A Phase 1/2 interventional study of Resiniferatoxin in Intractable Pain and Palliative Care, sponsored by National Institute of Neurological Disorders and Stroke (NINDS). Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 99 Years. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by National Institute of Neurological Disorders and Stroke (NINDS) · Phase 1/2, Interventional, and Treatment
Background:
Cancer-induced bone pain (CIBP) is common in people with cancer. Bone cancer can also lead to anxiety, depression, and reduced mobility and quality of life. Researchers believe a research drug called resiniferatoxin (RTX) may be able to help.
Objective:
To learn whether RTX is safe and can reduce cancer induced bone pain.
Eligibility:
People ages 18 and older with CIBP that is not relieved by standard treatments
Design:
Participants will have up to 6 outpatient visits over about 7 months. These will include:
Medical history
Physical exam
Blood and urine tests.
Thermal testing: a disk placed on the skin to test ability to sense temperature in and around the area of pain
Chest x-ray
EKG: stickers are placed on the chest to measure heart signals
ECG: measures electrical activity of the heart
Participants will have 1 inpatient visit lasting 2-4 days. This will include:
Catheter inserted into a vein in the arm. They are given anesthesia, sedation, and x-ray contrast.
A needle is passed through the skin of the back to inject the RTX.
Participants will keep a log of the pain medications they take after surgery.
Participants will be called 1 week and 2, 3, and 4 months after the injection.
Participants will be mailed surveys and questionnaires to complete 2, 3, and 4 months after the injection.
Cancer-induced bone pain (CIBP) is a common clinical problem. While primary osteosarcoma is relatively uncommon, bone metastases frequently cause cancer-related pain with metastatic spread to bone in 60-84% of cases. Resiniferatoxin (RTX) is an ultrapotent agonist analog of capsaicin that targets a receptor expressed on specific dorsal root sensory ganglia (DRG) neurons and is expected to reduce pain within the targeted zone. The overall program goal is to develop a new treatment for intractable chronic pain below the mid-thoracic level resulting from CIBP that has not been controlled with conservative treatments.
Objectives:
The primary objective it to determine the maximum tolerated dose (MTD) of RTX when injected near one or more DRGs, to characterize its safety/toxicity profile, and to identify any dose-limiting toxicity (DLT). The secondary objectives are to determine the relative change in pain reduction, the change in opioid analgesic consumption and quality of life prior to RTX injection and at the various post RTX timepoints.
Study Population
Up to 30 adult subjects are estimated to be necessary for enrollment to have up to 16 subjects who will receive RTX and provide study-related assessment results through the 30-day time point.
Design
The study is a single center, open-label Phase 1b dose escalation safety and efficacy trial for adult subjects with intractable pain due to CIBP below the mid-thoracic level. Those subjects who meet all inclusion and exclusion criteria will undergo various study procedures and then be scheduled for the unilateral periganglionic (PG) DRG injection(s) (a maximum of 3 contiguous levels) under fluoroscopic guidance to treat the targeted DRGs demonstrated to be responsible for the chronic CIBP. The RTX will be injected at 1 of 4 dose levels, 0.8mcg/DRG, 1.6 mcg/DRG, 3.2 mcg/DRG or 6.4 mcg/DRG. The adaptivedesign algorithm for this study utilizes outcome dependent randomization, a process that selects the dose to be administered to the next subject based on all previous outcomes. In this schema, DLT is the measure that will be used to determine if it is safe to escalate to the next highest dose level.
Subjects who are screen failures and those who prematurely terminate participation will be replaced until 16 subjects have received the injection(s) and completed study-related assessments through the day 30 (D30) timepoint. There is no placebo group because of the invasive nature of the injection and the dose escalation performed in the study.
Outcome Measures
The primary outcome is to achieve a dose-response relationship for safety. All subjects will receive RTX. The secondary outcome measures are: 1) change in NRS and VAS scores at the post-RTX assessments compared to pre RTX assessment, 2) change of opioid usage (in MME) at post RTX assessments compared to pre RTX assessment; 3) comparison SF-36 and BDI at pre RTX injection and Days 14, 37, and 187.
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 RTX treatment and at the post RTX assessment visits) plotted on the y-axis. If, at the end of the study, all dose levels of RTX have equal pain-relieving efficacy, the Data Safety Monitoring Committee (DSMC) may determine if it is appropriate to include a dose lower than 0.8 mcg and/or a control group. On the other hand, if the dose-response curves show that higher doses could result in greater pain-relieving efficacy, the protocol may be amended to include higher doses of RTX.
90 studies on the registry are indexed under Pain, Intractable; 16 are open to participants now.
This study's planned enrollment of 30 is below the median of 60 across 64 interventional studies indexed under Pain, Intractable.
Browse Pain, Intractable studies →National Institute of Neurological Disorders and Stroke (NINDS) is the lead sponsor of 601 studies on the registry; 56 are open to participants now.
Of its 18 completed or terminated interventional studies of FDA-regulated products, 8 (44%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Formal review of the subject s medical records and written approval for his/her inclusion in the study by 3 separate persons:
For women of and men with partners of childbearing potential, the ability and willingness use an effective method of during the study.
Effective methods of birth control include:
EXCLUSION CRITERIA:
Subjects will be excluded from the study if they meet any of the following criteria:
Subjects must not have evidence of a coagulopathy or hemostasis problem as
evidenced by the following blood laboratory values within the week prior to the planned injection:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Schedule a maximum of 3 periganglionic DRG injection(s) at contiguous level(s) to treat targeted DRG responsible for chronic CIBP
Drug: Resiniferatoxin
Resiniferatoxin (RTX) is an ultrapotent agonist analog of capsaicin that targets a receptor expressed on specific dorsal root sensory ganglia (DRG) neurons and is expected to reduce pain within the targeted zone.
To investigate the safety and efficacy of RTX administered intrathecally in subjects with severe refractory pain associated with advanced cancer along with ED100, the MTD, or the maximum dose administered, whichever is achieved first during dose...
The primary study outcome measures are related to safety and toxicity of the investigational agent. The primary study outcome measures are: DLT MTD of RTX
Time frame: Day 7, Day 15, Day 68, Day 188
Improved pain relief through the 180-day time point compared to baseline
The average of the daily worst NRS scores will be used throughout the study for post-injection visits.
Time frame: Completion of study
Substantially reduced (20%) pain at the 30-, 60-. 90-, and 180-day post-treatment time points compared to the pain experienced at baseline
The average of the daily worst NRS scores will be used throughout the study for post-injection visits.
Time frame: Completion of study
Substantially reduced (20%) concomitant opioid analgesic consumption
The average of the daily worst NRS scores will be used throughout the study for post-injection visits.
Time frame: Completion of study
Improved quality of life
The BPI is a validated tool designed to assess the severity of pain and the impact of pain on daily functions in patients with cancer pain and pain due to other chronic diseases.
Time frame: Completion of study
Plan to share: Undecided — We do plan to share IPD. we will share all IPD that results in a publication on a public repository, as required by most journals. the data will be de-identified and anonymized.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Resiniferatoxin
National Institute of Neurological Disorders and Stroke (NINDS) →