IV neridronate for warm-type Complex Regional Pain Syndrome (CRPS-1) with a positive bone scan

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This multicenter, randomized, triple-blind, placebo-controlled Phase 3 trial gives 400 mg IV neridronate on Days 1, 4, 7, and 10 to adults with the warm subtype of CRPS-1 and a positive triple-phase bone scan. Eligible participants have a single affected limb, CRPS symptoms for six months or less, and meet Budapest clinical criteria without known peripheral nerve injury. Each participant will be in the program for up to about 18 weeks including up to 6 weeks of screening and follow-up through Week 12. The trial compares neridronate against placebo for effects on pain, edema, function, and safety.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Male or female participant ≥ 18 years of age at time of Screening.
2. A diagnosis of CRPS-1 according to the clinical Budapest Criteria as recommended by the International Association for the Study of Pain (IASP), as well as no known peripheral nerve injury. Signs and symptoms of CRPS must apply to a single identified affected limb (i.e., arm, hand, wrist, leg, ankle or foot) and must demonstrate asymmetry with respect to the contralateral limb.
3. Single affected limb at the Screening and Randomization Visits meeting the following warm subtype criteria:

   1. Edema in the affected limb
   2. AND ≥ 2 of the following:

      1. Obvious redness in the affected region relative to the same region on the contralateral limb on inspection
      2. ≥ 1°C increase in temperature on the affected limb relative to the contralateral limb
      3. Moderate-to-severe edema
4. ≤ 6 months since the onset of CRPS symptoms relative to the Randomization visit
5. Increased uptake in the involved limb compared to the contralateral limb on TPBS (phase 2 and/or phase 3) during Screening. A historic scan not older than 3 months prior to Randomization Visit is acceptable, if available and of sufficient quality for a central read.
6. Women of childbearing potential must:

   1. Be nonpregnant.
   2. Be nonlactating.
   3. Agree to use a highly effective method of contraception and for at least 6 months following last investigational product administration.

   Exception: Women exclusively engaging in same sex sexual activities are not required to meet this criterion.
7. Adequate compliance with the eDiary during the screening period.

Exclusion Criteria

1. A current or prior diagnosis of CRPS Type 2 or CRPS not otherwise specified (CRPS NOS), or whose CRPS has no known inciting event, or CRPS-1 without criteria of the warm subtype at the time of Screening.
2. ≥ 40 points on the Pain Catastrophizing Scale.
3. Prior use of neridronate or participation in a clinical study where the participant may have received neridronate.
4. The use of any of the following treatments within the timeframe specified from Randomization Visit:

   1. Within the last 12 months:

      * IV bisphosphonates
      * IV immunoglobulin
   2. Within the last 6 months:

      * Any oral bisphosphonate, denosumab (Prolia®) or receptor activator of nuclear factor kappa B ligand (RANKL) inhibitors (e.g., denosumab biosimilar compounds)
      * Calcitonin
      * Ketamine
      * Radiation therapy to the head or neck
5. Participants currently taking or planning to be treated with prohibited concomitant medications/therapies, or not likely able to follow the protocol restrictions for use of concomitant treatment.
6. Severely impaired renal function.
7. Hypocalcemia.
8. Vitamin D deficiency.
9. Significant dental findings such as an unhealed tooth extraction site.
10. Eye inflammation.
11. Significantly elevated liver-related lab tests or evidence of significant liver disease.
12. Clinically unstable cardiac disease.
13. Any known conditions, from 3 months prior to Screening Visit or to the Randomization Visit, that may interfere with the assessment of CRPS-1, CRPS-related pain, safety, or other trial assessments.

Where it's running

• Ambros Clinical Trial Site
  Phoenix, Arizona, United States Recruiting
• Ambros Clinical Trial Site
  Tucson, Arizona, United States Recruiting
• Ambros Clinical Trial Site
  Little Rock, Arkansas, United States Recruiting
• Ambros Clinical Trial Site
  La Jolla, California, United States Recruiting
• Ambros Clinical Trial Site
  Napa, California, United States Recruiting
• Ambros Clinical Trial Site
  Pasadena, California, United States Recruiting

Study contacts

• Study coordinator: Medical Affairs
• Email: Medinfo@ambrostx.com
• Phone: +1 949-508-0173

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Neridronate extension study for CRPS-1

  This study tests IV neridronate in people with CRPS-1 who completed a previous trial, to see if it continues to help with pain and symptoms.

  Recruiting Phase 3 Ambros Therapeutics, Inc. · Phoenix, Arizona · NCT07857733

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• Understanding how a wrist fracture heals and why some people develop long-lasting pain

  This study tests whether genetic markers, blood signals, heart-rate patterns, and brain body maps can predict which patients will have persistent pain after a distal radius fracture.

  Recruiting Cambridge University Hospitals NHS Foundation Trust · Cambridge, Cambridgeshire · NCT07777081

• Hyperbaric oxygen therapy for severe CRPS

  This trial tests whether adding hyperbaric oxygen therapy helps people with severe complex regional pain syndrome compared with a delayed-start approach.

  Recruiting at 2 sites University Hospital Ostrava · Ostrava, Moravian-Silesian Region and 1 other locations · NCT07446712

• Effects of a high CBD cannabis extract on pain in Complex Regional Pain Syndrome

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  Recruiting at 2 sites Phase 1 University of California, San Diego · La Jolla, California and 1 other locations · NCT06393101

• Using low-dose naltrexone to relieve pain in complex regional pain syndrome

  This study is testing if low-dose naltrexone can help people with complex regional pain syndrome feel less pain.

  Recruiting Stanford University · Palo Alto, California · NCT02502162

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.