The persistence of latent HIV-1 reservoirs remains a major barrier to achieving a cure for HIV. While latency-reversing agents (LRAs) have been extensively studied, latency-promoting agents (LPAs) off Show more
The persistence of latent HIV-1 reservoirs remains a major barrier to achieving a cure for HIV. While latency-reversing agents (LRAs) have been extensively studied, latency-promoting agents (LPAs) offer a complementary strategy to silence viral transcription and prevent immune activation. Here, we propose that modulation of IRF7-driven transcription may represent a novel approach to control HIV-1 latency, by characterizing the role of the Janus kinase 2 inhibitor (JAK2i) pacritinib as a novel latency-promoting agent (LPA). The impact of JAK2i on HIV-1 reactivation, immune activation, and IRF7 expression were evaluated in lymphoid and myeloid HIV-1 latency models, as well as Pacritinib effectively suppressed HIV-1 latency reversal induced by LRAs without triggering immune activation. Mechanistically, pacritinib downregulated IRF7 expression at both transcript and protein levels, correlating with reduced HIV-1 transcription. Overexpression of IRF7 restored LTR transactivation, confirming its central role in HIV-1 transcription and latency. Co-immunoprecipitation assays revealed a direct interaction between IRF7 and the viral transactivator Tat. Furthermore, pacritinib selectively inhibited multiply spliced HIV-1 transcripts, suggesting a blockade at late transcriptional stages. Pacritinib acts as a potent LPA by silencing HIV-1 transcription through IRF7 downregulation, supporting a promising "block and lock" strategy for functional cure approaches. Targeting IRF7 may enable durable suppression of the viral reservoir without immune activation, supporting the development of "block and lock" therapies. Show less
Genetic alterations activating the MAPK pathway are common in non-small cell lung cancer (NSCLC). Patients with NSCLC may benefit from treatment with the pan-RAF inhibitor naporafenib (LXH254) plus th Show more
Genetic alterations activating the MAPK pathway are common in non-small cell lung cancer (NSCLC). Patients with NSCLC may benefit from treatment with the pan-RAF inhibitor naporafenib (LXH254) plus the ERK1/2 inhibitor rineterkib (LTT462) or MEK1/2 inhibitor trametinib. This first-in-human phase 1b dose-escalation/dose-expansion study investigated the combinations of naporafenib (50-350 mg once daily [QD] or 300-600 mg twice daily [BID]) with rineterkib (100-300 mg QD) in patients with KRAS-/BRAF-mutant NSCLC and naporafenib (200 mg BID or 400 mg BID) with trametinib (0.5 mg QD, 1 mg QD or 1 mg QD 2 weeks on/2 weeks off) in patients with KRAS-/BRAF-mutant NSCLC and NRAS-mutant melanoma. The primary objectives were to identify the recommended dose for expansion (RDE) and evaluate tolerability and safety. Secondary objectives included antitumor activity and pharmacodynamics. Overall, 216 patients were treated with naporafenib plus rineterkib (NSCLC: n = 101) or naporafenib plus trametinib (NSCLC: n = 79; melanoma: n = 36). In total, 10 of 62 (16%) patients experienced at least one dose-limiting toxicity. The RDEs were established as naporafenib 400 mg BID plus rineterkib 200 mg QD, naporafenib 200 mg BID plus trametinib 1 mg QD and naporafenib 400 mg BID plus trametinib 0.5 mg QD. The most frequent grade ≥ 3 treatment-related adverse event was increased lipase (8/101 [7.9%] patients) for naporafenib plus rineterkib and rash (22/115 [19.1%] patients) for naporafenib plus trametinib. Among patients with NSCLC, partial response was observed in three patients (one with KRAS-mutant, two with BRAF Both naporafenib combinations had acceptable safety profiles. Antitumor activity was limited in patients with NSCLC, despite the observed on-target pharmacodynamic effect. gov identifier: NCT02974725. Show less