Theratechnologies Inc. (Theratechnologies) (TSX: TH) announced Friday that it has been notified by its partner, TaiMed Biologics, Inc., that the U.S. Food and Drug Administration (FDA) has accepted for review the Biologics License Application (BLA) for ibalizumab as a treatment for multidrug resistant Human Immunodeficiency Virus-1 (MDR HIV-1). If approved, ibalizumab will be the first antiretroviral treatment (ART) with a new mechanism of action to be introduced in nearly 10 years and the only treatment that does not require daily dosing.
“We are excited to be one step closer to potentially bringing an important new treatment, with a new mechanism of action, to patients whose virus has become resistant to therapies in multiple classes and have limited treatment options for the long-term management of their condition,” said Luc Tanguay, President and Chief Executive Officer, Theratechnologies Inc. “The granting of Priority Review status is important since it confirms that, if approved, ibalizumab would represent a significant improvement in the treatment of this serious condition,” added Mr. Tanguay.
The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of January 3, 2018, for the ibalizumab application. Priority Review status accelerates FDA review time from 10 months to a goal of six months from the day of acceptance. In addition, ibalizumab received Breakthrough Therapy designation from the FDA in 2015, which is given if a therapy may provide a substantial improvement over what is currently available to address a serious and life-threatening condition. The FDA also granted Orphan Drug designation in 2014.
The BLA, submitted on May 3, 2017, is based on data from the phase III TMB-301 study, a single arm, 24-week study of ibalizumab plus an optimized background regimen (OBR) in treatment-experienced patients who had high pre-existing levels of drug resistance and advanced clinical disease.
The ibalizumab Expanded Access Program (EAP), or study TMB-311, is ongoing and enrolling patients. For more information about TMB-311 (NCT02707861), please refer to the ClinicalTrials.gov website (www.clinicaltrials.gov[clinicaltrials.gov]) or the study website (www.ibalizumab-eap.com[ibalizumab-eap.com]).
As HIV multiplies in the body, the virus may mutate to produce drug-resistant strains. Viral mutations may mean that HIV medicines that previously controlled a person’s virus are no longer effective, causing treatment to fail. There are approximately 20,000 to 25,000 Americans with HIV-1 that are resistant to at least one drug out of the three different classes of antiretroviral therapies. Up to 12,000 of these patients experience a virological failure over a period of 48 weeks of treatment, requiring their physician to modify their treatment.
Ibalizumab is an investigational humanized monoclonal antibody being developed for the treatment of MDR HIV-1 infection. Unlike other antiretroviral agents, ibalizumab binds primarily to the second extracellular domain of the CD4+ T cell receptor, away from major histocompatibility complex II molecule binding sites. It potentially prevents HIV from infecting CD4+ immune cells while preserving normal immunological function.
Ibalizumab is active against HIV-1 resistant to all approved antiretroviral agents.