A Clinical Study Evaluating the Safety, Tolerability, and Effect on HIV Reservoir of Ibalizumab Combined With Chidamide (a Histone Deacetylase Inhibitor) in People Living With HIV

A Clinical Study Evaluating the Safety, Tolerability, and Effect on HIV Reservoir of Ibalizumab Combined With Chidamide (a Histone Deacetylase Inhibitor) in People Living With HIV

HIV viral reservoirs represent the major barrier to curing AIDS, and effectively reducing viral reservoirs in people living with HIV through different strategies has become a research priority in the HIV field.

Ipilimumab-tovorafenib monoclonal antibody injection (Aituo combination antibody, QL1706) contains two engineered monoclonal antibodies targeting PD-1 and CTLA-4. Chidamide is the first independently developed histone deacetylase inhibitor in China. This study aims to evaluate the safety and efficacy of Aituo combination antibody combined with chidamide in people living with HIV.

This study adopts a modified "1+3+3" dose-escalation design. Initially, one participant will be enrolled at dose level 1 (DL1) for safety observation. If the treatment is well tolerated, the study will proceed to a standard 3+3 design, with sequential dose escalation to DL2 and DL3.

Three dose levels are planned: DL1, the starting dose, consists of ipilimumab-tovorafenib monoclonal antibody injection at 0.3 mg/kg once every 4 weeks ± 1 day for a total of three doses, in combination with chidamide 10 mg orally twice weekly for 12 weeks. DL2 consists of ipilimumab-tovorafenib monoclonal antibody injection at 1 mg/kg once every 4 weeks ± 1 day for a total of three doses, in combination with chidamide 10 mg orally twice weekly for 12 weeks. DL3 consists of ipilimumab-tovorafenib monoclonal antibody injection at 2 mg/kg once every 4 weeks ± 1 day for a total of three doses, in combination with chidamide 10 mg orally twice weekly for 12 weeks.

During dose escalation, progression to the next dose level or discontinuation of escalation will be determined according to the occurrence of dose-limiting toxicities (DLTs). The DLT observation window is 28 days after the first dose. Participants evaluable for DLT are those who complete the observation window or experience a DLT. After completion of dose escalation, the maximum tolerated dose (MTD) will be determined based on safety and tolerability. If the MTD is not reached, DL3 will be selected as the dose for subsequent study.

After determination of the MTD or the subsequent study dose, an additional 11 participants will be enrolled at that dose level to further evaluate safety, tolerability, and preliminary efficacy. The maximum total sample size of the study will be 29 participants.

Inclusion Criteria:

1. Subjects aged 18-65 years.
2. Confirmed HIV infection by both initial screening assay and Western blot (WB) confirmatory test.
3. Receiving a stable ART regimen for at least 6 months.
4. Viral load below the lower limit of detection.
5. CD4+ T-cell count >200 cells/mm³.
6. Voluntarily signed the informed consent form and able to comply with regular follow-up visits, specimen collection, and monitoring/treatment of study-related adverse events.
7. Use effective contraception from 4 weeks prior to study initiation until 4 weeks after study completion.

Exclusion Criteria:

1. Pregnant or breastfeeding women, or women planning to become pregnant during the study observation period.
2. Subjects with poor treatment adherence.
3. Receipt of immunosuppressants, other immunomodulatory agents, or cytotoxic drugs within 6 months prior to screening.
4. Presence of severe underlying cardiac, cerebral, hepatic, renal, or other systemic diseases; neutrophil count <1000/mm³; platelet count <75,000/mm³; allergy to the investigational drug; or other contraindications to treatment.
5. Presence of progressive (or active) malignancy, including but not limited to advanced, metastatic, or unresectable solid tumors or hematologic malignancies.
6. Unwillingness to sign the informed consent form.