ViiV's injectable HIV regimen posts week-96 data for hard-to-treat Africa cohort
IMPALA's week-96 results test whether long-acting cabotegravir plus rilpivirine can hold viral suppression in patients who struggled on daily pills, a population most HIV trials don't enroll.
Executive Summary
- A Phase 3 trial of ViiV Healthcare's long-acting injectable HIV regimen will report two-year results in a population selected specifically because they struggled to stay on daily pills, a group most late-stage HIV trials do not enroll.
- The regimen is already approved for patients who are already virologically suppressed on oral therapy; this trial asks whether it can also work as a rescue option for patients with a documented history of missed doses or lapsed care, a considerably higher bar.
- Long-acting injectable HIV treatment is a mechanism ViiV Healthcare has already established as a commercial reality, so the informative question is not whether the mechanism works but whether it holds up under real-world adherence pressure in a resource-limited setting.
- The trial closed enrollment at its full target with a stable protocol history, giving the week-96 data a completed, undiluted study population to report from.
The trial and its patients
IMPALA (NCT05546242) enrolled 540 adults living with HIV-1 across Uganda, Kenya, and South Africa, all with a documented history of suboptimal adherence or disengagement from oral antiretroviral therapy. That inclusion criterion is the trial's defining feature: participants had detectable viral load despite prior treatment, had lapsed from care for more than four weeks, or had failed to link to care within three months of diagnosis. The trial randomized these patients to long-acting cabotegravir plus rilpivirine, given by intramuscular injection every two months, against a comparator arm of oral dolutegravir, lamivudine, and tenofovir disoproxil fumarate. The primary registered endpoint is HIV-1 viral load at 12 months; the week-96 data being presented extend that endpoint to a longer follow-up window. NCT05546242Improving HIV-1 Control in Africa with Long Acting AntiretroviralsNCT05546242
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What's being presented
ViiV Healthcare said week-96 results from IMPALA, led by the London School of Hygiene and Tropical Medicine, "will provide new insights into the use of CAB+RPV LA in adults living with HIV with prior adherence challenges in sub-Saharan Africa, including treatment outcomes over time," set for late-breaker presentation at the 26th International AIDS Conference in Rio de Janeiro from July 26-31, 2026. The company is presenting the data alongside a separate late-breaking readout from the LATA study in virologically suppressed adolescents and OPERA real-world data comparing the same injectable regimen against daily oral bictegravir combinations, giving the injectable platform three separate readouts at the same meeting. ViiVViiV Healthcare to present phase IIIb data comparing Dovato with Biktarvy in treatment-naïve adults; alongside INSTI-powered long-acting injectable innovation at AIDS 2026Jul 21, 2026
Operational context
IMPALA enrolled to its full target of 540 patients with no shortfall against target, moved to Active, not recruiting status once enrollment completed in September 2024, and has recorded a single primary completion date amendment, pushing the date five months from November 2024 to April 2025. The protocol has been amended for eligibility criteria three times and its primary outcome measure once, but the primary outcome itself was not altered after the trial's completion date, and enrollment held flat at the target rather than being cut. That is a routine profile for a trial of this size and duration. NCT05546242Improving HIV-1 Control in Africa with Long Acting AntiretroviralsNCT05546242
The competitive frame
Cabotegravir and rilpivirine are already approved as a complete regimen for patients who are virologically suppressed and switching from oral therapy, sold as Cabenuva in the United States. IMPALA does not test a new mechanism; it tests whether that established regimen also works in patients who were not stably suppressed on oral therapy to begin with, a distinct and harder clinical question. The nearest mechanism comparator in active development is Gilead Sciences' bictegravir-based regimens, also integrase inhibitors, tested largely in treatment-naive or already-suppressed populations rather than in patients selected for prior nonadherence. Within the same injectable class, ViiV Healthcare is also running ultra-long-acting formulations of cabotegravir and rilpivirine dosed less frequently, meaning the sponsor's own next-generation candidates sit downstream of whatever durability signal IMPALA establishes in this harder-to-reach population. ViiVViiV Healthcare to present phase IIIb data comparing Dovato with Biktarvy in treatment-naïve adults; alongside INSTI-powered long-acting injectable innovation at AIDS 2026Jul 21, 2026
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.