NCT03990649 is a Phase 2 clinical trial of Soticlestat in Complex Regional Pain Syndrome, sponsored by Millennium Pharmaceuticals, Inc..

Who is sponsoring NCT03990649?

NCT03990649 is sponsored by Millennium Pharmaceuticals, Inc..

What drugs are being tested in NCT03990649?

Interventions in NCT03990649: Soticlestat, Placebo.

What condition does NCT03990649 study?

NCT03990649 studies Complex Regional Pain Syndrome.

Is NCT03990649 still recruiting?

NCT03990649 is currently completed. Last updated 15 July 2021.

Are results published for NCT03990649?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2021-07-15 · How we verify

NCT03990649

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

Study of TAK-935 as an Adjunctive Therapy in Adult Participants With Complex Regional Pain Syndrome (CRPS)

Completed Phase 2 Results posted Last updated 15 July 2021

What this trial tests

Phase 2 trial testing Soticlestat in Complex Regional Pain Syndrome in 24 participants. Completed in 28 October 2020.

Timeline

23 July 2019

Primary endpoint
29 June 2020

28 October 2020

Quick facts

Lead sponsor	Millennium Pharmaceuticals, Inc.
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	quadruple
Primary purpose	treatment
Enrollment	24
Start date	23 July 2019
Primary completion	29 June 2020
Estimated completion	28 October 2020
Sites	3 locations across United Kingdom

Drugs / interventions tested

Soticlestat — full drug profile →
Placebo

Conditions studied

Complex Regional Pain Syndrome — all drugs for Complex Regional Pain Syndrome →

Sponsor

Millennium Pharmaceuticals, Inc. — full company profile →

Who can join

Adults 18 to 75, any sex, with Complex Regional Pain Syndrome. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Change From Baseline in Mean 24-Hour Pain Intensity as Assessed by NPS Score to the End of Part A Primary · Baseline and Week 15

The 24-hour average pain intensity was calculated from current pain intensity scores collected three times a day as measured by the electronic pain diary daily using NPS. NPS is an 11-point scale, where scores range from 0-10, 0= no pain to 10 = most pain imaginable. Negative change from Baseline indicated improvement.

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-0.74	± 1.614
Double-Blind Treatment Period - Part A: Soticlestat	-1.05	± 1.310

Percent Change From Baseline in Mean 24-Hour Pain Intensity as Assessed by NPS Score to the End of Part A Secondary · Baseline and Week 15

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-12.20	± 29.108
Double-Blind Treatment Period - Part A: Soticlestat	-18.35	± 23.699

Percentage of Participants Considered Responders at the End of Part A Secondary · Week 15

Response was defined as ≥ 30% improvement on the 24-hour pain intensity as assessed by the NPS score. The 24-hour average pain intensity was calculated from current pain intensity scores collected three times a day as measured by the electronic pain diary daily using NPS during Part A. NPS is an 11-point scale, where scores range from 0-10, 0= no pain to 10 = most pain imaginable.

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	22.2
Double-Blind Treatment Period - Part A: Soticlestat	26.7

Change From Baseline in Domain Score of PROMIS-29 Version 2.1 at the End of Part A Secondary · Baseline and Week 15

PROMIS-29 (v2.1) is a health-related quality of life survey assessing 7 domains with 4 questions on a 5-point Likert scale. Total raw domain scores are converted into T-scores from a reference population: Depression: 1=never to 5=always, T-scores:41.0-79.4; Physical function: 1=unable to do to 5=without any difficulty, T-scores: 22.5-57.0; Anxiety: 1=never to 5=always, T-scores: 40.3-81.6; Pain interference: 1=not at all to 5=very much, T-scores: 41.6-75.6; Fatigue: 1=not at all to 5=very much, T-scores: 33.7-75.8; Sleep disturbance: 1=very much to 5=not at all, T-scores: 32.0-73.3; Ability to

Physical Function

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	1.53	± 2.207
Double-Blind Treatment Period - Part A: Soticlestat	2.39	± 4.042

Anxiety

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	3.29	± 10.348
Double-Blind Treatment Period - Part A: Soticlestat	-1.99	± 9.567

Depression

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	1.15	± 10.011
Double-Blind Treatment Period - Part A: Soticlestat	-0.78	± 6.902

Fatigue

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	0.45	± 12.126
Double-Blind Treatment Period - Part A: Soticlestat	-3.66	± 10.456

