Conditions: Chronic Migraine
Keywords: Botox OnabotulinumtoxinA Chronic Migraine Calcitonin Gene-Related Peptide Saliva
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 20
Healthy volunteers: no

Brief summary:
Twenty patients will be enrolled in a 2-site, 7-month, double-blind study conducted to evaluate a reduction in headache days and attacks and calcitonin gene-related peptide (CGRP) levels in saliva following treatment with OnabotulinumtoxinA versus saline.

Eligible patients will be randomized and receive injections of OnabotulinumtoxinA or Saline at Visit 1. Following 3 months plus a 1 month wash out, patients will receive cross-over injections at Visit 5.

Patients will return for monthly visits and exit the study at Visit 8.

Patients will collect saliva at monthly intervals and document in a daily headache diary throughout the study .

Detailed description:
This double-blind study will evaluate reduction in number of headache days following treatment with OnabotulinumtoxinA versus Saline. Additionally, CGRP levels in saliva will be correlated with a reduction in headache attacks.

At Visit 1, eligible subjects will be randomized 1:1 to receive injections of OnabotulinumtoxinA or Saline in an identical manner. Subjects will collect 3 saliva samples during each month of the 7 month study: 1 collection at Baseline headache level, 1 collection at onset of headache that is one degree worse than Baseline level that will be treated with acute therapy, and 1 collection at 2 hours following treatment. Subjects will document headache and headache symptoms in a daily diary and return to the clinic with diary and saliva samples at monthly visits.

Following 4 months (including a 1 month washout after Visit 4), subjects will return at Visit 5 and receive cross-over injections. Subjects randomized to OnabotulinumtoxinA at Visit 1 will receive injections of Saline. Subjects randomized to saline at Visit 1 will receive injections of OnabotulinumtoxinA. Subjects will document headache and headache symptoms in a daily diary and return to the clinic with diary and saliva samples at monthly visits.

At Visit 8, 3 months following re-injection at Visit 5, subjects will exit the study.

Arms:
arm 1: Minimum dose of 155 international units (U) OnabotulinumtoxinA Purified Neurotoxin Complex administered at 31 fixed-site, fixed-dose injections across seven specific head/neck muscle areas. arm 2: 155 U Saline administered at 31 fixed-site, fixed-dose injections across seven specific head/neck muscle areas.

Interventions: intervention 1: OnabotulinumtoxinA intervention 2: Saline
Intervention descriptions: intervention 1: Minimum dose of 155 U OnabotulinumtoxinA Purified Neurotoxin Complex administered at 31 fixed-site, fixed-dose injections across seven specific head/neck muscle areas. Subjects will continue to monitor headache symptoms with a headache diary and collect saliva samples as instructed.

At investigator's discretion, additional 40 U OnabotulinumtoxinA Purified Neurotoxin Complex may be administered unilaterally or bilaterally, using follow-the-pain paradigm. intervention 2: 155 U Saline administered at 31 fixed-site, fixed-dose injections across seven specific head/neck muscle areas. Subjects will continue to monitor headache using a headache diary and collect saliva samples as instructed.

At investigator's discretion, additional Saline may be administered unilaterally or bilaterally, using follow-the-pain paradigm.

Protocol document: