1. A phase 2b, Randomized, double blinded comparison of the safety and efficacy of the monoclonal antibody mixture SYN023 and human rabies immune globulin in patients exposed to rabies.
- Author
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Quiambao BP, Payumo RA, Roa C, Borja-Tabora CF, Emmeline Montellano M, Reyes MRL, Zoleta-De Jesus L, Capeding MR, Solimen DP, Barez MY, Reid C, Chuang A, Tsao E, and McClain JB
- Subjects
- Humans, Male, Female, Adult, Middle Aged, Double-Blind Method, Young Adult, Adolescent, Aged, Child, Rabies prevention & control, Rabies immunology, Antibodies, Viral immunology, Post-Exposure Prophylaxis methods, Antibodies, Monoclonal immunology, Antibodies, Monoclonal therapeutic use, Antibodies, Monoclonal adverse effects, Antibodies, Monoclonal administration & dosage, Antibodies, Neutralizing immunology, Antibodies, Neutralizing blood, Rabies virus immunology, Rabies Vaccines immunology, Rabies Vaccines adverse effects, Rabies Vaccines administration & dosage, Rabies Vaccines therapeutic use
- Abstract
Background: SYN023 is an anti-rabies monoclonal antibody mixture administered as part of post-exposure prophylaxis regimens. The rabies virus neutralizing antibody (RVNA) concentration generally accepted as an adequate immune response to vaccination is ≥ 0.5 IU/mL., Methods: Within 54 h of potential rabies exposure, 448 patients in two risk substrata of WHO Category III exposure were randomized to receive either 0.3 mg/kg SYN023 or 0.133 mL/kg human rabies immunoglobulin (HRIG) injected in and around the wound site(s) plus a course of rabies vaccination. Patients were followed for safety and absence of rabies for ≥ 365 days., Results: GMT RVNA was higher with SYN023 throughout the 2-week post-treatment period. In the primary analysis group (n = 368), 99.4 % of SYN023 recipients versus 4.5 % of HRIG recipients had protective RVNA levels on Day 4. On Day 8, 98.1 % SYN023 versus 12.2 % HRIG recipients were protected. The SYN023:HRIG ratio of geometric mean titer of RVNA (RVNA GMTs) on Day 8 (19.42) exceeded the 10 % superiority margin (P < 0.0001) indicating higher Day 8 RVNA with SYN023. On Day 99, the SYN023:HRIG RVNA GMT ratio (0.66) was below the non-inferiority margin of 20 % (P = 0.9485) suggesting some moderation of vaccine immune response by SYN023 relative to HRIG. The ratio of percent SYN023:HRIG recipients achieving RVNA ≥ 0.5 IU/mL on Day 99 (0.98) met the non-inferiority margin of 20 % (P = 0.013) indicating anti-rabies immune response with SYN023 was non-inferior to HRIG despite this effect. There were no probable/confirmed rabies cases in any patient. Study regimens were well tolerated., Conclusions: SYN023 provided higher RVNA than HRIG soon after rabies exposure. By Day 99 post-treatment, GM RVNA with SYN023 was lower than HRIG, however, the percent of SYN023 recipients with a protective response was not inferior at this time point. No rabies cases were reported in the study. The SYN023 safety profile was acceptable., Clinicaltrials: gov ID: NCT03961555., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [A.C. and E.T. are employed by Synermore Biologics (Suzhou) Co. C.R. and J.B.M. are paid consultants to Synermore Biologics (Suzhou) Co.]., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
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