Sleep Disturbance

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	2.13	± 5.110
Double-Blind Treatment Period - Part A: Soticlestat	2.55	± 1.927

Ability to Participate in Social Roles

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	1.66	± 6.051
Double-Blind Treatment Period - Part A: Soticlestat	2.74	± 5.147

Pain Interference

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-1.53	± 6.257
Double-Blind Treatment Period - Part A: Soticlestat	-0.38	± 7.597

Percent Change From Baseline in Domain Score of PROMIS-29 Version 2.1 at the End of Part A Secondary · Baseline and Week 15

Physical Function

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	4.27	± 6.197
Double-Blind Treatment Period - Part A: Soticlestat	8.00	± 14.106

Anxiety

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	9.35	± 24.153
Double-Blind Treatment Period - Part A: Soticlestat	-2.43	± 16.584

Depression

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	4.51	± 21.864
Double-Blind Treatment Period - Part A: Soticlestat	0.04	± 13.494

Fatigue

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	2.42	± 22.902
Double-Blind Treatment Period - Part A: Soticlestat	-4.62	± 16.045

Sleep Disturbance

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	4.46	± 9.611
Double-Blind Treatment Period - Part A: Soticlestat	4.75	± 3.600

Ability to Participate in Social Roles

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	4.39	± 15.195
Double-Blind Treatment Period - Part A: Soticlestat	7.42	± 13.796

Pain Interference

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-1.88	± 9.149
Double-Blind Treatment Period - Part A: Soticlestat	0.82	± 15.571

Percentage of Participants in Each Category of the Patient Global Impression of Change (PGIC) Scale at the End of Part A Secondary · Week 15

The PGIC is a 7-point Likert scale to address the following question: Since beginning treatment at this clinic would you describe any changes (if any) in activity, limitations, symptoms, emotions and overall quality of life related to your painful condition compared to before treatment? Participants select from scale range of 1-7: very much improved (1); much improved (2); minimally improved (3); no change (4); minimally worse (5); much worse (6); very much worse (7). Only categories with at least 1 participant were reported.

Much Improved

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	33.3
Double-Blind Treatment Period - Part A: Soticlestat	33.3

Minimally Improved

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	11.1
Double-Blind Treatment Period - Part A: Soticlestat	13.3

No Change

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	22.2
Double-Blind Treatment Period - Part A: Soticlestat	33.3

Minimally Worse

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	11.1
Double-Blind Treatment Period - Part A: Soticlestat	0

Missing

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	22.2
Double-Blind Treatment Period - Part A: Soticlestat	20.0

Change From Baseline in Complex Regional Pain Syndrome (CSS) at the End of Part A Secondary · Baseline and Week 15

Signs and symptoms reflecting the sensory, vasomotor, sudomotor/edema, and motor/trophic disturbances of CRPS had been incorporated into a clinically feasible CSS. Total CSS is a 16-point score which was calculated by the number of "yes" answers to the questions on the 8 symptoms and 8 signs when all 16 questions were answered. Negative change from Baseline indicates improvement.

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-2.2	± 2.48
Double-Blind Treatment Period - Part A: Soticlestat	-3.1	± 3.12

Percent Change From Baseline in CSS at the End of Part A Secondary · Baseline and Week 15

Group	Value	95% CI
Double-Blind Treatment Period - Part A: Placebo	-16.1	± 18.89
Double-Blind Treatment Period - Part A: Soticlestat	-23.8	± 26.29

Adverse events — posted to ClinicalTrials.gov

Time frame: From signing of the informed consent up to 15 days after last dose of the study drug (Up to approximately Week 32). Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Double-Blind Treatment Period - Part A: Placebo

Serious: 0/9 (0%)

Deaths: 0/9

Double-Blind Treatment Period - Part A: Soticlestat

Serious: 3/15 (20%)

Deaths: 0/15

Open-Label Extension Period - Part B: Soticlestat

Serious: 0/18 (0%)

Deaths: 0/18

Serious adverse events (2 terms)

Reaction	System	Double-Blind Treatment Per…	Double-Blind Treatment Per…	Open-Label Extension Perio…
Abdominal pain	Gastrointestinal disorders	—	—	—
Cholecystitis	Hepatobiliary disorders	—	—	—

Other adverse events (26 terms — click to expand)

