A Study of CNSA-001 in Women With Diabetic Gastroparesis

Phase 2

Completed

Conditions: Gastroparesis

Interventions: Drug: Placebo
Drug: CNSA-001

Registration Number: NCT03712124

Lead Sponsor: PTC Therapeutics

Brief Summary: This study evaluates CNSA-001 (sepiapterin) in the treatment of women with moderate to severe diabetic gastroparesis. Participants will be randomized in a ratio of 1:1 to receive CNSA-001 20 (milligrams) mg/kilogram (kg)/day or placebo. All participants will receive the standard of care for diabetic gastroparesis.

Detailed Description: Nerves throughout the luminal gastrointestinal (GI) tract express neuronal nitric oxide synthase (nNOS), which generates nitric oxide (NO), a key neurotransmitter in the regulation of GI motility. Several co-factors are known to be important for nNOS activity, including nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), calcium, and tetrahydrobiopterin (BH4). The homodimeric conformation of all 3 isoforms of nitric oxide synthase (NOS) is regulated by BH4. In the absence of BH4, uncoupling of NO production occurs and leads to super oxide production, resulting in further impaired nNOS bioactivity.

CNSA-001 is a new chemical entity that is an endogenous, naturally occurring precursor of BH4 via the pterin salvage pathway. Oral administration of CNSA-001 will result in increases in both intracellular and circulating BH4 concentrations. Increased BH4 concentration is hypothesized to improve nNOS function resulting in a positive effect on gastric accommodation and emptying.

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 21

Inclusion Criteria

Informed consent
Diagnosis of diabetes mellitus
Documentation of delayed gastric emptying on gastric emptying scintigraphy or gastric emptying breath test (GEBT) (within 2 year of enrollment)
Symptoms of gastroparesis for at least 6 months with GCSI score >21 indicating moderate to severe symptoms
Gastric accommodation, as measured by nutrient satiety testing, of ≤600 mL
Negative upper endoscopy or upper GI series within 3 years of enrollment (no evidence of mechanical obstruction or peptic ulcer disease)
Either postmenopausal for ≥1 year or surgically sterile (having undergone tubal ligation, hysterectomy, or bilateral oophorectomy) for at least 6 months or, if of childbearing potential and not abstinent, willing to use a highly effective method of contraception throughout the study such as 1 of the following:
- Hormonal contraception (stable dose for 3 months)
- Intrauterine device/Intrauterine Hormone-releasing System
- Barrier contraceptive method (diaphragm, cervical cap, contraceptive sponge, condom)

Participants who are abstinent will not be required to use a contraceptive method unless they become sexually active.

If on analgesics (including narcotics), promotility agents (including metoclopramide), or neuromodulators (including tricyclic antidepressants, gabapentin, and pregabalin), doses are stable for >30 days before randomization and the participant is not expected to require dose changes during the study through the end of treatment (EOT)
Have not used tobacco (for example, cigarettes, e-cigarettes, cigars, smokeless tobacco, nicotine replacement) for 2 weeks prior to Day 1 and willingness to abstain from these products during the study through the EOT

