Safety and tolerability of a humanized rabbit monoclonal antibody (SSS07) in healthy adults: Randomized double-blind placebo-controlled single ascending dose trial.

SSS07, a humanized rabbit monoclonal antibody, can selectively block human tumor necrosis factor-α (TNF-α). The objective of this study was to assess the safety, tolerability, and relative immunogenicity of SSS07 after multiple single subcutaneous (SC) doses in healthy volunteers. A total of 71 healthy volunteers were randomized to six sequential ascending-dose groups (5, 15, 30, 50, 75, and 100 mg), and except for the 100 mg group that only had one subject who received a placebo, all of the other groups included two placebo-control subjects. Safety, tolerability, and immunogenicity were assessed by physical examinations, vital signs, electrocardiography (ECG), clinical laboratory tests, and plasma anti-drug antibody (ADA) over 28 days for each group. Their concentrations of TNF-α were also analyzed. Only after safety and tolerance were determined in the lower-dose groups was the next dose group initiated. The dose increments did not exceed 100 mg. No serious adverse events or dose-limited toxicity (DLT) were observed, so 100 mg was defined as the maximum tolerated dose (MTD). Overall, 71 AEs and 59 treatment-related adverse events (TRAEs) were reported in 36 (60.0%) and 30 (50.0%) volunteers, respectively, who received SSS07. All AEs and TRAEs were mild or moderate and expected based on previous results with similar types of drugs, without new safety concerns. Except for infections and administration site reactions, the frequency and intensity of the other TRAEs were similar for SSS07 and placebo. No severe acute immune reactions occurred. The lower dose's immunogenicity was stronger than the higher doses. The highest ADA titer was observed 3 to 6 months after administration. SSS07 was generally safe and well tolerated in healthy Chinese volunteers. Higher immunogenicity was observed at low SSS07 concentration levels. The infections and administration site conditions might have been related to the immunogenicity and the degree of inhibition of TNF-α. However, the existence of ADA did not appear to affect the safety of the subjects throughout the follow-up period. These findings could support further investigations of treatments with humanized monoclonal antibodies.

Liu C ，Dong W ，Xia L ，Lv J ，Jiang D ，Wang Q ，Wang M ，Wu M ，Miao J ，Tao T ，Wang D ，Zheng L ，Su S ，Liu L ，Fang Y ... -  《-》

A randomized controlled dose-escalation study of SSS07, a humanized rabbit anti-human TNF alpha antibody, in healthy Chinese adults.

SSS07 is a rabbit derived humanized anti-human TNF-α antibody. This study aimed to explore the pharmacokinetics, safety, and immunogenicity of SSS07 when administrated subcutaneously in healthy adults. This was a double-blind, dose-escalation study of SSS07 in 71 adults. Dose cohorts were set to 5 mg, 15 mg, 30 mg, 50 mg, 75 mg, and 100 mg. In each dosage group, other than 100 mg, twelve healthy participants were randomly assigned to receive a single dose of SSS07 (n = 10) or placebo (n = 2). Blood samples were taken for pharmacokinetics and immunogenicity analysis. No deaths, serious adverse events or drug-related withdrawals occurred in this trial. No drug limited toxicity appeared. After subcutaneous injection, SSS07 was absorbed slowly with Tmax ranging from 60 to 264 h but eliminated quickly with a short half-life ranging from 21.69 to 78.4 h (1-3 days). From 5 mg to 100 mg, dose-exposure proportionality analysis found a 90% confidence interval (CI) of β of Cmax (1.015-1.193), AUC0-t (1.096-1.263) and AUC0-∞ (0.999-1.174) partially within the range 0.926-1.074. The plasma concentration of TNF-α decreased significantly post-dose, but a few days later, levels of TNF-α elevated rapidly and exceeded its baseline value. All participants receiving SSS07 were found to be anti-drug antibody positive during the study. A single-dose injection of SSS07 was safe and well-tolerated in healthy adults. Doses of SSS07 from 5 mg to 100 mg could not be regarded as nonlinear, based on dose-exposure proportionality analysis. A high incidence of anti-drug antibodies indicated strong immunogenicity, which may influence the pharmacokinetics profile and interfere with the TNF-α inhibition capability of SSS07.

Wang Q ，Xie X ，Su F ，Wang J ，Chen S ，Wang Q ，Jiang D ，Wang Y ，Zhang T ，Liu C ，Han M ，Tao T ，Wu Q ，Xi N ，Li Z ，Song H ，Fang Y ... -  《-》

A Phase 1 Single-Ascending-Dose Trial in Healthy Volunteers to Evaluate the Safety, Tolerability, Pharmacokinetics, and Immunogenicity of Intravenous PNT001, a Novel Mid-domain Tau Antibody Targeting cis-pT231 Tau.