Reaction	System	Double-Blind Treatment Per…	Double-Blind Treatment Per…	Open-Label Extension Perio…
Headache	Nervous system disorders	—	—	—
Dizziness	Nervous system disorders	—	—	—
Nausea	Gastrointestinal disorders	—	—	—
Cough	Respiratory, thoracic and mediastinal disorders	—	—	—
Constipation	Gastrointestinal disorders	—	—	—
Dry mouth	Gastrointestinal disorders	—	—	—
Fatigue	General disorders	—	—	—
Influenza like illness	General disorders	—	—	—
Conjunctivitis	Infections and infestations	—	—	—
Nasopharyngitis	Infections and infestations	—	—	—
Fall	Injury, poisoning and procedural complications	—	—	—
Decreased appetite	Metabolism and nutrition disorders	—	—	—
Arthralgia	Musculoskeletal and connective tissue disorders	—	—	—
Musculoskeletal pain	Musculoskeletal and connective tissue disorders	—	—	—
Depressed mood	Psychiatric disorders	—	—	—
Insomnia	Psychiatric disorders	—	—	—
Suicidal ideation	Psychiatric disorders	—	—	—
Oropharyngeal pain	Respiratory, thoracic and mediastinal disorders	—	—	—
Abdominal pain	Gastrointestinal disorders	—	—	—
Lower respiratory tract infection	Infections and infestations	—	—	—
Oral candidiasis	Infections and infestations	—	—	—
Oral herpes	Infections and infestations	—	—	—
Urinary tract infection	Infections and infestations	—	—	—
Procedural pain	Injury, poisoning and procedural complications	—	—	—
Neck pain	Musculoskeletal and connective tissue disorders	—	—	—
Lethargy	Nervous system disorders	—	—	—

Most-reported serious reactions: Abdominal pain, Cholecystitis.

Data from ClinicalTrials.gov NCT03990649 adverse events section.

Sponsor's own description

The purpose of this study is to investigate the effect of soticlestat (TAK-935) on calculated 24-hour average pain intensity by the numeric pain scale (NPS).

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

Randomized controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in adults with complex regional pain syndrome.
Ratcliffe S, Arkilo D, Asgharnejad M, Bhattacharya S, et al · · 2023 · cited 4× · PMID 36538782 · DOI 10.1093/pm/pnac198

Verify or expand the search:

Other trials of Soticlestat

Trials testing the same drug.

NCT06422377 — A Study Evaluating Soticlestat in Participants With Dravet Syndrome or Lennox-Gastaut Syndrome Who Have Been Exposed to · Phase 3 · terminated
NCT05309902 — A Study of Soticlestat in Healthy Adults To Evaluate the Effect on QTc Interval · Phase 1 · withdrawn
NCT05284760 — A Study of Soticlestat Tablets in Healthy Adults · Phase 1 · completed
NCT05163314 — A Study of Soticlestat as an Add-on Therapy in Children and Adults With Dravet Syndrome or Lennox-Gastaut Syndrome · Phase 3 · terminated
NCT05098041 — A Study of Soticlestat and Rifampin in Healthy Adults · Phase 1 · completed

Other recruiting trials for Complex Regional Pain Syndrome

Currently open trials in the same condition.

NCT06769373 — The Effects of Whirlpool and Contrast Bath in Patients with Complex Regional Pain Syndrome After Distal Radius Fracture · NA · recruiting
NCT06393101 — The Effects and Mechanisms of a High CBD Cannabis Extract (BRC-002) for the Treatment of Pain and Health in Complex Regi · Phase 1 · recruiting

Other Millennium Pharmaceuticals, Inc. trials

Trials by the same sponsor.

NCT03888534 — Intravenous Ixazomib in Pediatric Participants With Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL) or Lymphob · Phase 1 · withdrawn
NCT04056468 — A Study to Evaluate Pharmacokinetics (PK) and Safety of Oral Mobocertinib in Participants With Moderate or Severe Hepati · Phase 1 · completed
NCT04454918 — Study to Assess Absolute Bioavailability (ABA) of TAK-906 and to Characterize Mass Balance, Pharmacokinetics (PK), Metab · Phase 1 · completed
NCT04056455 — A Study of Mobocertinib Capsules in People With Severe Kidney Problems and People With Healthy Kidneys · Phase 1 · completed
NCT04091438 — A Study of a Single Intravenous Infusion Dose of TAK-925 in Participants With Idiopathic Hypersomnia · Phase 1 · completed

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT03990649 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 9 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Millennium Pharmaceuticals, Inc.
Last refreshed: 15 July 2021

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03990649.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing