Resiniferatoxin for Chronic Pain

Not yet recruiting at 1 trial location

Overseen By John D Heiss, M.D.

Age: 18+

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: National Institute of Neurological Disorders and Stroke (NINDS)

Must be taking: Opioids

Must not be taking: Anticoagulants, Factor Xa inhibitors

Disqualifiers: ECG abnormality, Allergy to capsaicin, Coagulopathy, Pregnancy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 8

Duration: 2-4 days

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called resiniferatoxin (RTX) to determine if it can safely reduce chronic pain from cancer spreading to the bones. Bone cancer pain can be difficult to manage and often affects how people feel and move. This trial may suit those 18 and older with cancer-related bone pain unresponsive to standard treatments. Participants will attend several outpatient visits and have one short hospital stay to receive the treatment and complete various tests and surveys. As a Phase 1 trial, the research focuses on understanding how the treatment works in people, offering participants a chance to be among the first to receive this new treatment.

Do I need to stop taking my current medications for the trial?

You may need to stop taking certain medications like aspirin, non-steroidal anti-inflammatory drugs, or vitamin E at least 7 days before surgery. If you're on a blood thinner like Xarelto, you might need to adjust your dose or consult a specialist. Other medications are not specifically mentioned, so it's best to discuss with the trial team.

Is there any evidence suggesting that resiniferatoxin is likely to be safe for humans?

Research has shown that resiniferatoxin (RTX) is generally well-tolerated. In one study, RTX was safe in single doses up to 8 mg, with participants not experiencing severe side effects. Another study found that RTX can reduce pain by targeting specific nerve cells without causing widespread harm.

While researchers continue to study RTX for safety and effectiveness, evidence so far suggests it is well-tolerated. If the FDA has approved RTX for other uses, it indicates some level of safety. However, as this is an early-phase trial, more information is needed about its safety in humans. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Resiniferatoxin is unique because it targets chronic pain in a new way by using a potent compound derived from a cactus-like plant. Unlike standard pain treatments that often rely on opioids or non-steroidal anti-inflammatory drugs, resiniferatoxin works by desensitizing the sensory nerves responsible for transmitting pain signals. This approach could provide long-lasting relief with potentially fewer side effects, making it an exciting prospect for those suffering from chronic pain conditions. Researchers are particularly interested in its ability to reduce pain through direct injections at the source, offering a targeted and innovative solution.

What evidence suggests that resiniferatoxin might be an effective treatment for cancer-induced bone pain?

Research has shown that resiniferatoxin (RTX), the treatment under study in this trial, can greatly reduce bone pain caused by cancer. In earlier studies, a single injection of RTX led to a 38% reduction in the worst pain reported by patients. Participants also required 57% less opioid medication, indicating strong pain relief. RTX improved patients' overall quality of life as well. These findings suggest that RTX could effectively manage chronic pain in people with cancer. ^{1 6 7 8 9}

Who Is on the Research Team?

John D Heiss, M.D.

Principal Investigator

National Institute of Neurological Disorders and Stroke (NINDS)

Are You a Good Fit for This Trial?

Adults over 18 with severe bone pain due to cancer, not relieved by standard treatments. Participants must be in stable health, able to undergo medical procedures and willing to stop certain medications before surgery. Women of childbearing age and men with partners of childbearing potential must use contraception.

Inclusion Criteria

I am willing to stop or adjust my medication as advised before surgery.

Formal review of the subject's medical records and written approval for his/her inclusion in the study by 3 separate persons.

I am willing and able to have an eye exam.

Exclusion Criteria

You should not have any spinal cord or spinal space issues that could make it risky to insert a needle.

Your electrolyte levels must be normal or can be fixed.

Subjects must not have an allergy or hypersensitivity to certain substances.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Treatment

Participants receive periganglionic DRG injection(s) of RTX under fluoroscopic guidance

2-4 days

1 inpatient visit

Follow-up

Participants are monitored for safety and effectiveness after treatment

6 months

Up to 6 outpatient visits, plus phone calls and mailed surveys

Long-term follow-up

Participants' pain relief and opioid consumption are assessed at multiple time points

180 days

What Are the Treatments Tested in This Trial?

Interventions

• Resiniferatoxin

Trial Overview The trial is testing Resiniferatoxin (RTX) for reducing severe cancer-induced bone pain. It involves outpatient visits for tests like EKG and thermal testing, a short hospital stay for RTX injection, keeping a medication log post-surgery, and completing surveys after the treatment.

How Is the Trial Designed?

Group I: Resiniferatoxin Experimental Treatment 1 Intervention

Schedule a maximum of 3 periganglionic DRG injection(s) at contiguous level(s) to treat targeted DRG responsible for chronic CIBP

Who Is Running the Clinical Trial?

National Institute of Neurological Disorders and Stroke (NINDS)

Lead Sponsor

Trials

1,403

Recruited

655,000+

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT02522611

NCT02522611 | Periganglionic Resiniferatoxin for the ... The efficacy outcome variable will be evaluated by establishing dose-response curves, with dose plotted on the x-axis and changes in efficacy endpoints (before ...

2. nih.gov nih.gov/news-events/news-releases/nih-scientists-pioneer-promising-treatment-intractable-cancer-pain

NIH scientists pioneer promising treatment for intractable ... A single injection of RTX provided patients durable relief. Patients' need for pain-relieving opioids declined sharply, and their quality of ...

3. evidence.nejm.org evidence.nejm.org/doi/abs/10.1056/EVIDoa2400423

Treatment of Intractable Cancer Pain with Resiniferatoxin The primary outcome was safety. Secondary outcomes were efficacy assessed over the course of the study using a numerical rating scale measuring ...

4. medcentral.com medcentral.com/pain/single-dose-rtx-shows-promise-in-intractable-cancer-pain

Single-Dose RTX Shows Promise in Intractable Cancer Pain The results indicated that RTX led to a 38% reduction in reported “worst” pain outcomes and a 57% decrease in opioid consumption among the 15 ...

5. ascopost.com ascopost.com/news/june-2025/treatment-for-intractable-cancer-pain-pioneered/

Treatment for Intractable Cancer Pain Pioneered A single injection of resiniferatoxin provided patients with durable relief, and their quality of life improved. The researchers found that ...

6. safety.duke.edu safety.duke.edu/sites/default/files/SOP-Template-Resiniferatoxin.docx

SOP Template for working with Resiniferatoxin RTX is incompatible with strong oxidizers, according to the safety data sheet (SDS). 8. If personnel are exposed/injured, follow “First Aid/Exposure Response”.

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4711370/

Resiniferatoxin for Pain Treatment: An Interventional ... This review examines existing preclinical and clinical studies related to resiniferatoxin (RTX) and its potential uses in pain treatment.

8. oarsijournal.com oarsijournal.com/article/S1063-4584(24)00351-0/fulltext

Preliminary evaluation of the safety and analgesic effect ... RTX was found to be safe and well tolerated following single IA doses up to 8 mg (Euphorbia resinifera latex in the injectate solution) and with up to two ...

9. jpain.org jpain.org/article/S1526-5900(14)00303-4/fulltext

(364) A Phase I study of the intrathecal administration ... These preliminary findings suggest that intrathecal injection of RTX can selectively and irreversibly delete neurons that transmit pain. We plan to test the ...