Assessment of Long-term Clinical Response to BoNT in Cervical Dystonia (RELY-CD)

Merz Pharmaceuticals

Status: Completed

Conditions: Cervical Dystonia

Treatments: Biological: CC BoNT/A; Biological: CF to CC BoNT/A; Biological: CF BoNT/A; Biological: CC to CF BoNT/A

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT05884528

M602011073

Details and patient eligibility

About

The goal of this retrospective, international, multi-center chart abstraction is to learn about the long-term impact of product-specific immunogenicity-related factors in different botulinum neurotoxin type A formulations in patients suffering from cervical dystonia. The main question it aims to answer is:

Do complex-containing (CC) botulinum toxin formulations impact the long-term clinical outcome in cervical dystonia patients compared to a complex-free (CF) formulation?

Researchers will compare differences observed in years 2 and 7 between two toxin groups, i.e., botulinum neurotoxins type A containing complexing proteins (CC) and without complexing proteins (CF).

Full description

Botulinum neurotoxin type A (BoNT/A) is first-line treatment in patients suffering from cervical dystonia. Effect of BoNT/A is temporary and must be repeated to maintain clinical effect. As for all biologics, repeated treatment bears the risk of activating an immune response due to the immunogenic nature of foreign proteins. Clinical signs of a potential immune response are reduced, or loss of efficacy, decreased duration of effect, and the need of a dose increase to maintain effect. Due to the different degree of purity and protein content, it is reasonable to assume that commercial BoNT/A formulations differ in immunogenic properties.

Pivotal clinical trials and monocentric real-world studies demonstrated an increased incidence of neutralizing antibodies (NAbs) and NAb-associated partial or complete secondary non-response. However, the clinical relevance of potential immunogenicity-related mechanisms has not been demonstrated in a larger multicentric cohort in a real-world setting. This chart abstraction is designed to address this gap.

Enrollment: 270 patients

Sex: All

Ages: 18 to 64 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

• Clinical diagnosis of cervical dystonia
• Adults (m/f) 18-64 years of age at start of BoNT/A treatment
• Patient's written informed consent if required by local and/or national law.

Trial design

270 participants in 4 patient groups

Complex-free BoNT/A formulation

Description:

Patients exclusively treated with the complex-free (CF) formulation (incobotulinumtoxinA). A maximum of 328 patients will be enrolled in this group.

Treatment:

Biological: CF BoNT/A

Complex-containing BoNT/A formulations

Description:

Patients exclusively treated with a single complex-containing (CC) formulation (onabotulinumtoxinA or abobotulinumtoxinA). A maximum of 328 patients will be enrolled in this group.

Treatment:

Biological: CC BoNT/A

Switcher CF to CC BoNT/A formulations

Description:

The CF to CC switcher group includes all patients that were switched from a CF to a CC BoNT/A formulation. If more than one switch occurred, the first switch determines the group. Both switcher groups will in sum not exceed 325 patients.

Treatment:

Biological: CF to CC BoNT/A

Switcher CC to CF BoNT/A formulations

Description:

The CC to CF switcher group includes all patients that were switched from a CC to a CF BoNT/A formulation. If more than one switch occurred, the first switch determines the group. Both switcher groups will in sum not exceed 325 patients.

Treatment:

Biological: CC to CF BoNT/A