TNP are a considerable burden and affects significantly the quality of life of the sufferer. There are medications for their management but while they may work for some patients, may not work for the others; in addition, side effects may be present for some patients with the need to decrease dosage to not optimal levels. Furthermore, the indications of these drugs are for other neuropathic pain disorders and currently there is no medication specifically indicated for the management of TNP based on its molecular pathophysiology.
The calcitonin gene-related peptide (CGRP) is a key neuropeptide involved in migraine pathophysiology. There is evidence showing that CGRP has a role in other disorders mediated by the trigeminal system in addition to migraine; CGRP has shown to have a role in orofacial pain such as in TMD and in trigeminal neuropathic pain. Erenumab-aooe is the first antibody therapeutic targeting the CGRP receptor with FDA approval for migraine prevention that is well tolerated and with a good safety profile. Therefore, the scientific premise for this study is that inhibiting the CGRP pathway in trigeminal neuropathic pain will decrease pain and pain related outcomes in a safe and well tolerated manner for this patient population.
Potential participants will be pre-screened at the Brotman Facial Pain clinic, at the Oral and Maxillofacial Surgery Clinic both at the University of Maryland, School of Dentistry, at the Pain Medicine Clinic at the University of Maryland, School of Medicine or by telephone; those willing to participate will be scheduled for a screening and baseline visit (Visit 0). During this visit, potential participants will be evaluated for eligibility for trigeminal neuropathic pain (subjects with diagnosis based on the International classification of headache disorders ICHD-3 and International classification of Orofacial Pains ICOP of idiopathic trigeminal neuralgia with concomitant continuous pain, painful posttraumatic trigeminal neuropathy or idiopathic painful trigeminal neuropathy) and written informed consent will be obtained. The screening and baseline procedures include medical history review, clinical examinations, tests and administration of questionnaires. Instructions will be given for the completion of a Daily Symptom Diary (DSD) and other questionnaires at home or online. Participants who show compliance with 80 % completion of the DSD and who meet the pain score (inclusion criteria) for 4 weeks/28 days during the baseline period from Visit 0, will be randomly assigned to one of two groups either the investigational drug or placebo and will be scheduled for Visit 1.
The study drug is Erenumab 140 mg, SC injection. Participants will attend 6 clinic visits (Visit 0-Visit 5). After randomization and on Visit 1, the participant will receive the drug or placebo. This same treatment will be administered once a month for 3 months (3 cycles/12weeks).
