.)

Study participants weren't just resitant to a single HIV therapy, but showed resistance to nucleoside reverse transcriptase inhibitors (like Viread), non-nucleoside reverse transcriptase inhibitors (like Rescriptor), and protease inhibitors (like Lexiva). More than 60 percent also had resistance to at least one integrase inhibitor (like Insentress). Finally, 50 percent of participants had a strain of HIV that has developed resistance to all available medications from at least three classes of antiretroviral drugs.

At the end of the treatment, 43 percent of study participants experienced viral suppression enough to have undetectable viral loads. That’s a huge success given that the .6 percent of all new HIV cases who are resistant to three classes of drugs, previously had, as Lalezari says, “limited or no remaining options to treat their infection.” Because drug resistant strains can also be transmitted to others, there has been a lot of pressure for new therapies like ibalizumab.

“If approved by the FDA, [it] would be the first long-acting biologic to show such efficacy in patients with highly resistant HIV-1,” says Lalezari, who adds that ibalizumab could “change the way multi-drug resistant HIV is managed in the future,” particularly because the medication will be the first long acting non-oral therapy approved for treating HIV.

As renowned HIV doctor Dr. David Ho told the 2016 U.S. Conference on AIDS, “Injectables are the future of HIV treatment,” because they take the issue of adherence out of the picture. You can’t forget to take a pill when you’re getting a regular shot at your doctor’s office instead.