A Randomized Pharmacokinetic Study in Healthy Male Subjects Comparing a High-concentration, Citrate-free SB5 Formulation (40 mg/0.4 ml) and Prior SB5 (Adalimumab Biosimilar).

INTRODUCTION: SB5 is an approved biosimilar of adalimumab, a monoclonal anti-tumor necrosis factor (anti-TNF) antibody. This study compared pharmacokinetics (PK), safety, tolerability, and immunogenicity between a new high-concentration, low-volume, and citrate-free formulation (40 mg/0.4 ml, SB5-HC) and the current low-concentration formulation with higher volume (40 mg/0.8 ml, SB5-LC) to evaluate the bioequivalence of the two formulations. METHODS: This study was a randomized, single-blind, two-arm, parallel-group, single-dose study in healthy male subjects. Subjects were randomized to receive either SB5-HC or SB5-LC via subcutaneous injection using a pre-filled syringe. Primary endpoints were the area under the curve of the concentration-time curve from zero to infinity (AUCinf) and maximum serum concentration (Cmax). Bioequivalence was achieved if the 90% confidence intervals (CIs) for the ratios of the geometric least squares mean (LSMean) of primary endpoints were within the pre-defined bioequivalence margins of 0.80-1.25. Secondary endpoints included safety, tolerability, and immunogenicity. RESULTS: Subjects (n = 188) were randomized to SB5-HC (n = 94) or SB5-LC (n = 94). Baseline characteristics were comparable between the two treatment groups. The mean values for AUCinf and Cmax were similar between the SB5-HC and SB5-LC groups. For the primary endpoints, the geometric LSMean ratios (90% CI) for AUCinf and Cmax were 0.920 (0.8262-1.0239) and 0.984 (0.9126-1.0604), respectively, placing the corresponding 90% CIs well within the pre-defined bioequivalence margin of 0.80-1.25. All treatment-emergent adverse events (TEAEs) were considered mild to moderate and were reported for 44.7% and 51.1% of subjects in the SB5-HC and SB5-LC groups, respectively. Immunogenicity assessed by frequency of occurrence of anti-drug antibodies (ADAs) and neutralizing antibodies (NAbs) was comparable between groups. CONCLUSIONS: This bridging study demonstrated PK equivalence and comparable safety and tolerability of subcutaneous injection of SB5 via SB5-HC or SB5-LC. CLINICALTRIALS: GOV IDENTIFIER: https://clinicaltrials.gov/ct2/show/NCT04514796 .

Protein grafting of p53TAD onto a leucine zipper scaffold generates a potent HDM dual inhibitor.

Reactivation of the p53 pathway by a potential therapeutic antagonist, which inhibits HDM2 and HDMX, is an attractive strategy for drug development in oncology. Developing blockers towards conserved hydrophobic pockets of both HDMs has mainly focused on small synthetic compounds; however, this approach has proved challenging. Here we describe an approach to generate a potent HDM dual inhibitor, p53LZ2, by rational protein grafting of the p53 transactivation domain onto a homodimeric leucine zipper. p53LZ2 shows tight binding affinity to both HDMs compared with wild-type p53 in vitro. X-ray crystallographic, comparative modelling and small-angle X-ray scattering studies of p53LZ2-HDM complexes show butterfly-shaped structures. A cell-permeable TAT-p53LZ2 effectively inhibits the cancer cell growth in wild-type but not mutant p53 by arresting cell cycle and inducing apoptosis in vitro. Thus, p53LZ2, designed by rational grafting, shows a potential therapeutic approach against cancer.

Mucosal prior to systemic application of recombinant adenovirus boosting is more immunogenic than systemic application twice but confers similar protection against SIV-challenge in DNA vaccine-primed macaques.

We investigated the immunogenicity and efficacy of a bimodal prime/boost vaccine regimen given by various routes in the Simian immunodeficiency virus (SIV) rhesus monkey model for AIDS. Twelve animals were immunized with SIV DNA-vectors followed by the application of a recombinant adenovirus (rAd5) expressing the same genes either intramuscularly (i.m.) or by oropharyngeal spray. The second rAd5-application was given i.m. All vaccinees plus six controls were challenged orally with SIVmac239 12 weeks post-final immunization. Both immunization strategies induced strong SIV Gag-specific IFN-gamma and T-cell proliferation responses and mediated a conservation of CD4(+) memory T-cells and a reduction of viral load during peak viremia following infection. Interestingly, the mucosal group was superior to the systemic group regarding breadth and strength of SIV-specific T-cell responses and exhibited lower vector specific immune responses. Therefore, our data warrant the inclusion of mucosal vector application in a vaccination regimen which makes it less invasive and easier to apply.

Immunogenicity of a DNA prime and recombinant adenovirus boost regime significantly varies between rhesus macaques of Chinese and Indian origins.

BACKGROUND: Due to an ever increasing shortage of rhesus macaques of Indian origin (InR) that have been generally used for preclinical AIDS vaccine trials in non-human primates, demand is rising for Chinese rhesus macaques (ChR). However, the immunogenicity of an AIDS vaccine candidate has not been compared in parallel in both rhesus macaque subspecies. METHODS: ChR and InR were immunized with SIV/HIV DNA and adenovirus vaccine and their immune responses to SIV and HIV evaluated. RESULTS: SIV Gag- and Env-specific T-cell responses and SIV-specific lymphoproliferative responses measured in ChR were significantly weaker than those in InR (P < 0.05). By contrast, antibody responses to SIV Env, Tat, and Nef in ChR were stronger than those in InR (P < 0.05). CONCLUSIONS: Immunogenicity of an AIDS vaccine can vary significantly depending on the geographic origin implying genetic differences of macaques. This must be considered when describing and interpreting results of such vaccine studies.