Search Results (11)

Botulinum neurotoxin type A (BoNT/A) is intramuscularly injected for the treatment of, e.g., spasticity, cervical dystonia or facial lines. Several BoNT/A products with or without complexing proteins, with non-interchangeable dose units and various duration of effect claims, are approved but hard to compare. The goal of this study was to compare the complexing protein-free approved BoNT/A products IncobotulinumtoxinA (INCO), DaxibotulinumtoxinA (DAXI) and RelabotulinumtoxinA (RELA) in vitro and in vivo. BoNT/A protein content per 100 U was lowest in INCO and highest in DAXI (INCO 0.44, RELA 0.46, DAXI 0.58 ng/100 U). Relative bioactivity of INCO, DAXI and RELA was comparable (116, 104 and 117 U/100 labeled units). INCO and DAXI caused a maximum mouse digit abduction score (DAS) 2–3 days after IM injection of 20 or 40 U/kg. The DAS after 20 U/kg INCO was higher and showed a 10 days longer paralysis than DAXI at equivalent dosing. The in vivo spread of DAXI in the mouse gastrocnemius muscle was indistinguishable from that after INCO, and the spread of RELA ex vivo in porcine muscle was larger than INCO but equal to 0.9% NaCl. These results show the differences between 150 kDa botulinum type A toxin products beyond the published claims. Full article

DaxibotulinumtoxinA for injection (DAXI) is a botulinum neurotoxin (BoNT) drug product comprising the 150 kDa pure BoNT/A1 as the drug substance formulated with a proprietary stabilizing excipient, RTP004. We hypothesized that RTP004 facilitates localization of BoNT/A1 to the neuronal membrane, resulting in increased BoNT internalization and cleavage of the synaptosomal-associated protein of 25 kDa (SNAP-25) within synaptic terminals. We characterized the interaction between RTP004 and BoNT/A1 using in silico and in vitro techniques. In vitro analyses revealed that negative charges on the BoNT/A1 surface were located on the light chain (LC, the catalytic domain) and the C-terminus of the heavy chain (H_C, the receptor-binding domain), potentially providing sites for interaction with the positively charged RTP004 peptide. RTP004 bound to BoNT/A1, but not to human serum albumin (HSA), in both static and dynamic conditions. RTP004, not HSA, enhanced binding of BoNT to artificial membranes and RTP004 dissociated from BoNT under conditions that mimicked physiological conditions of the synaptic vesicle. RTP004 also increased binding of BoNT to the synaptosomal cell membrane and enhanced cleavage of SNAP-25 in a dose-dependent manner. These findings demonstrate that RTP004, not the excipient HSA common in other BoNT/A1 drug products, enhances binding of BoNT to the cell surface, facilitates internalization of BoNT into the cell, and increases SNAP-25 cleavage. Full article

The therapeutic efficacy remaining from prior treatments with botulinum toxins (BoNTs) when cervical dystonia (CD) patients prefer to be re-treated has not been well characterized. Here, we assessed the residual therapeutic efficacy of BoNT injections at the time of a patient-desired re-treatment. In pivotal trials for daxibotulinumtoxinA (DAXI) in CD, subjects could request re-treatment before returning to pre-treatment symptom levels (defined as ≤20% of peak efficacy remaining). In this post hoc analysis of the Phase 3 ASPEN-OLS trial, the median percent efficacy remaining (based on change in TWSTRS total score) was determined in subjects who requested re-injection before returning to pre-treatment symptoms. Dysphagia and muscle weakness were evaluated in patients requesting re-treatment with efficacy remaining, relative to those waiting to return to baseline. There were 264 (28.7% of 920 total treatments) patient requests for re-treatment before returning to pre-treatment status across the study. The median percent efficacy remaining at the time of requested re-injection was 45.5%, which corresponded to a median of 16.0 weeks (range 10.9–40.3) post-treatment. The rates of dysphagia (≤4.9%) and muscle weakness (≤6.8%) were low and were not significantly different in those who waited for return to pre-treatment symptom status versus subjects who requested re-injection with efficacy remaining. A significant proportion of CD patients wished to be re-treated with efficacy still remaining from prior BoNT injections as early symptoms re-emerged. With the overall clinical profile of DAXI, physicians can safely provide individualized treatment regimens based on the treatment goals or symptomatic needs of their patients. Full article

