Factor H and factor H like-protein 1 (FHL-1) are complement regulatory proteins that serve as cofactors for the factor I-mediated cleavage of C3b. Some Lyme disease and relapsing fever spirochete species bind factor H to their surface to facilitate immune evasion. The Lyme disease spirochetes produce several factor H binding proteins (FHBPs) that form two distinct classes. Class I FHBPs (OspE orthologs and paralogs) bind only factor H, while class II FHBPs (BBA68) bind both factor H and FHL-1. BBA68 belongs to a large paralogous protein family, and of these paralogs, BBA69 is the member most closely related to BBA68. To determine if BBA69 can also bind factor H, recombinant protein was generated and tested for factor H binding. BBA69 did not exhibit factor H binding ability, suggesting that among family 54 paralogs, factor H binding is unique to BBA68. To identify the determinants of BBA68 that are involved in factor H binding, truncation and sitedirected mutational analyses were performed. These analyses revealed that the factor H binding site is discontinuous and provide strong evidence that coiled-coil structural elements are involved in the formation of the binding site.

Background Aripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU 960) is a new long-acting injectable antipsychotic formulation for gluteal administration every 2 months, currently being investigated for the treatment of schizophrenia and bipolar I disorder (BP-I). The objectives of this trial were to evaluate the safety and tolerability of Ari 2MRTU 960, and the similarity of aripiprazole plasma concentrations following administration of Ari 2MRTU 960 or aripiprazole once-monthly 400 mg (AOM 400), in adults with schizophrenia or BP-I. Methods This was a 32-week open-label study. Eligible participants were randomized 1:1 to receive Ari 2MRTU 960 every 56 ± 2 days (four injections scheduled) or AOM 400 every 28 ± 2 days (eight injections scheduled). Participants received overlapping oral antipsychotic treatment with the first administration of study drug (there was no oral overlap for participants stabilized on AOM 400). Safety, tolerability, and pharmacokinetics (PK) were evaluated throughout the study. Primary safety endpoints included reported adverse events, injection site reactions, and extrapyramidal symptoms. Primary PK endpoints were plasma concentration of aripiprazole 56 days after the fourth dose of Ari 2MRTU 960 and 28 days after the eighth dose of AOM 400, and area under the concentration–time curve (AUC) from Day 0 to 56 postdose after the fourth dose of Ari 2MRTU 960, or AUC from Day 0 to 28 after the seventh and eighth doses of AOM 400. Results Of the 266 participants enrolled (schizophrenia, n = 185; BP-I, n = 81), 132 were randomized to receive Ari 2MRTU 960 and 134 were randomized to receive AOM 400. The majority (66.2%) of participants were male; 72.9% were Black or African American, and mean age was 47.3 years; demographic characteristics and baseline disease characteristics were generally well balanced between groups. Study completion rate was 77.3% in the Ari 2MRTU 960 group and 68.7% in the AOM 400 group. The incidence of treatment-emergent adverse events (TEAEs) was similar between Ari 2MRTU 960 (71.2%) and AOM 400 (70.9%). The most frequently reported TEAEs were increased weight (Ari 2MRTU 960: 22.7%; AOM 400: 20.9%) and injection-site pain (Ari 2MRTU 960: 18.2%; AOM 400: 9.0%). The geometric means ratio (GMR) of aripiprazole plasma concentrations on the last day following the final dosing for Ari 2MRTU 960 versus AOM 400 was 1.011 (90% confidence interval [CI] 0.893–1.145), and the GMR of aripiprazole plasma exposure (area under the concentration–time curve) over the fourth Ari 2MRTU 960 dosing interval versus the seventh and eighth AOM 400 dosing intervals was 1.006 (90% CI 0.851–1.190). Conclusions Ari 2MRTU 960 was generally well tolerated in adults with schizophrenia or BP-I, with a safety profile comparable with that of AOM 400, and aripiprazole exposure equivalent to that with AOM 400 (ClinicalTrials.gov identifier: NCT04030143...

Background: The single-injection start regimen for aripiprazole once-monthly 400 mg (AOM 400) in patients with schizophrenia requires a single intramuscular injection in the gluteal or deltoid site and 14 days of concurrent oral therapy. A simplified, single-day regimen of two injections at separate gluteal and/or deltoid injection sites, together with a single 20-mg dose of oral aripiprazole on the 1st day, was assessed. Patients and methods: A previously developed population-pharmacokinetic (popPK) model for characterizing aripiprazole PK following oral administration and gluteal intramuscular depot injection was expanded to include deltoid injection. Simulations were conducted to assess PK profiles following various (including two-injection) start regimens. Postmarketing data on patients who received higherthan-recommended AOM doses were used to assess overall safety/tolerability. Results: The two-injection start regimen with a single concurrent oral dose displayed a comparable PK profile to the single-injection start regimen with concurrent 14-day oral administration in simulations. The safety assessment indicated the two-injection start regimen was unlikely to be associated with safety concerns beyond those expected with a single-injection start regimen. Conclusion: These data support use of the two-injection start regimen in clinical practice to reduce reliance on daily oral administration and optimize the therapeutic benefits of AOM 400 in patients with schizophrenia.

IntroductionAripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU 960) is a new long-acting injectable (LAI) antipsychotic formulation for gluteal administration every 2 months, intended for the treatment of schizophrenia and maintenance monotherapy treatment of bipolar I disorder (BP-I). This 32-week trial evaluated the safety, tolerability, and pharmacokinetic profile of multiple-dose administration of Ari 2MRTU 960 in clinically stable adult patients with a diagnosis of schizophrenia or BP-I, versus that of aripiprazole once-monthly 400 mg (AOM 400; an LAI indicated for the treatment of schizophrenia and maintenance monotherapy treatment of BP-I).MethodsThis was an open-label, multiple-dose, randomized, parallel-arm trial conducted at 16 sites in the US. Patients were randomized to receive Ari 2MRTU 960 every 56±2 days (n=132) or AOM 400 every 28±2 days (n=134). The primary objective was to establish the similarity of aripiprazole concentrations on the last day of the dosing interval, as well as exposure during the dosing interval (area under the concentration-time curve [AUC]), between Ari 2MRTU 960 and AOM 400 following multiple doses. It was pre-specified that the lower bound of the 90% confidence interval (CI) of the geometric means ratio (GMR) for these parameters must be >0.8.ResultsIn the Ari 2MRTU 960 group, 102 patients (77.3%) completed the study; in the AOM 400 group, 92 patients (68.7%) completed the study. The GMR of C56 for Ari 2MRTU 960 to C28 for AOM 400 was 1.011 (90% CI: 0.893, 1.145). The GMR (90% CI) of AUC0–56 for Ari 2MRTU 960 to AUC0–28 for AOM 400 was 1.006 (90% CI: 0.851, 1.190). Mean (standard deviation) maximum aripiprazole plasma concentration was 342 (157) ng/ml after the fourth Ari 2MRTU 960 dose and 344 (212) ng/ml after the eighth AOM 400 dose.ConclusionPharmacokinetic parameters were similar between Ari 2MRTU 960 and AOM 400.FundingOtsuka Pharmaceutical Development & Commercialization, Inc. (Princeton, NJ, USA) and H. Lundbeck A/S (Valby, Denmark).

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