Open Label Extension Study To Investigate Long Term Safety, Tolerability And Efficacy Of Pf-02545920 In Subjects With Huntington's Disease Who Completed Study A8241021

Pfizer

Status and phase: Terminated; Phase 2

Conditions: Huntington's Disease

Treatments: Drug: 20 mg BID of PF-02545920

Study type: Interventional

Funder types: Industry

Identifiers

NCT02342548

2014-004900-31 (EudraCT Number)

OPEN LABEL TO A8241021 (Other Identifier)

A8241022

Details and patient eligibility

About

This study is a 12 month open label extension study of PF-02545920 20 mg dosed BID following study A8241021 in subjects with HD. Primary endpoints will be to assess long-term safety and tolerability of 20 mg BID of PF-02545920. Secondary endpoints will be the change from baseline in the Total Motor Score (TMS)assessment, and/ior the Total maximum Chorea (TMC) assessment of the Unified Huntington Disease Rating Scale (UHDRS) after 6 and 12 months of treatment, and Clinical Global Impression-Improvement score after 6 and 12 months of treatment. Subjects, who were assigned to the 20 mg PF-02545920 dose group in the preceding A8241021 study, will receive 20 mg PF-02545920 without any titration. All other subjects will be titrated to the 20 mg BID dose as follows: 5 mg BID for 7 days, 10 mg BID for 7 days, 15 mg BID for 7 days, then 20 mg BID for the remainder of the treatment phase. Up to 260 subjects may take part in this open label extension

Enrollment: 188 patients

Sex: All

Ages: 30 to 66 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Subjects must have completed study A8241021
• Diagnosis of HD, including ≥36 CAG repeats.

Exclusion criteria

• Significant neurological disorder other than Huntington's disease.
• WBC ≤ 3500/mm3 AND/OR ANC ≤ 2000/mm3 and history of neutropenia or myeolo-proliferative disorders.
• Any drug related SAE experienced during study A8241021 which were not approved as acceptable for enrollment in A8241022.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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188 participants in 2 patient groups

20 mg BID PF-02545920 non-titrated

Experimental group

Description:

Subjects who received 20 mg BID in completed study A8241021 will continue to receive 20 mg BID PF-02545920

Treatment:

Drug: 20 mg BID of PF-02545920

20mg BID PF-02545920 titrated

Experimental group

Description:

Subjects who received either Placebo or 5mg BID of PF-02545920 in completed study A8241021 will be titrated up to 20 mg with 5mg increment per week, over 4 weeks (5mg increment/wk)

Treatment:

Drug: 20 mg BID of PF-02545920