Efficacy of Riluzole in Surgical Treatment for Cervical Spondylotic Myelopathy (CSM-Protect)

• riluzole (Drug), also known as Rilutek: 50mg BID orally for 14 days prior to surgery and 28 days after the surgery
• Placebo medication (Drug): 50mg BID orally for 14 days prior to surgery and 28 days after the surgery

Primary outcomes

• Modified Japanese Orthopedic Association Score (mJOA) [Before the surgery, 180 days]: The mJOA is a clinician administered scale. It evaluates four clinical dimensions; motor dysfunction score for upper and lower extremities, sensation loss and sphincter dysfunction. The total score ranges from 0 (worst) to 18 (best).

Secondary outcomes

• Nurick Score [Pre-surgical, 180 days]: Nurick score is a simple measure of neurological dysfunction and ranges from 0 (best) to 6 (worst).
• SF-36v2.0 [Before the surgery, 180 days]: The SF36v2.0 is a health-related quality of life instrument that evaluates health status accross eight health dimensions.
• Neck Disability Index (NDI) [Before the surgery, 180 days]: The NDI evaluates patient self-reported functional outcomes related to neck conditions. The NDI score ranges from 0 (best) to 100 (worst).
• Cervical Pain Numeric Rating Scale [Before the surgery, 180 days]: Simple numeric rating scale with choises of answers from 0 (no pain) to 10 (worst imaginable pain)
• EQ-5D [Before the surgery, 180 days]: EQ-5D™ is a standardised instrument for use as a measure of health outcome. It provides a simple descriptive profile and a single index value for health status.
• American Spinal Injury Association Score (ASIA) [Before the surgery, 180 days]: The ASIA impairment scale describes a person's functional impairment as a result of their spinal cord injury.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Age between 18 and 80 years
* Diagnosis of symptomatic cervical spondylotic myelopathy defined as a combination of:

  1. one or more of the following symptoms:

     * Numb hands
     * Clumsy hands
     * Impairment of gait
     * Bilateral arm paresthesiae
     * l'Hermitte's phenomena
     * Weakness And,
  2. one or more of the following signs:

     * Corticospinal distribution motor deficits
     * Atrophy of hand intrinsic muscles
     * Hyperreflexia
     * Positive Hoffman sign
     * Upgoing plantar responses
     * Lower limb spasticity
     * Broad based, unstable gait And,
  3. MRI evidence of cervical spondylotic myelopathy
* Scheduled for an elective surgery for cervical spondylotic myelopathy
* Preoperative mJOA score ≥8 and ≤14
* Women of child bearing potential must be:

  * Postmenopausal defined as amenorrhea for at least 2 years.
  * Surgically sterile, (have had a hysterectomy or bilateral oophorectomy, tubal ligation, or otherwise be incapable of pregnancy)
  * Abstinent (at the discretion of the investigator)
  * Having other congenital or medical condition that prevents subject from becoming pregnant
  * If sexually active, be practicing an effective method of birth control such as hormonal prescription oral contraceptives, progesterone implants or injections, intrauterine device (IUD), or male partner with a vasectomy. A double-barrier method such as condoms, diaphragms or cervical caps with spermicidal foam, cream or gel may be used as a birth control method.
  * Women of childbearing potential must have a negative serum β-human chorionic gonadotropin (β-hCG) pregnancy test or a negative urine pregnancy test at screening before the first dose of study drug is received.