The first-line management of cervical dystonia (CD) symptoms is intramuscular injection of botulinum toxin type A (BoNTA). However, a comparison of safety among BoNTAs is difficult because, per regulatory authorities, units of BoNTA activity are not interchangeable. Dysphagia and muscle weakness are widely considered two key adverse events to monitor closely in the treatment of CD. This integrated analysis compared the safety of BoNTAs approved for CD in the US by evaluating relationships between the incidence of dysphagia and muscle weakness in prescribing information and the core neurotoxin content. Coefficients The coefficients of determination (R²) and trendlines were estimated via regression-based lines of best fit. Adverse drug reaction (ADR) rates were strongly correlated with core neurotoxin amounts for conventional BoNTAs (slope coefficients: dysphagia = 0.048, R² = 0.74; muscle weakness = 0.096, R² = 0.82). The published ADR rates at approved doses for conventional BoNTAs were higher compared with DaxibotulinumtoxinA (DAXI; DAXXIFY^®, Revance Therapeutics, Inc., Nashville, TN, USA) by core neurotoxin content. The use of a core neurotoxin amount was found to be an effective method for comparing the safety of BoNTA products. Current clinical trials suggest that DAXI, a novel BoNTA formulation, provides a potentially wider safety margin compared with other approved BoNTAs for CD. The lower amount of core neurotoxin administered at approved doses compared with conventional BoNTAs may explain low on-target ADRs like muscle weakness, whereas reduced diffusion from the injection site is thought to be responsible for low off-target ADRs like dysphagia. Full article

The formation of neutralizing antibodies is a growing concern in the use of botulinum neurotoxin A (BoNT/A) as it may result in secondary treatment failure. Differences in the immunogenicity of BoNT/A formulations have been attributed to the presence of pharmacologically unnecessary bacterial components. Reportedly, the rate of antibody-mediated secondary non-response is lowest in complexing protein-free (CF) IncobotulinumtoxinA (INCO). Here, the published data and literature on the composition and properties of the three commercially available CF-BoNT/A formulations, namely, INCO, Coretox^® (CORE), and DaxibotulinumtoxinA (DAXI), are reviewed to elucidate the implications for their potential immunogenicity. While all three BoNT/A formulations are free of complexing proteins and contain the core BoNT/A molecule as the active pharmaceutical ingredient, they differ in their production protocols and excipients, which may affect their immunogenicity. INCO contains only two immunologically inconspicuous excipients, namely, human serum albumin and sucrose, and has demonstrated low immunogenicity in daily practice and clinical studies for more than ten years. DAXI contains four excipients, namely, L-histidine, trehalosedihydrate, polysorbate 20, and the highly charged RTP004 peptide, of which the latter two may increase the immunogenicity of BoNT/A by introducing neo-epitopes. In early clinical studies with DAXI, antibodies against BoNT/A and RTP004 were found at low frequencies; however, the follow-up period was critically short, with a maximum of three injections. CORE contains four excipients: L-methionine, sucrose, NaCl, and polysorbate 20. Presently, no data are available on the immunogenicity of CORE in human beings. It remains to be seen whether all three CF BoNT/A formulations demonstrate the same low immunogenicity in patients over a long period of time. Full article

