---
title: New drug smooths on periods
nct_id: NCT05766813
phase: PHASE2
status: RECRUITING
sponsor: Intra-Cellular Therapies, Inc.
study_type: INTERVENTIONAL
canonical_url: "https://parkinsonspathways.com/trial/NCT05766813"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05766813"
last_fetched: "2026-05-10T14:07:02.716Z"
source: "Parkinson's Pathways (curated)"
---
# New drug smooths on periods

**Goal (in five words):** New drug smooths on periods

**Official Title:** A Randomized, Double-blind, Placebo-controlled Multicenter Study to Assess the Efficacy and Safety of Lenrispodun as Adjunctive Therapy in the Treatment of Patients With Motor Fluctuations Due to Parkinson's Disease

**Trial ID:** [NCT05766813](https://clinicaltrials.gov/study/NCT05766813)

## Key Facts

- **Phase:** PHASE2
- **Status:** RECRUITING
- **Study Type:** INTERVENTIONAL
- **Sponsor:** Intra-Cellular Therapies, Inc.
- **Target Enrollment:** 132 participants
- **Start Date:** 2023-03-13
- **Completion Date:** 2025-09
- **Conditions:** Parkinson Disease
- **Interventions:** Lenrispodun, Placebo
- **Intervention Types:** DRUG

## Summary For Families

The goal is to lessen OFF time and troublesome levodopa-induced dyskinesia so people with Parkinson's have smoother ON periods. Lenrispodun is an experimental PDE1 inhibitor given in addition to your usual levodopa, it boosts intracellular signaling molecules like cAMP and cGMP to enhance and stabilize dopamine-related signaling rather than just increasing levodopa dose. Participants are adults 40 and older with idiopathic PD, Hoehn and Yahr stage 2 or 3 ON, a clear response to levodopa, wearing-off with at least about 2.5 hours OFF time per day on home diaries, and a stable levodopa regimen (minimum about 100 mg three times daily). People with atypical parkinsonism, advanced unpredictable fluctuations, dementia, or certain interacting medications are not eligible.

## Eligibility

- **Minimum age:** 40 Years
- **Sex:** ALL

### Full Criteria

```
Inclusion Criteria:

1. Male or female between 40 years of age and older
2. Body mass index of 19.0-40.0 kg/m2;
3. Diagnosis of PD that is consistent with the UK Parkinson's Disease Society (UKPDS) Brain Bank diagnostic criteria;
4. Hoehn and Yahr Scale stage classification of 2 or 3 when in the ON state;
5. Have a clinically meaningful response to levodopa (levodopa + DDCI combination) based on Investigator assessment, and meet the following:

   1. Have been on a stable and optimal dose of levodopa (levodopa + DDCI combination: minimum dose of levodopa equivalent to 100 mg three times daily) for at least 4 weeks prior to Screening, and are expected to continue the same dose regimen throughout the Double-blind Treatment Period;
   2. If taking other anti-parkinsonian medications (MAO-B \[monoamine oxidase B\] inhibitor, COMT \[catechol-O-methyltransferase\] inhibitor, dopamine agonist) in addition to levodopa, have been on a stable dose for at least 4 weeks prior to Screening and are expected to continue the same dose regimen throughout the Double-blind Treatment Period;

7\. Have wearing-off symptoms and levodopa-induced dyskinesia as per Investigator judgment; 8. Properly complete and return a self-reported home diary for motor function status (Hauser Diary) during the Screening Period, which confirms 3 days (ie, 3 consecutive, 24-hour periods) immediately prior to Baseline, each with at least 2½ hours of OFF time during waking hours.

9\. Has a caregiver to assist with study participation, if determined by the Investigator to be necessary.

Exclusion Criteria:

1. Medical history indicating parkinsonism other than idiopathic PD, including but not limited to, progressive supranuclear gaze palsy, multiple system atrophy, drug-induced parkinsonism, essential tremor, primary dystonia;
2. Has late-stage PD, severe peak-dose dyskinesia, clinically significant end-dose or biphasic dyskinesia, and/or unpredictable or widely swinging fluctuations in their symptoms as assessed by the Investigator;
3. Exhibits clinical signs of dementia as indicated by the Mini-Mental State Examination, 2nd Edition: Standard Version (MMSE-2:SV) score of ≤ 24;
4. Use of moderate or strong CYP3A4 inhibitors within 5 half-lives of Baseline or CYP3A4 inducers within 2 weeks of Baseline;
5. Daily use of nonsteroidal anti-inflammatory drugs (NSAIDs), with the exception of acetylsalicylic acid (ASA);
6. Use of MAO-A inhibitors, phosphodiesterase type 5 (PDE5) inhibitors, or alpha blockers including tamsulosin, within 5 half-lives of Baseline;
```