Exclusion Criteria

Male gender
Normal gastric emptying
Gastroparesis from postsurgical etiologies
Another active disorder that could, in the opinion of the investigator, explain symptoms
Weight >100 kg
Alanine aminotransferase > 2× upper limit of normal (ULN)
Pregnant, breastfeeding, or considering pregnancy
Clinically significant cardiac arrhythmia at screening
QT interval corrected for heart rate (QTc) ≥470 milliseconds (msec) using Fridericia's correction (based on triplicate measurements taken at screening)
Resting heart rate ≤40 or ≥110 beats per minute (bpm) or resting blood pressure <90/40 millimeters of mercury (mmHg) or >150/90 mmHg at screening or prior to the first administration of study drug
Recent clinically significant GI bleeding
Taking levodopa or domperidone within 30 days before randomization or expected to require domperidone during the study through the EOT
Taking erythromycin within 30 days before randomization or expected to require erythromycin within 30 days before randomization or expected to require erythromycin during the study; if a participant is taking erythromycin and is otherwise eligible to participate in the study, following informed consent, the participant may go through an erythromycin washout period of 30 days before randomization
Taking any fundic-relaxing agents including, but not limited to, buspirone, clonidine, nitrates, phosphodiesterase inhibitors (that is, sildenafil citrate [Viagra®]) and triptan containing medications, within 30 days before randomization or expected to require any of these agents during the study through the EOT
Taking any systemic antifolates, including, but not limited to, methotrexate, pemetrexed, and trimetrexate or expected to require any systemic antifolates during the study (topical antifolates [for example, cream, ointment, gel] or eye drops with antifolates are allowed)
Pulmonary dysfunction (for example, chronic obstructive pulmonary disease)
Surgery for placement of a gastric stimulator within the past 6 months (participants postoperative >6 months with persistent symptoms and delayed gastric emptying are eligible)
Gastrointestinal disease (such as irritable bowel syndrome, inflammatory bowel disease, chronic gastritis, peptic ulcer disease, small bowel malabsorption) that could affect the absorption of study drug or contraindicate undergoing the GEBT
History of gastric surgery, including Roux-en-Y gastric bypass surgery or an antrectomy with vagotomy, or gastrectomy
History of allergies or adverse reactions to BH4 or related compounds, to any excipients in the study drug formulation, or to egg, wheat, or algae (Spirulina)
Inability to tolerate oral medication
Current participation in any other investigational drug study or use of any investigational agent, investigational device, or approved therapy for investigational use within 30 days or 5 half lives (whichever is longer) before screening
Any clinically significant laboratory abnormality; in general, each laboratory value from screening and baseline chemistry and hematology panels should fall within the limits of the normal laboratory reference range unless deemed not clinically significant by the investigator
Major surgery within the previous 90 days
The participant, in the opinion of the investigator, is unwilling or unable to adhere to the requirements of the study
History of alcohol or drug abuse within 6 months prior to screening or current evidence of substance dependence as determined by the investigator
Episodes of ketoacidosis or hypoglycemia that are frequent as defined by the investigator
History of phenylketonuria (PKU) or hyperphenylalaninemia
Any other conditions, including diabetic comorbidities, that, in the opinion of the investigator or sponsor, would interfere with the participant's ability to participate in the study or increase the risk of participation for that participant

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Participants will receive placebo matching to CNSA-001 BID for 14 days.
CNSA-001	CNSA-001	Participants will receive CNSA-001 20 mg/kg/day (10 mg/kg twice daily \[BID\]) as an oral suspension for 14 days.

Primary Outcome Measures

Name	Time	Method
Change From Baseline (Day 1) in Maximal Tolerated Volume Consumed During the Nutrient Satiety Test at Day 28	Baseline (Day 1), Day 28	Participants consumed 150 mL of Ensure™ every 5 minutes for the nutrient satiety test. At 5-minute intervals, participants scored their fullness using a rating scale that combines verbal descriptors on a scale graded 0 to 5 (0: no symptoms, 1 = first sensation of fullness \[threshold\], 2 = mild, 3 = moderate, 4 = severe and 5 = maximum or unbearable fullness). Participants were told to stop when a score of 5 was obtained. The actual volume of Ensure™ consumed at this point was the maximum tolerated volume.
Change From Baseline (Day 1) in Maximal Tolerated Volume Consumed During the Nutrient Satiety Test at Day 14	Baseline (Day 1), Day 14	Participants consumed 150 milliliters (mL) of Ensure™ every 5 minutes for the nutrient satiety test. At 5-minute intervals, participants scored their fullness using a rating scale that combines verbal descriptors on a scale graded 0 to 5 (0 = no symptoms, 1 = first sensation of fullness \[threshold\], 2 = mild, 3 = moderate, 4 = severe and 5 = maximum or unbearable fullness). Participants were told to stop when a score of 5 was obtained. The actual volume of Ensure™ consumed at this point was the maximum tolerated volume.