DaxibotulinumtoxinA-lanm for injection (DAXI) is a unique US Food and Drug Administration-approved product comprising daxibotulinumtoxinA and a stabilizing excipient peptide (RTP004). DAXI has a longer-labeled shelf life (72 h) following reconstitution than other botulinum toxin type A products. Here, we report the stability and microbial control of reconstituted DAXI when stored at 2 °C–8 °C over a period of 36 days (Study 1) and 7 days (Study 2) following reconstitution with unpreserved or preserved saline. The pH and biological activity of reconstituted DAXI in the 50 U/vial and 100 U/vial formats remained stable at the final assessed time point in both preserved and unpreserved saline when refrigerated (2 °C–8 °C). No changes in recoverable 150 kDa neurotoxin (measured by enzyme-linked immunosorbent assay) were observed over 6 days of refrigeration. Bacterial growth or pathogen proliferation was not observed in DAXI reconstituted in preserved or unpreserved saline in both studies. Full article

Botulinum toxin (BoNT) is an anaerobic rod-shaped-neurotoxin produced by Clostridium botulinum, that has both therapeutic and lethal applications. BoNT injection is the most popular cosmetic procedure worldwide with various applications. Patients with dynamic wrinkles in areas such as the glabella, forehead, peri-orbital lines, nasal rhytides, and perioral rhytides are indicated. Excessive contraction of muscles or hyperactivity of specific muscles such as bulky masseters, cobble stone chins, gummy smiles, asymmetric smiles, and depressed mouth corners can achieve esthetic results by targeting the precise muscles. Patients with hypertrophic submandibular glands and parotid glands can also benefit esthetically. There are several FDA-approved BoNTs (obabotuli-numtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, letibotulinumtoxinA, prabotulinumtox-inA, daxibotulinumtoxinA, rimbotulinumtoxinB) and novel BoNTs on the market. This paper is a narrative review of the consensus statements of expert practitioners and various literature on the injection points and techniques, highlighting both the Asian and Caucasian population separately. This paper can serve as a practical illustrative guide and reference for optimal, safe injection areas and effective doses for application of BoNT in the face and oral and maxillofacial area. The history of BoNT indications, contraindications, and complications, and the merits of ultrasonography (US)-assisted injections are also discussed. Full article

DaxibotulinumtoxinA for Injection (DAXI) is a novel botulinum toxin type A product containing daxibotulinumtoxinA with a stabilizing excipient peptide (RTP004). DAXI immunogenicity was assessed in three phase 3 glabellar line studies (two placebo-controlled, single-dose studies and an open-label repeat-dose safety study). Binding antibodies to daxibotulinumtoxinA and RTP004 were detected by validated ELISAs. Samples positive for daxibotulinumtoxinA-binding antibodies were evaluated further for titer and neutralizing antibodies by mouse protection assay. Overall, 2786 subjects received DAXI and 2823 subjects were exposed to RTP004 as DAXI (n = 2786) or placebo (n = 37). Treatment-related anti-daxibotulinumtoxinA binding antibodies were detected in 21 of 2737 evaluable subjects (0.8%). No subject developed neutralizing antibodies. Treatment-related anti-RTP004 binding antibodies were detected in 35 (1.3%) of 2772 evaluable subjects. Binding antibodies were generally transient, of low titer (<1:200), and no subject had binding antibodies to both daxibotulinumtoxinA and RTP004. All subjects with treatment-induced binding antibodies to daxibotulinumtoxinA or RTP004 achieved none or mild glabellar line severity at Week 4 following each DAXI cycle, indicating no impact on DAXI efficacy. No subjects with binding antibodies to daxibotulinumtoxinA or RTP004 reported immune-related adverse events. This evaluation of anti-drug antibody formation with DAXI shows low rates of antibody formation to both daxibotulinumtoxinA and RTP004. Full article

Blepharospasm and oromandibular dystonia are focal dystonias characterized by involuntary and often patterned, repetitive muscle contractions. There is a long history of medical and surgical therapies, with the current first-line therapy, botulinum neurotoxin (BoNT), becoming standard of care in 1989. This comprehensive review utilized MEDLINE and PubMed and provides an overview of the history of these focal dystonias, BoNT, and the use of toxin to treat them. We present the levels of clinical evidence for each toxin for both, focal dystonias and offer guidance for muscle and site selection as well as dosing. Full article