## Locations (31)

- Clinical Site, Phoenix, Arizona, United States _(33.4484, -112.0740)_
- Clinical Site, Scottsdale, Arizona, United States _(33.5092, -111.8990)_
- Clinical Site, Irvine, California, United States _(33.6695, -117.8231)_
- Clinical Site, Loma Linda, California, United States _(34.0483, -117.2612)_
- Clinical Site, Altamonte Springs, Florida, United States _(28.6611, -81.3656)_
- Clinical Site, Boca Raton, Florida, United States _(26.3587, -80.0831)_
- Clinical Site, Coral Springs, Florida, United States _(26.2712, -80.2706)_
- Clinical Site, Hallandale, Florida, United States _(25.9812, -80.1484)_
- Clinical Site, Maitland, Florida, United States _(28.6278, -81.3631)_
- Clinical Site, Miami, Florida, United States _(25.7743, -80.1937)_
- Clinical Site, Ocala, Florida, United States _(29.1872, -82.1401)_
- Clinical Site, Orlando, Florida, United States _(28.5383, -81.3792)_
- Clinical Site, Orlando, Florida, United States _(28.5383, -81.3792)_
- Clinical Site, Port Orange, Florida, United States _(29.1383, -80.9956)_
- Clinical Site, Tampa, Florida, United States _(27.9475, -82.4584)_
- Clinical Site, Augusta, Georgia, United States _(33.4710, -81.9748)_
- Clinical Site, Decatur, Georgia, United States _(33.7748, -84.2963)_
- Clinical Site, Kansas City, Kansas, United States _(39.1142, -94.6275)_
- Clinical Site, Farmington Hills, Michigan, United States _(42.4853, -83.3772)_
- Clinical Site, Golden Valley, Minnesota, United States _(45.0097, -93.3491)_
- Clinical Site, Albany, New York, United States _(42.6526, -73.7562)_
- Clinical Site, Rock Hill, South Carolina, United States _(34.9249, -81.0251)_
- Clinical Site, Memphis, Tennessee, United States _(35.1495, -90.0490)_
- Clinical Site, Austin, Texas, United States _(30.2672, -97.7431)_
- Clinical Site, Dallas, Texas, United States _(32.7831, -96.8067)_
- Clinical Site, Georgetown, Texas, United States _(30.6327, -97.6772)_
- Clinical Site, Falls Church, Virginia, United States _(38.8823, -77.1711)_
- Clinical Site, Henrico, Virginia, United States _(36.5926, -78.6161)_
- Clinical Site, Kirkland, Washington, United States _(47.6815, -122.2087)_
- Clinical Site, Spokane, Washington, United States _(47.6597, -117.4291)_
- Clinical Site, Milwaukee, Wisconsin, United States _(43.0389, -87.9065)_

## Central Contacts

- ITI Clinical Trials — (CONTACT) — 646-440-9333 — ITCIClinicalTrials@itci-inc.com

---

*Canonical: https://parkinsonspathways.com/trial/NCT05766813*  
*HTML version: https://parkinsonspathways.com/trial/NCT05766813*  
*Source data: https://clinicaltrials.gov/study/NCT05766813*