Theratechnologies Reveals PROMISE-US Trial Design for Ibalizumab in Multidrug-Resistant HIV Patients

Theratechnologies Inc., a biopharmaceutical firm specializing in innovative therapies, presented the findings from the study titled "Prospective Observational Study of Multidrug-Resistant Patient Outcomes with and without Ibalizumab in a Real-World Setting: United States" (PROMISE-US) at IDWeek 2024 in Los Angeles. The study aims to bridge a significant gap in understanding the long-term clinical outcomes for individuals with HIV who have extensive treatment histories and are experiencing multidrug resistance.

The researchers revealed that ibalizumab, a CD4-directed post-attachment inhibitor of HIV, is more frequently selected for heavily treatment-experienced (HTE) patients with lower CD4 counts and higher viral loads compared to other regimens. Despite being used in these advanced cases, ibalizumab showed commendable durability, with many patients continuing the therapy for over 24 months.

Dr. Charlotte-Paige Rolle, the Director of Research Operations at the Orlando Immunology Center, emphasized the challenge of achieving and maintaining virologic control in HIV patients due to extensive prior exposure to antiretroviral therapies. This necessitates the need for more treatment options and understanding patient responses. PROMISE-US was thus designed to compare the long-term efficacy and safety of ibalizumab-based regimens with other treatments in a real-world setting for HTE individuals.

PROMISE-US, marked by the identifier NCT05388474 on ClinicalTrials.gov, is a phase 4, multicenter, retrospective and prospective, observational, non-interventional registry study. It aims to identify risk factors and predictors of virologic and immunologic response in HTE individuals, including capturing patient-reported outcomes like treatment satisfaction and adherence.

The primary goal of the study is to evaluate the long-term efficacy and durability of ibalizumab in combination with other antiretroviral (ARV) therapies by comparing clinical outcomes between patients receiving ibalizumab (Cohort 2) and matched patients not receiving the drug (Cohort 1). As of November 2023, 114 participants were enrolled, with 70 in Cohort 1, 42 on ibalizumab, and two screen failures. Baseline characteristics such as race, ethnicity, sex, gender, and time since diagnosis were well matched between the cohorts. Ibalizumab use was linked with patients who had higher viral loads and declining CD4 T cells.

Researchers also examined the use of the capsid inhibitor lenacapavir in HTE patients in combination with ibalizumab. This subset exhibited the highest viral loads and lowest CD4 counts at baseline, though the sample size was small (n=12). By the time of analysis, 80% of participants (n=21) in Cohort 2 had remained on ibalizumab for over 12 months. The therapy was well tolerated with no reported infusion reactions.

Christian Marsolais, Senior Vice President and Chief Medical Officer of Theratechnologies, highlighted the increasing focus on multidrug resistance among HIV researchers and clinicians. The continuous analysis of data from PROMISE-US is aimed at understanding the long-term safety and efficacy of ibalizumab, particularly its compatibility with long-term injectable therapies. Marsolais also noted the study's significance in understanding the factors that contribute to maintaining virologic response in HTE individuals, who have a high unmet need for effective antiretroviral therapy. He expressed pride in being the first company to establish a registry capturing long-term clinical outcomes for patients with multidrug-resistant HIV-1 in a real-world setting, with anticipation of sharing further data from the ongoing study.

IDWeek 2024 serves as the annual joint meeting for several prestigious organizations involved in infectious diseases, including the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists.

Theratechnologies focuses on developing and commercializing breakthrough therapies to address unmet medical needs in the biopharmaceutical sector. Further information about the company and its endeavors can be accessed on various regulatory and information platforms.