Luca W ，Foster K ，McClure K ，Ahlijanian MK ，Jefson M ... -  《-》

Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of Stapokibart in Healthy Volunteers and Adult Subjects with Atopic Dermatitis.

Stapokibart, a novel humanized anti-interleukin (IL)-4 receptor alpha monoclonal antibody, inhibits the signaling of IL-4 and IL-13, which are key drivers of type 2 inflammation in atopic dermatitis (AD). This study aimed to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of stapokibart in a randomized, double-blind, placebo-controlled single ascending dose (SAD) study and a multiple ascending dose (MAD) study. The SAD study enrolled 33 healthy male adults aged 18-65 years at a single center. The MAD study enrolled 39 patients with moderate-to-severe AD aged 18-70 years at seven centers. Enrolled subjects were randomized to subcutaneous (SC) doses of stapokibart (75-600 mg) or placebo. Serum thymus and activation-regulated chemokine (TARC) and total immunoglobulin E (IgE) were measured as PD biomarkers for stapokibart. Similar PK characteristics were observed in healthy volunteers and subjects with AD after the initial administration. Stapokibart exhibited non-linear pharmacokinetics in both types of subjects. Following single doses, the mean maximum serum concentration (Cmax) ranged from 5.3 to 63.0 μg/mL, median Tmax ranged from 3.0 to 7.0 days, mean terminal half-life (t1/2z) ranged from 2.39 to 7.43 days, and mean apparent volume (Vz/F) ranged from 3.64 to 6.73 L in healthy subjects. The mean AUC accumulation ratio was 2.29 in subjects with AD after three doses of stapokibart 300 mg administered every 2 weeks. The median serum total IgE and TARC levels on day 43 decreased from baseline by 14.9-25.2% and 48.6-77.0%, respectively, among subjects with AD receiving three doses of stapokibart. No subjects developed grade ≥ 3 adverse events (AEs) or serious AEs or discontinued the study because of AEs. The incidence of AEs was similar between stapokibart and placebo groups. Stapokibart showed favorable pharmacokinetics, pharmacodynamics, safety, and tolerability in the SAD and MAD studies. Based on these results, phase II and phase III trials of stapokibart have been performed in subjects with moderate-to-severe AD. ClinicalTrials.gov Identifier NCT06161090 (29 November, 2023), NCT04893941 (15 May, 2021).

Zhang L ，Zhang W ，Xu Y ，Dong L ，Sun Y ，Jia Y ，Li Z ，Chen B ，Hou J ，Zhang J ... -  《-》

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose Study to Evaluate the Pharmacokinetics, Immunogenicity, Safety, and Tolerability After Subcutaneous Administration of Tozorakimab in Healthy Chinese Participants.

Tozorakimab is a high-affinity human immunoglobulin G1 monoclonal antibody that neutralizes interleukin (IL)-33, an IL-1 family cytokine. This phase 1, single-center, randomized, double-blind, placebo-controlled, single ascending dose study (NCT05070312) evaluated tozorakimab in a healthy Chinese population. Outcomes included the characterization of the pharmacokinetic (PK) profile and immunogenicity of tozorakimab. Safety outcomes included treatment-emergent adverse events (TEAEs) and clinical laboratory, electrocardiogram, and vital sign parameters. Healthy, non-smoking, male, and female Chinese participants aged 18-45 years with a body mass index 19-24 kg/m2 were enrolled. In total, 36 participants across 2 cohorts of 18 participants were randomized 2:1 to receive a single subcutaneous dose of tozorakimab (300 mg [2 mL] or 600 mg [4 mL]) or matching placebo (2 or 4 mL). Tozorakimab showed dose-dependent serum PK concentrations with an approximate monophasic distribution in serum over time and a maximum observed peak concentration of 20.1 and 33.7 μg/mL in the 300- and 600-mg cohorts, respectively. No treatment-emergent anti-drug antibodies for tozorakimab were observed in any of the participants. There were no clinically relevant trends in the occurrence of TEAEs across the treatment groups. There were no clinically relevant trends over time in clinical laboratory (hematology, clinical chemistry, and urinalysis), electrocardiogram, or vital sign parameters in any treatment group. Overall, tozorakimab demonstrated dose-dependent systemic exposure in healthy Chinese participants and was well tolerated, with no safety concerns identified in this study.

Li Y ，Zhang H ，Pandya H ，Miao L ，Reid F ，Jimenez E ，Sadiq MW ，Moate R ，Lei A ，Zhou XH ，Kell C ，Ding J ，Zhang G ，Zhao L ，Ge X ... -  《Clinical Pharmacology in Drug Development》