Complex Regional Pain Syndrome I (CRPS I)NCT07811362
CRPS-RISE Outcomes Registry
An observational study of Complex Regional Pain Syndrome I (CRPS I), run by Ambros Therapeutics, Inc. at 1 site in United States.
Trial summary
The goal of this observational study is to learn about how well neridronate keeps working in the months after treatment. For 12 or up to 24 months while the registry is open participants will answer online survey questions about their CRPS pain, medication use or procedures done and how CRPS affects what they are able… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Complex Regional Pain Syndrome I (CRPS I)
- Type of treatment
- Injection or infusion
- How many people
- 270 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Sep 2026to 16 Apr 2029
- How long will I take part?
- 12 Months
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The registry target population for provisional enrollment includes all participants in CRPS-RISE, the parent trial of the Registry. After the completion of the last participant's last visit in CRPS-RISE and the unblinding of the trial, the Enrolled Study Cohort will be participants confirmed to have completed a four-infusion course of neridronate. The Enrolled Study Cohort will also include participants in the Open Label Extension study.
Who may be able to join
- Participants from CRPS-RISE
- Completion of four infusions of IP (neridronate 100 mg over a ~ 10-day period [or the renally modified dosing, as applicable] or placebo) in CRPS-RISE .
- Completed CRPS-RISE with a final trial visit at Week 6 (Visit 8) or later.
- Participants who meet both criteria will be provisionally enrolled pending post-trial unblinding and be included in the Provisionally Enrolled Study Cohort.
- After CRPS-RISE last patient last visit unblinding, only participants who meet the following neridronate exposure criterion #3 will continue in registry follow-up and be included in the Enrolled Study Cohort:
- Completion of 4-infusions of neridronate 100 mg over approximately a 10-day period in CRPS-RISE.
Show all 9Show fewer
- Participants from the Open Label Extension (OLE)
- Completion of 4 infusions of neridronate 100 mg over approximately a 10-day period (or the renally modified dosing, as applicable) in the OLE.
- Completed OLE with a final trial visit at Week 6 (Visit 8) or later.
Who cannot join
- There are no exclusion criteria.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
CRPS-RISERegistry
Durham, North Carolina, 27703
CRPS-RiseRegistry CRPS-RiseRegistry, 877-834-5183, CRPS-RiseRegistry@iqvia.com
About this study
Official title: A Prospective Longitudinal Outcomes Registry of Complex Regional Pain Syndrome Type 1 (CRPS-1) in Participants Treated With Neridronate in the CRPS-RISE Trial and/or Open-Label Extension (OLE)
The goal of this observational study is to learn about how well neridronate keeps working in the months after treatment. For 12 or up to 24 months while the registry is open participants will answer online survey questions about their CRPS pain, medication use or procedures done and how CRPS affects what they are able to do.
Read the detailed description
The primary objective of the registry is to evaluate the long-term effectiveness of IV neridronate across three outcome domains in participants who qualified in CRPS-RISE with early, warm CRPS-1 and a positive triple phase bone scan, following prior treatment with four infusions of neridronate 100 mg IV over approximately a 10-day period. The three outcome domains include, patient report of health status, CRPS-1 related clinical events, and disability status.
No neridronate treatment will be given as part of the registry and limited safety information will be collected. Participants will have received neridronate either through CRPS-RISE and/or through the Open Label Extension.
- Keywords
- CRPS 1, Reflex Sympathetic Dystrophy, RDS, CRPS, CRPS Type 1, Complex Regional Pain Syndrome Type 1
- Medical subject headings
- Complex Regional Pain Syndromes, Reflex Sympathetic Dystrophy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Provisionally Enrolled Study Cohort | Participants provisionally enrolled in the registry. (Note: Participants provisionally enrolled who do not meet this neridronate-exposure criterion will not continue registry follow-up.) | |
| Enrolled Study Cohort | Participants who have consented to participate and meet all inclusion criteria including confirmation of completing four infusions of neridronate. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline to each registry assessment of average pain in the past 24 hours.
Average pain (24-hour recall) reported on an 11-point numeric rating scale. This is recorded every 90 days from entry.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Time to loss of benefit where benefit is 50% reduction in average pain intensity from baseline to Week 12 of the CRPS-RISE trial.
Each patient reported registry assessment of average pain in the past 24 hours will use an 11 point numeric rating scale. The analysis will be limited to participants who experienced benefit. Data will be summarized as Kaplan-Meier estimates.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Change from baseline to each registry assessment in CRPS Severity Score Self-Report (CSS-SR) total score and individual items.
The CSS-SR is designed as a patient self-report questionnaire to assess the severity of CRPS signs and symptoms using plain language to assess 13 concepts.
Measured: Every 3 months from entry to up to 24 months of participation.
Change from baseline to each registry assessment in Patient Global Impression of Severity (PGI-S).
