BACKGROUND: The HIV-1 reservoir is a major barrier to curative strategies. Inflammation is an important factor for HIV-1 reservoir persistence. Lenalidomide regulates inflammatory cytokines efficiently. We examined whether lenalidomide could inhibit HIV-1 transcription and reduce systemic inflammation in people living with HIV. METHODS: Lenalidomide was administered orally for 48 weeks to patients with HIV-associated cryptococcal meningitis (HIV-CM). A HIV-1 latency model was treated with or without lenalidomide ex vivo for 5 days. The primary endpoints were change in HIV reservoir markers and inflammatory cytokines in both the cohort and cell model. RESULTS: Thirteen participants were enrolled from May 2019 to September 2020. The median change in cell-associated (CA) HIV RNA between baseline and 48 weeks was 0.81 log10 copies/million peripheral blood mononuclear cells (PBMCs). The CA HIV RNA decreased significantly in the cohort (P = 0.021). Serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) gradually diminished with lenalidomide treatment until 48 weeks (P = 0.007, P = 0.014, respectively). C-reactive protein/IL-6/TNF-α and CA HIV RNA were significantly correlated (P = 0.0027, 0.0496, and 0.0346, respectively). Lenalidomide also significantly decreased HIV core P24 (P = 0.0038) and CA HIV RNA in CD8-depleted PBMCs (P = 0.0178) ex vivo. TNF-α and IL-6 were significantly reduced in the CD8-depleted PBMC supernatant (P = 0.004, P < 0.0001, respectively) while IL-10 levels increased significantly on lenalidomide compared to no-lenalidomide treatment (P < 0.0001). CONCLUSIONS: Lenalidomide was preliminarily confirmed to reduce the level of cell- associated HIV RNA and improve persistent inflammation in patients with HIV-Associated cryptococcal meningitis, which was a potential intervention for clinical use to inhibit viral transcription of the HIV-1 reservoir and reduced HIV-related inflammation in HIV-1 patients during ART.