Despite the success of combined antiretroviral therapy (cART) increasing the survival rate in human immunodeficiency virus (HIV) patients, low levels of viremia persist in the brain of patients leading to glia (microglia and astrocytes)-induced neuroinflammation and consequently, the reactivation of HIV and neuronal injury. Here, we tested the therapeutic efficacy of a Low-Density Lipoprotein Receptor-Related Protein 1 (LRP-1) agonistic small peptide drug (SP16) in attenuating HIV replication and the secretion of inflammatory molecules in brain reservoirs. SP16 was developed by Serpin Pharma and is derived from the pentapeptide sequence of the serine protease inhibitor alpha-1-antitrypsin (A1AT). The SP16 peptide sequence was subsequently modified to improve the stability, bioavailability, efficacy, and binding to LRP-1; a scavenger regulatory receptor that internalizes ligands to induce anti-viral, anti-inflammatory, and pro-survival signals. Using glial cells infected with HIV, we showed that: (i) SP16 attenuated viral-induced secretion of pro-inflammatory molecules; and (ii) SP16 attenuated viral replication. Using an artificial 3D blood-brain barrier (BBB) system, we showed that: (i) SP16 was transported across the BBB; and (ii) restored the permeability of the BBB compromised by HIV. Mechanistically, we showed that SP16 interaction with LRP-1 and binding lead to: (i) down-regulation in the expression levels of nuclear factor-kappa beta (NF-κB); and (ii) up-regulation in the expression levels of Akt. Using an in vivo mouse model, we showed that SP16 was transported across the BBB after intranasal delivery, while animals infected with EcoHIV undergo a reduction in (i) viral replication and (ii) viral secreted inflammatory molecules, after exposure to SP16 and antiretrovirals. Overall, these studies confirm a therapeutic response of SP16 against HIV-associated inflammatory effects in the brain.

Predominant inflammatory immunological patterns as well as the depletion of CD4⁺ T cells during nonalcoholic fatty liver disease (NAFLD) are reported to be associated with the progression of hepatocellular carcinoma (HCC). Here, we report that an LRP-1 agonistic peptide, SP16, when administered during advanced NAFLD progression, restored the depleted CD4⁺ T cell population but did not significantly affect the inflammatory immunological pattern. This data suggests that restoration of CD4⁺ T cells without modulation of the hepatic immunological pattern is not sufficient to prevent HCC. However, SP16 administered early during NAFLD progression modulated the inflammatory profile. Future studies will determine if regulation of the inflammatory immune response by SP16 early in NAFLD progression will prevent HCC.

Background: Cardiac surgery using cardiopulmonary bypass uses controlled hypoperfusion which leads to relative organ damage. Acute kidney injury is the most frequent and most important organ failure, in particular in patients with chronic kidney disease. To date, there are no approved drug treatments that could effectively prevent acute kidney injury. SP16, an agonist of the low-density lipoprotein receptor-related protein 1, has been shown to exert both kidney- and cardioprotective effects in preclinical trials. Early clinical use of SP16 in phase I trials was safe. Administration of SP16 had beneficial trends on inflammatory response and infarct size in patients with ST-segment elevation myocardial infarction. The primary objective of this phase IIa trial is to demonstrate that injection of SP16 is safe and superior to placebo in preventing cardiac surgery-associated acute kidney injury within 7 days after surgery. Methods: This randomised, double-blinded, placebo-controlled, single-centre study evaluates the efficacy and safety of SP16 in 120 high-risk chronic kidney disease patients with disease stage G2-G3b undergoing cardiac surgery who are randomised into one of two treatment groups in a 1:1 ratio: SP16 (12 mg) or placebo. The study medication is administered via two subcutaneous injections, with the first dose given before surgery, followed by an additional dose after 9 h. Primary endpoints are the incidence of acute kidney injury during 7 days post-surgery and the frequency of adverse events within 72 h after index surgery. Important secondary endpoints include the incidence of major adverse kidney events at day 90 and impact on cardiac function. Safety assessments encompass adverse events, vital signs, electrocardiograms and routine safety laboratory tests. Additional evaluations include pharmacokinetics and immunological biomarkers. Discussion: This single-centre phase IIa trial will assess the incidence of cardiac surgery-associated acute kidney injury, describing the kidney-protective potential of SP16 and its safety profile in patients undergoing cardiac surgery. Trial registration: EUCT, EUCT number 2025-522491-89-00. Registered on February 2, 2026, https://euclinicaltrials.eu/ctis-public/view/2025-522491-89-00 . Patient recruitment is planned to start on August 1, 2026.