Ladarixin, an inhibitor of the interleukin-8 receptors CXCR1 and CXCR2, in new-onset type 1 diabetes: A multicentre, randomized, double-blind, placebo-controlled trial.

AIM: To evaluate the ability of ladarixin (LDX, 400 mg twice-daily for three cycles of 14 days on/14 days off), an inhibitor of the CXCR1/2 chemokine receptors, to maintain C-peptide production in adult patients with newly diagnosed type 1 diabetes. MATERIALS AND METHODS: A double-blind, randomized (2:1), placebo-controlled study was conducted in 45 males and 31 females (aged 18-46 years) within 100 days of the first insulin administration. The primary endpoint was the area under the curve (AUC) for C-peptide in response to a 2-hour mixed meal tolerance test (AUC[0-120 min] ) at week 13 ± 1. Secondary endpoints included C-peptide AUC(15-120 min) , HbA1c, daily insulin requirement, severe hypoglycaemic events (SHE), the proportion of subjects achieving HbA1c less than 7.0% without SHE and maintaining a residual beta cell function. Follow-up assessments were scheduled at weeks 13 ± 1, 26 ± 2 and 52 ± 2. RESULTS: In total, 26/26 (100%, placebo) and 49/50 (98%, LDX) patients completed week 13. The mean change from baseline to week 13 in C-peptide AUC(0-120 min) was -0.144 ± 0.449 nmol/L with placebo and 0.003 ± .322 nmol/L with LDX. The difference was not significant (0.149 nmol/L, 95% CI -0.04 to 0.33; P = .122). At week 26, the proportion of patients with HbA1c less than 7.0% without SHE was transiently higher in the LDX group (81% vs. 54%, P = .024). Otherwise, no significant secondary endpoint differences were noted. Transient metabolic benefit was seen at week 26 in favour of the LDX group in the prespecified subpopulation with fasting C-peptide less than the median value at screening. CONCLUSIONS: In newly diagnosed patients with type 1 diabetes, short-term LDX treatment had no appreciable effect on preserving residual beta cell function.

Targeting CXCR1/2 in the first multicenter, double-blinded, randomized trial in autologous islet transplant recipients.

Several cytokines and chemokines are elevated after islet infusion in patients undergoing total pancreatectomy with islet autotransplantation (TPIAT), including CXCL8 (also known as interleukin-8), leading to islet loss. We investigated whether use of reparixin for blockade of the CXCL8 pathway would improve islet engraftment and insulin independence after TPIAT. Adults without diabetes scheduled for TPIAT at nine academic centers were randomized to a continuous infusion of reparixin or placebo (double-blinded) for 7 days in the peri-transplant period. Efficacy measures included insulin independence (primary), insulin dose, hemoglobin A1c (HbA1c ), and mixed meal tolerance testing. The intent-to-treat population included 102 participants (age 39.5 ± 12.2 years, 69% female), n = 50 reparixin-treated, n = 52 placebo-treated. The proportion insulin-independent at Day 365 was similar in reparixin and placebo: 20% vs. 21% (p = .542). Twenty-seven of 42 (64.3%) in the reparixin group and 28/45 (62.2%) in the placebo group maintained HbA1c ≤6.5% (p = .842, Day 365). Area under the curve C-peptide from mixed meal testing was similar between groups, as were adverse events. In conclusion, reparixin infusion did not improve diabetes outcomes. CXCL8 inhibition alone may be insufficient to prevent islet damage from innate inflammation in islet autotransplantation. This first multicenter clinical trial in TPIAT highlights the potential for future multicenter collaborations.

Targeting CXCR1/2 Does Not Improve Insulin Secretion After Pancreatic Islet Transplantation: A Phase 3, Double-Blind, Randomized, Placebo-Controlled Trial in Type 1 Diabetes.

OBJECTIVE: Reparixin is an inhibitor of CXCR1/2 chemokine receptor shown to be an effective anti-inflammatory adjuvant in a pilot clinical trial in allotransplant recipients. RESEARCH DESIGN AND METHODS: A phase 3, multicenter, randomized, double-blind, parallel-assignment study (NCT01817959) was conducted in recipients of islet allotransplants randomized (2:1) to reparixin or placebo in addition to immunosuppression. Primary outcome was the area under the curve (AUC) for C-peptide during the mixed-meal tolerance test at day 75 ± 5 after the first and day 365 ± 14 after the last transplant. Secondary end points included insulin independence and standard measures of glycemic control. RESULTS: The intention-to-treat analysis did not show a significant difference in C-peptide AUC at both day 75 (27 on reparixin vs. 18 on placebo, P = 0.99) and day 365 (24 on reparixin vs. 15 on placebo, P = 0.71). There was no statistically significant difference between treatment groups at any time point for any secondary variable. Analysis of patient subsets showed a trend for a higher percentage of subjects retaining insulin independence for 1 year after a single islet infusion in patients receiving reparixin as compared with patients receiving placebo (26.7% vs. 0%, P = 0.09) when antithymocyte globulin was used as induction immunosuppression. CONCLUSIONS: In this first double-blind randomized trial, islet transplantation data obtained with reparixin do not support a role of CXCR1/2 inhibition in preventing islet inflammation-mediated damage.

CXCR1/2 inhibition blocks and reverses type 1 diabetes in mice.

Chemokines and their receptors have been associated with or implicated in the pathogenesis of type 1 diabetes (T1D), but the identification of a single specific chemokine/receptor pathway that may constitute a suitable target for the development of therapeutic interventions is still lacking. Here, we used multiple low-dose (MLD) streptozotocin (STZ) injections and the NOD mouse model to investigate the potency of CXCR1/2 inhibition to prevent inflammation- and autoimmunity-mediated damage of pancreatic islets. Reparixin and ladarixin, noncompetitive allosteric inhibitors, were used to pharmacologically blockade CXCR1/2. Transient blockade of said receptors was effective in preventing inflammation-mediated damage in MLD-STZ and in preventing and reversing diabetes in NOD mice. Blockade of CXCR1/2 was associated with inhibition of insulitis and modification of leukocytes distribution in blood, spleen, bone marrow, and lymph nodes. Among leukocytes, CXCR2(+) myeloid cells were the most decreased subpopulations. Together these results identify CXCR1/2 chemokine receptors as "master regulators" of diabetes pathogenesis. The demonstration that this strategy may be successful in preserving residual ß-cells holds the potential to make a significant change in the approach to management of human T1D.

CXCR1/2 inhibition enhances pancreatic islet survival after transplantation.

Although long considered a promising treatment option for type 1 diabetes, pancreatic islet cell transformation has been hindered by immune system rejection of engrafted tissue. The identification of pathways that regulate post-transplant detrimental inflammatory events would improve management and outcome of transplanted patients. Here, we found that CXCR1/2 chemokine receptors and their ligands are crucial negative determinants for islet survival after transplantation. Pancreatic islets released abundant CXCR1/2 ligands (CXCL1 and CXCL8). Accordingly, intrahepatic CXCL1 and circulating CXCL1 and CXCL8 were strongly induced shortly after islet infusion. Genetic and pharmacological blockade of the CXCL1-CXCR1/2 axis in mice improved intrahepatic islet engraftment and reduced intrahepatic recruitment of polymorphonuclear leukocytes and NKT cells after islet infusion. In humans, the CXCR1/2 allosteric inhibitor reparixin improved outcome in a phase 2 randomized, open-label pilot study with a single infusion of allogeneic islets. These findings indicate that the CXCR1/2-mediated pathway is a regulator of islet damage and should be a target for intervention to improve the efficacy of transplantation.