The 6-point PGI-S is an overall assessment of the participant's perception of the severity of their CRPS condition at the time of the assessment. Participants will respond to the question "How would you rate the symptoms of your CPRS at this time." Possible responses are scored from 0 to 5 representing none, minimal, mild, moderate, severe, very severe.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Change from baseline to each registry assessment in each of the Short Form 12 Health Survey (SF-12, Acute Version 2) domains, Physical Component Score (PCS), Mental Component Score (MCS), and individual items.
The SF-12 is a widely used measure of general health status used in observational studies across a broad range of disease areas. It is a shortened version of the SF-36 V2.0 and yields 8 domain scores and a Physical Component Summary and Mental Component Summary. Each domain score is calculated by transforming raw responses to a 0-100 scale, where higher scores indicate better health status.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Change from baseline to each registry assessment in Daily Sleep Interference Scale (DSIS) in the past 24 hours on an 11-point numeric rating scale.
The DSIS is a single-item scale that assesses "how much did your pain interfere with your sleep during the past 24 hours?" (0 = did not interfere; 10 = completely interfered
Measured: Every 3 months from enrollment until up to 2 years after entry.
CRPS-1 Related Clinical Events during the 3 months preceding each registry assessment.
The CRPS-1 Treatment Checklist was developed for this registry to assess commonly used pharmacologic treatments (e.g., opioids, neuropathic pain agents, ketamine, NSAIDs, bisphosphonates, corticosteroids, and topicals),interventional procedures (e.g., spinal cord or dorsal root ganglion stimulation, peripheral nerve stimulation, stellate/lumbar sympathetic blocks, sympathetic ablation/sympathectomy, intrathecal pump implant, and Bier block), and non-invasive rehabilitation therapies (e.g., physical therapy, occupational therapy, mirror visual feedback, psychological therapies, scrambler therapies or acupuncture). Participants select all CRPS-related treatments used in the past 3 months. The checklist will also record participation in the open-label clinical trial and is intended for descriptive evaluation of long-term CRPS-1 treatments with a focus on resource intensive events. The outcome domain assesses the long-term effectiveness of neridronate through patient reports.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Disability Status
During the 3 months preceding each registry assessment the participant reported applying for or being on short-term disability, long-term disability, or workers compensation. As a binary endpoint, it will be summarized as frequencies and percentages. The domain assesses the long-term effectiveness of neridronate through patient reports of short-term disability, long-term disability, and workers compensation.
Measured: Every 3 months from enrollment until up to 2 years after entry.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2026
- Study start17 Sep 2026 (estimated)
- Primary completion16 Apr 2029 (estimated)
- Study completion16 Apr 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Complex Regional Pain Syndrome I (CRPS I)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 270 participants (estimated)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- Ambros Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Joel Castellanos, MD, Principal investigator, UCSD
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07811362
- Sponsor's protocol ID
- AMBTX-01-R01
- Status last verified
- Sep 2026
- First submitted
- 31 Aug 2026
- Last updated
- 29 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Prospective Longitudinal Outcomes Registry of Complex Regional Pain Syndrome Type 1 (CRPS-1) in Participants Treated With Neridronate in the CRPS-RISE Trial and/or Open-Label Extension (OLE)
- ClinicalTrials.gov ID
- NCT07811362
- Acronym / sponsor ID
- AMBTX-01-R01
- Keywords
- CRPS 1, Reflex Sympathetic Dystrophy, RDS, CRPS, CRPS Type 1, Complex Regional Pain Syndrome Type 1
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 270 participants (estimated)
- Lead sponsor
- Ambros Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 17 Sep 2026 (estimated)
- Primary completion
- 16 Apr 2029 (estimated)
- Study completion
- 16 Apr 2029 (estimated)
- First posted
- 10 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this observational study is to learn about how well neridronate keeps working in the months after treatment. For 12 or up to 24 months while the registry is open participants will answer online survey questions about their CRPS pain, medication use or procedures done and how CRPS affects what they are able to do.
Detailed description
The primary objective of the registry is to evaluate the long-term effectiveness of IV neridronate across three outcome domains in participants who qualified in CRPS-RISE with early, warm CRPS-1 and a positive triple phase bone scan, following prior treatment with four infusions of neridronate 100 mg IV over approximately a 10-day period. The three outcome domains include, patient report of health status, CRPS-1 related clinical events, and disability status.
No neridronate treatment will be given as part of the registry and limited safety information will be collected. Participants will have received neridronate either through CRPS-RISE and/or through the Open Label Extension.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Target follow-up
- 12 Months
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Provisionally Enrolled Study Cohort | – | –Participants provisionally enrolled in the registry. (Note: Participants provisionally enrolled who do not meet this neridronate-exposure criterion will not continue registry follow-up.) |
| Enrolled Study Cohort | – | –Participants who have consented to participate and meet all inclusion criteria including confirmation of completing four infusions of neridronate. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The registry target population for provisional enrollment includes all participants in CRPS-RISE, the parent trial of the Registry. After the completion of the last participant's last visit in CRPS-RISE and the unblinding of the trial, the Enrolled Study Cohort will be participants confirmed to have completed a four-infusion course of neridronate. The Enrolled Study Cohort will also include participants in the Open Label Extension study.
