Post-Marketing Surveillance of the World's First Novel Cocktail of Rabies Monoclonal Antibodies: TwinRab™ in Real \-World Setting

Abstract

Rabies presents with a high fatality rate, which imposes a significant global public health challenge, and therefore the use of post-exposure prophylaxis (PEP) is crucial for prevention. Monoclonal antibodies (mAbs) have emerged as a promising substitute for rabies immunoglobulins (RIGs) due to their high efficacy and standardized manufacturing process. A prospective, open-label, post-marketing surveillance study (PMS) was conducted at Byramjee Jeejeebhoy Medical College (BJMC), Pune. The study included patients aged more than 2 years who had recently sustained Category III-suspected rabid animal bite exposures. These patients were administered TwinRabTM at a dosage of 40 IU/kg in and around the wound as intralesional transfer, along with the anti-rabies vaccine (ARV). Adverse events (AEs) grading was performed with reference to the Food and Drug Administration (FDA) toxicity grading. In this study, 215 subjects received the TwinRabTM mAb with a 100% completion rate. Out of 215 patients, three (1.3%) patients in the range of 18 to 65 years of age showed solicited local AEs, which were resolved after the appropriate treatment intervention, but causality assessment was non-assessable. The overall tolerability assessment showed positive ratings from doctors (91.63%) and patients (67.91%) for the mAb cocktail. The PMS demonstrated the safety of TwinRabTM in patients who experienced Category III-suspected rabid animal bites, thereby supporting its potential as an alternative option for post-exposure prophylaxis in the management of animal bites for the prevention of rabies.

Keywords: Adverse events; TwinRab™; post-exposure prophylaxis; post-marketing surveillance; rabies; safety assessment.

Figure 1

The cocktail of two monoclonal antibodies was administered along with ARV intradermally on days 0, 3, 7, and 28, according to the updated Thai Red Cross Regimen, and intramuscularly on days 0, 3, 7, 14, and 28 according to the Essen Pep Regimen (14^th day only for the IM schedule). ARV: anti-rabies vaccine; PEP: post-exposure prophylaxis

Figure 2

Overall tolerability assessment