Exclusion Criteria:

* Previous surgery for CSM
* Concomitant symptomatic lumbar stenosis
* CSM symptoms due to cervical trauma (at the discretion of the investigator)
* Hypersensitivity to riluzole or any of its components
* Neutropenia measured as absolute neutrophil count (ANC) measured in cells per microliter of blood of < 1500 at screening visit
* Creatinine level of > 1.2 milligrams (mg) per deciliter (dl) in males or > 1.1 milligrams per deciliter in females at screening visit Liver enzymes (ALT or AST) 3x higher than normal values at screening visit.
* Liver enzymes (ALT or AST) 3x higher than normal values at screening visit.
* Subject will be using any of the following medications which are classified as CYP1A2 inhibitors or inducers*during the course of the drug regimen:

Inhibitors:

* Ciprofloxacin
* Enoxacin
* Fluvoxamine
* Methoxsalen
* Mexiletine
* Oral contraceptives
* Phenylpropanolamine
* Thiabendazole
* Zileuton

Inducers:

* Montelukast
* Phenytoin

  *Note: no washout period required; if these medications are discontinued, subjects are eligible to be enrolled in the trial.
* Systemic infection such as AIDS, HIV, and active hepatitis
* Active malignancy defined as history of invasive malignancy, except if the patient has received treatment and displayed no clinical signs and symptoms for at least five years
* Recent history (less than 3 years) of chemical substance dependency or significant psychosocial disturbance that may impact the outcome or study participation
* Breastfeeding at screening visit and plan to continue during the course of the study drug
* Unlikely to comply with the follow-up evaluation schedule
* Unlikely to comply with investigational drug regime
* Participation in a clinical trial of another investigational drug or device within the past 30 days
* Is a prisoner
* Unable to converse, read or write English at elementary school level

• Fehlings MG, Wilson JR, Karadimas SK, Arnold PM, Kopjar B. Clinical evaluation of a neuroprotective drug in patients with cervical spondylotic myelopathy undergoing surgical treatment: design and rationale for the CSM-Protect trial. Spine (Phila Pa 1976). 2013 Oct 15;38(22 Suppl 1):S68-75. doi: 10.1097/BRS.0b013e3182a7e9b0. PMID 23962993
• Results publication: Bak AB, Moghaddamjou A, Arnold PM, Harrop JS, Fehlings MG. Chronic pain after decompression for degenerative cervical myelopathy: a pooled trajectory analysis of individual participant data. Pain. 2026 Mar 1;167(3):654-662. doi: 10.1097/j.pain.0000000000003828. Epub 2025 Oct 15. PMID 41086299
• Results publication: Wong R, Alvi MA, Quddusi AI, Fehlings MG. Role of Neck Pain in Defining Clinical Trajectories of Outcomes in Patients With Degenerative Cervical Myelopathy: Results of a Novel Machine Learning Algorithm. Global Spine J. 2026 Jan;16(1):218-229. doi: 10.1177/21925682251341263. Epub 2025 May 10. PMID 40347099
• Results publication: Pedro KM, Alvi MA, Hejrati N, Moghaddamjou A, Fehlings MG. Elderly Patients Show Substantial Improvement in Health-Related Quality of Life After Surgery for Degenerative Cervical Myelopathy Despite Medical Frailty: An Ambispective Analysis of a Multicenter, International Data Set. Neurosurgery. 2024 Jun 1;94(6):1122-1131. doi: 10.1227/neu.0000000000002818. Epub 2024 Jan 10. PMID 38197642
• Results publication: Fehlings MG, Badhiwala JH, Ahn H, Farhadi HF, Shaffrey CI, Nassr A, Mummaneni P, Arnold PM, Jacobs WB, Riew KD, Kelly M, Brodke DS, Vaccaro AR, Hilibrand AS, Wilson J, Harrop JS, Yoon ST, Kim KD, Fourney DR, Santaguida C, Massicotte EM, Kopjar B. Safety and efficacy of riluzole in patients undergoing decompressive surgery for degenerative cervical myelopathy (CSM-Protect): a multicentre, double-blind, placebo-controlled, randomised, phase 3 trial. Lancet Neurol. 2021 Feb;20(2):98-106. doi: 10.1016/S1474-4422(20)30407-5. Epub 2020 Dec 22. PMID 33357512

• Michael Fehlings, MD, Principal investigator, University Health Network, Toronto
• Branko Kopjar, MD, Study director, University of Washington