Secondary Outcome Measures

Name	Time	Method
Change Form Baseline (Day 1) in the Gastric Emptying Breath Test (GEBT) Excretion Rate at Day 14 and Day 28	Baseline (Day 1), Days 14 and 28	The GEBT is a nonradioactive non-invasive test, conducted over a 4-hour evaluation period and is designed to show how rapidly the stomach empties solids by measuring carbon dioxide (CO2) in a participant's breath. The GEBT measures the rate of CO2 excretion after consumption of a C-enriched test meal. The participant's CO2 excretion rate at any measurement time "t" was calculated and reported using the GEBT metric "kPCD". kPCD stands for "1000 \* Percent Carbon-13 Dose (PCD) excreted per minute." Participants provided baseline (premeal) breath samples and then consumed a standardized 230 kilocalorie (kCal) meal. Single post-meal breath samples were collected in capped glass tubes at 45, 90, 120, 150, 180, and 240 minutes after the meal was consumed. The GEBT kPCD value (13CO2 excretion rate) was proportional to the rate of gastric emptying. Increasing GEBT values represent increasing rates of gastric emptying.
Change From Baseline (Day 1) in the Gastroparesis Cardinal Symptom Index (GCSI) Total Score at Day 14/15 and Day 28	Baseline (Day 1), Days 14/15 and 28	The GCSI consists of 9 symptom severity items covering the following domains (subscales): nausea/vomiting (Questions 1 to 3); post-prandial fullness/early satiety (Questions 4 to 7), and bloating (Questions 8 and 9). Each question was rated on a 6-point Likert scale (0 = None, 1 = Very Mild, 2 = Mild, 3 = Moderate, 4 = Severe and 5 = Very Severe), with lower scores representing lesser symptom severity. To obtain a participant-specific score on each subscale, the scores on each question within the subscale were summed for each participant and divided by the number of questions in the subscale. Total GCSI score was mean of 3 subscales. Total aggregate GCSI score ranges from 0 to 45, with lower scores indicating lesser symptom severity.
Change From Baseline (Day 1) in the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity (PAGI-SYM) Subscale Scores at Day 14 and Day 28	Baseline (Day 1), Days 14 and 28	The PAGI-SYM is a 20-item upper gastrointestinal (GI) symptom severity instrument with 6 subscales: nausea/vomiting (Questions 1 to 3), post-prandial fullness/early satiety (Questions 4 to 7), bloating (Questions 8 and 9), upper abdominal pain (Questions 10 and 11), lower abdominal pain (Questions 12 and 13), and heartburn/regurgitation (Questions 14 to 20). Each question was rated on a 6-point Likert scale (0 = None, 1 = Very Mild, 2 = Mild, 3 = Moderate, 4 = Severe and 5 = Very Severe), with lower scores representing lesser symptom severity. To obtain a participant-specific score on each subscale and the total PAGI-SYM, the scores on each question within the subscale were summed for each participant and divided by the number of questions in the subscale.
Number of Participants With Adverse Events (AEs)	Baseline up to Day 44	An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. Serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. AEs included both SAEs and non-serious AEs. A summary of other non-serious AEs and all SAEs, regardless of causality is located in the 'Reported AE section'.

Trial Locations

Locations (6): GW Research, Inc.
🇺🇸
Chula Vista, California, United States
LMG Research
🇺🇸
Miami, Florida, United States
Johns Hopkins University
🇺🇸
Baltimore, Maryland, United States
Indiana University Hospital
🇺🇸
Indianapolis, Indiana, United States
University of Louisville
🇺🇸
Louisville, Kentucky, United States
Clinical Research Solutions, LLC
🇺🇸
Jackson, Tennessee, United States