Key inclusion criteria (9 listed)
- Participants from CRPS-RISE
- Participants who meet both criteria will be provisionally enrolled pending post-trial unblinding and be included in the Provisionally Enrolled Study Cohort.
- After CRPS-RISE last patient last visit unblinding, only participants who meet the following neridronate exposure criterion #3 will continue in registry follow-up and be included in the Enrolled Study Cohort:
- Participants from the Open Label Extension (OLE)
Key exclusion criteria (1 listed)
- There are no exclusion criteria.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change from baseline to each registry assessment of average pain in the past 24 hours.
Time frame: Every 3 months from enrollment until up to 2 years after entry.
Average pain (24-hour recall) reported on an 11-point numeric rating scale. This is recorded every 90 days from entry.
Time to loss of benefit where benefit is 50% reduction in average pain intensity from baseline to Week 12 of the CRPS-RISE trial.
Time frame: Every 3 months from enrollment until up to 2 years after entry.
Each patient reported registry assessment of average pain in the past 24 hours will use an 11 point numeric rating scale. The analysis will be limited to participants who experienced benefit. Data will be summarized as Kaplan-Meier estimates.
Change from baseline to each registry assessment in CRPS Severity Score Self-Report (CSS-SR) total score and individual items.
Time frame: Every 3 months from entry to up to 24 months of participation.
The CSS-SR is designed as a patient self-report questionnaire to assess the severity of CRPS signs and symptoms using plain language to assess 13 concepts.
Change from baseline to each registry assessment in Patient Global Impression of Severity (PGI-S).
Time frame: Every 3 months from enrollment until up to 2 years after entry.
The 6-point PGI-S is an overall assessment of the participant's perception of the severity of their CRPS condition at the time of the assessment. Participants will respond to the question "How would you rate the symptoms of your CPRS at this time." Possible responses are scored from 0 to 5 representing none, minimal, mild, moderate, severe, very severe.
Change from baseline to each registry assessment in each of the Short Form 12 Health Survey (SF-12, Acute Version 2) domains, Physical Component Score (PCS), Mental Component Score (MCS), and individual items.
Time frame: Every 3 months from enrollment until up to 2 years after entry.
The SF-12 is a widely used measure of general health status used in observational studies across a broad range of disease areas. It is a shortened version of the SF-36 V2.0 and yields 8 domain scores and a Physical Component Summary and Mental Component Summary. Each domain score is calculated by transforming raw responses to a 0-100 scale, where higher scores indicate better health status.
Change from baseline to each registry assessment in Daily Sleep Interference Scale (DSIS) in the past 24 hours on an 11-point numeric rating scale.
Time frame: Every 3 months from enrollment until up to 2 years after entry.
The DSIS is a single-item scale that assesses "how much did your pain interfere with your sleep during the past 24 hours?" (0 = did not interfere; 10 = completely interfered
CRPS-1 Related Clinical Events during the 3 months preceding each registry assessment.
Time frame: Every 3 months from enrollment until up to 2 years after entry.
The CRPS-1 Treatment Checklist was developed for this registry to assess commonly used pharmacologic treatments (e.g., opioids, neuropathic pain agents, ketamine, NSAIDs, bisphosphonates, corticosteroids, and topicals),interventional procedures (e.g., spinal cord or dorsal root ganglion stimulation, peripheral nerve stimulation, stellate/lumbar sympathetic blocks, sympathetic ablation/sympathectomy, intrathecal pump implant, and Bier block), and non-invasive rehabilitation therapies (e.g., physical therapy, occupational therapy, mirror visual feedback, psychological therapies, scrambler therapies or acupuncture). Participants select all CRPS-related treatments used in the past 3 months. The checklist will also record participation in the open-label clinical trial and is intended for descriptive evaluation of long-term CRPS-1 treatments with a focus on resource intensive events. The outcome domain assesses the long-term effectiveness of neridronate through patient reports.
Disability Status
Time frame: Every 3 months from enrollment until up to 2 years after entry.
During the 3 months preceding each registry assessment the participant reported applying for or being on short-term disability, long-term disability, or workers compensation. As a binary endpoint, it will be summarized as frequencies and percentages. The domain assesses the long-term effectiveness of neridronate through patient reports of short-term disability, long-term disability, and workers compensation.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Sep 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Joel Castellanos, MD principal investigator
UCSD
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Complex Regional Pain Syndrome I (CRPS I), run by Ambros Therapeutics, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact CRPS-RiseRegistry (877-834-5183, CRPS-RiseRegistry@iqvia.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline to each registry assessment of average pain in the past 24 hours. (time frame: Every 3 months from enrollment until up to 2 years after entry.). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Sep 2026.