Dr. Christian Marsolais reports

THERATECHNOLOGIES PRESENTS ENCOURAGING VIROLOGIC SUPPRESSION DATA FROM THE PROMISE-US TRIAL OF IBALIZUMAB AT CROI

Theratechnologies Inc. has presented data from a real-world, observational, registry study demonstrating the efficacy and safety of ibalizumab in reducing HIV RNA to undetectable levels in heavily treatment-experienced (HTE) patients with multidrug-resistant HIV.

In a poster session at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco, Calif., investigators from the prospective observational study of multidrug-resistant patient outcomes with and without ibalizumab in a real-world setting: United States (Promise-U.S.) reported that patients treated with regimens containing ibalizumab achieved undetectable HIV viral load levels at similar rates as those receiving non-ibalizumab-containing regimens, despite displaying characteristics indicative of more severe HIV disease at baseline.

"The availability of long-term injectable therapies has not eliminated the phenomenon of multidrug resistance, and heavily treatment-experienced people with HIV deserve fully suppressive anti-retroviral regimens that can help them establish and maintain virologic control," stated presenting author Dr. Smitha Gudipati, MD, an infectious disease specialist at Henry Ford Hospital in Detroit, Mich. "We are therefore encouraged to see such impressive reductions in viremia in patients whose regimens include ibalizumab, despite having lower CD4 counts and higher viral loads at baseline than the non-ibalizumab control group."

Theratechnologies previously announced the study design and baseline characteristics of participants in Promise-U.S. (ClinicalTrials.gov identifier: NCT05388474), a phase 4, multicentre, retrospective and prospective, observational, non-interventional registry study. The trial is designed to assess risk factors and predictors of virologic and immunologic response in HTE people with HIV (PWH) and specific subpopulations. Its primary objective is to evaluate the long-term efficacy and durability of ibalizumab, a CD4-directed postattachment inhibitor of HIV, in combination with other anti-retroviral therapies by comparing the clinical outcomes of patients receiving ibalizumab (Cohort 2) versus matched patients not receiving ibalizumab (Cohort 1).

At CROI, the Promise-U.S. investigators presented an interim, unmatched subgroup analysis comprising 112 participants, of whom 70 were enrolled in Cohort 1 and 42 in Cohort 2. At baseline, 27 of participants in Cohort 1 and 25 in Cohort 2 were viremic, defined as viral load above 50 RNA copies per millilitre (39 per cent and 57 per cent, respectively; p equal to 0.0279). Three-quarters (74 per cent) of participants in Cohort 1 who had baseline viremia had more than 200 CD4 T-cells per cubic millimetre at baseline, compared with only 44 per cent of those in Cohort 2 who were viremic at baseline (p equal to 0.0376).

Among those with baseline viremia, 50 per cent of Cohort 1 participants and 47 per cent in Cohort 2 achieved undetectable viral load (less than or equal to 50 RNA copies copies per millilitre) after six months of treatment (p equal to 0.873). At 12 months, viral load was undetectable in 53 per cent of Cohort 1 participants and in 42 per cent of those in Cohort 2 (p equal to 0.0.524). Ibalizumab was well tolerated with no infusion reactions reported and no discontinuation of treatment by participants in Cohort 2 due to a treatment-emergent adverse event.

"The Promise-U.S. trial is the first registry to capture long-term clinical outcomes for highly treatment-experienced patients with multidrug-resistant HIV in a real-world setting and in the U.S. specifically," commented Dr. Christian Marsolais, PhD, senior vice-president and chief medical officer of Theratechnologies. "The data presented today suggest that ibalizumab can be a critical component of therapeutic regimens in the modern anti-retroviral era. We look forward to validating these interim findings as we continue to enroll and monitor patients in this ongoing study."

About Theratechnologies Inc.

Theratechnologies is a specialty biopharmaceutical company focused on the commercialization of innovative therapies that have the potential to redefine standards of care.

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