Recruiting · registry status

Testing a medicine for constipation

Researchers investigate tenapanor for constipation in conditions involving alpha-synuclein, a protein linked to Parkinson’s.

Testing a treatment or activity · Study reference: NCT06460038

Plain-language introduction written with AI from the registry; not independently checked by a clinician. Read the original details below ↓

This registry record was last updated over six months ago, or its update date is missing. Recruitment may have changed. Confirm with the team before making plans.

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Looking for volunteers

Start (reported actual date): 2025-01-01
Main measurements finished (planned): 2026-12
Study finished (planned): 2027-03

Planned dates can move. A study finishing does not tell us when a paper will be published.

No results summary has been confirmed in the registry records we imported. See connected papers below; we keep checking after recruitment ends.

Changes we have recorded

2026-10-11 — recruiting

These are dates we observed a change, not necessarily the dates it happened.

Papers connected to this study

No connected paper has been found yet. The tracker checks the growing library for study identifiers and registry-linked publications.

Who can join?

Ages 50 years to 89 years · Does not accept healthy volunteers

These are starting points, not the full rules. The research team can tell you whether the study is right for your situation.

Read all the rules for taking part

Sex eligibility reported by registry: all

Inclusion Criteria 1. Age 50-89 years. 2. Diagnosis of PD within Hoehn and Yahr stages 1-3, confirmed by a neurologist per International Parkinson and Movement Disorder Society criteria. 3. Average weekly stool frequency of ≤5 spontaneous bowel movements (SBMs) and ≤2 complete spontaneous bowel movements (CSBMs) over the past 6 months. These criteria will be verified during a 2-week screening period. 4. Stool consistency ≤3 on the Bristol Stool Form Scale (BSFS). This criterion will be verified during a 2-week screening period. 5. Agreement to use contraception, if applicable. Exclusion Criteria 1. Functional diarrhea or IBS-D/M based on Rome IV Criteria. 2. Symptomatic structural GI abnormalities or inflammatory bowel disease. 3. Significant hepatic (ALT or AST ≥ 2.5x the upper limit of normal) or renal (serum creatinine \>2mg/dl) dysfunction. 4. Pregnancy or lactation. 5. Diagnosis of primary dyssynergic defecation by anorectal manometry.

Full study name & original research details

Official study title

Efficacy and Safety of Tenapanor in Synucleinopathy-Related Constipation

Short title used by the registry

Tenapanor in Synucleinopathy-Related Constipation

Original description

Investigation of tenapanor as a potential treatment for synucleinopathy-associated constipation

Further description from the registry

Randomized, double-blind, placebo controlled trial of tenapanor vs. placebo for treating synucleinopathy-associated constipation in Parkinson\'s disease.

Conditions reported: Synucleinopathy; Parkinson's Disease

Registry records for this study

Records are joined using registration identifiers. Titles alone do not establish that two studies are the same.

ClinicalTrials.gov · NCT06460038 ↗ — RECRUITING; checked 2026-10-13

Study type: Interventional
Interventions: Tenapanor; Placebo
Phases: PHASE2
Sponsor: Cedar Valley Digestive Health Center
Start date reported by registry: 2025-01-01 (actual)

Registry updated: 2025-02-10 · Status last verified by the registry submitter: 2025-02

Registry records retrieved 2026-10-13 (UTC). Individual records may have older updates. Recruitment and eligibility must be confirmed with the study team.

Contact the research team

Public study contacts supplied to the registry. Ask whether recruitment is still open and what participation involves.

Richard A. Manfready, MD, AM, FACP · (319) 235-5390 · rman@alum.mit.edu

Harichandana Punukula, PharmD, MS · 319-888-8270 · hpunukula@cvmspc.com

Study locations

Site status can differ from overall study status. “Status not reported” means local availability needs confirmation. Remote participation and travel arrangements must be checked with the team.

Cedar Valley Digestive Health Center

Waterloo, Iowa, United States

Recruiting

Harichandana Punukula, PharmD, MS · 319-888-8275 · hpunukula@cvmspc.com

The original descriptions and participation rules come from the registry. Participation is voluntary and does not guarantee benefit.