CompletedNCT02114203Updated Dec 14, 2017Results posted

Safety, Tolerability, Pharmacokinetics, And Pharmacodynamics Study Of PF-04447943, Co-Administered With And Without Hydroxyurea, In Subjects With Stable Sickle Cell Disease

A Phase 1 interventional study of PDE9i and PDE9i in Phase 1 Sickle Cell, sponsored by Pfizer. Completed at 23 sites in 5 countries. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2017-12-14.

Sponsored by Pfizer · Phase 1, Interventional, and Basic science

Phase: Phase 1
Study type: Interventional
Enrollment: 30
Allocation: Randomized
Ages: 18 Years to 65 Years
Sex: All

Study summary

This study is being conducted to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of an investigational drug, PF-04447943, in subjects with stable sickle cell disease with and without co-administration with hydroxyurea. This study will also aid in selecting the doses for future studies and evaluation of substances in the blood which may help access the effectiveness of the drug.

Conditions studied

Phase 1 Sickle Cell

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Anemia, Sickle Cell 1,103

In context

Anemia, Sickle Cell

1,103 studies on the registry are indexed under Anemia, Sickle Cell; 235 are open to participants now.

This study's enrollment of 30 is below the median of 40 across 750 interventional studies indexed under Anemia, Sickle Cell.

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Lead sponsor

Pfizer is the lead sponsor of 3,244 studies on the registry; 139 are open to participants now.

Of its 582 completed or terminated interventional studies of FDA-regulated products, 381 (65%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years to 65 Years
Sexes eligible: All
Accepts healthy volunteers: No

Inclusion criteria

Male and female subjects with a confirmed diagnosis of sickle cell disease (HbSS or HBS-β0 thalassemia) between the ages of 18 and 65 years, inclusive
Subjects who are being treated with hydroxyurea must be on a stable dose for at least 8 weeks, with the intent of remaining on the same dose of hydroxyurea throughout the clinical trial including the protocol-specified follow-up period. Subjects who are not treated with hydroxyurea should not plan to begin treatment during the study period.
Body Mass Index (BMI) of 17.5 to 35 kg/m2; and a total body weight >40 kg (88 lbs

Exclusion criteria

Exclusion Criteria:

History of a recent major surgery, within 3 months of baseline visit.
Serious infection (requiring hospitalization or parenteral antibiotics) within 1 month of baseline visit.
History of cerebrovascular accident or seizure disorder.
Subjects with a history of clinically significant orthostatic blood pressure (BP) changes or clinically significant orthostatic symptoms.
Known previous diagnosis of acute hepatitis of any aetiology Hepatitis B or C or Human immunodeficiency virus (HIV) infection.
History of any malignancy except for subjects who had a basal or squamous cell cancer which has been treated and fully resolved for a minimum of 5 years.
History or evidence of cardiac disease including: myocardial infarction, cardiac arrhythmia
Systemic therapy with any of the following medications that are strong or moderate CYP3A4 inhibitors within 7 days or 5 half-lives (whichever is longer) or CYP3A inducers within 28 days prior to the first dose of the trial medication, or during the trial.
Use of PDE5 inhibitors within 7 days prior to the first dose of the trial medication, or at any time during the trial.
Creatinine clearance \<30ml/min.
Hemoglobin level \<6 gm/dL.
Alanine transaminase (ALT/SGPT) and Aspartate aminotransferase (AST/SGOT) >2x upper limit of normal, (based on clinic laboratory normal range).
Any condition possibly affecting drug absorption (eg, gastrectomy).
A positive urine drug screen for illicit drug.
History of regular alcohol consumption exceeding 14 drinks/week for females or 21 drinks/week for males (1 drink = 5 ounces (150 mL) of wine or 12 ounces (360 mL) of beer or 1.5 ounces (45 mL) of hard liquor) within 6 months of Screening.
Treatment with an investigational drug within 2 months (or as determined by the local requirement, whichever is longer) or 5 half-lives preceding the first dose of study medication.
12-lead ECG demonstrating QTc >450 or a QRS interval >120 msec msec at Screening.
Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study.
A family history of long QT syndrome and/or ECG abnormalities at screening or randomization, including those listed below:
- Subjects with pre-randomization evidence of QTcF prolongation (defined as >450 ms) at screening or baseline are not eligible for randomization.
- Predominant heart rhythm other than normal sinus rhythm eg, atrial fibrillation, atrial flutter, supraventricular tachycardia.
- Atrioventricular (AV) block greater than first degree.
Use of concomitant medications that prolong the QT/QTc interval
Pregnant females and, breast feeding females and females of childbearing potential; male and female subjects of childbearing potential who are unwilling or unable to use highly effective methods of contraception as outlined in this protocol for the duration of the study and for at least 30 days after the last dose of investigational product.
Subjects who lack the capacity to consent for themselves.

Study design

Phase: Phase 1
Primary purpose: Basic science
Allocation: Randomized
Masking: Triple (Participant, Care provider, Investigator)
Enrollment: 30 participants (actual)

Study arms

Experimental
cohort 1 PF-04447943
Drug: PDE9i
Experimental
cohort 2 PF-04447943
Drug: PDE9i
Placebo comparator
placebo comparator
Drug: placebo for PDE9i
Experimental
optional cohort of PF-04447943
Drug: PDE9i

Interventions

DrugPDE9i
oral dose, every 12 hours for 28 days
DrugPDE9i
oral dose, every 12 hours for 28 days
Drugplacebo for PDE9i
oral dose, every 12 hours for 28 days
DrugPDE9i
oral dose, every 12 hours for 28 days

What researchers measure

Primary outcomes

Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Vital Signs
Number of participants with changes from baseline in vital signs meeting the following criteria is presented: (1) maximum increase from baseline in supine systolic blood pressure (SBP) \>=30 millimeters of mercury (mmHg); (2) maximum increase from baseline in supine diastolic blood pressure (DBP) \>=20 mmHg; (3) maximum decrease from baseline in supine SBP \>=30 mmHg; and (4) maximum decrease from baseline in supine DBP \>=20 mmHg.
Time frame: Baseline up to 30 days post last dose on Day 29
Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Neurologic Function
Clinical assessment of neurologic functions included cranial nerve function, coordination, deep tendon reflexes, muscle strength, and reflexes (left and right ankles). Clinical importance of neurologic function changes was determined by the investigator.
Time frame: Baseline up to Day 29
Number of Participants With Potentially Clinically Important (PCI) Change in Physical Examination Findings
Physical examination included head, ears, eyes, nose, mouth, skin, heart and lung examinations, lymph nodes, gastrointestinal, musculoskeletal, and neurological systems. Clinical importance of physical examination changes was determined by the investigator.
Time frame: Baseline up to 30 days post last dose on Day 29
Number of Participants With Clinically Significant Treatment-Emergent Electrocardiogram (ECG) Findings
Maximum absolute values and increases from baseline were summarized for PR interval (time from the beginning of P wave to the start of QRS complex, corresponding to the end of atrial depolarization and onset of ventricular depolarization), QRS complex (time from Q wave to the end of S wave, corresponding to ventricle depolarization), and QTcF interval (time from the beginning of Q wave to the end of T wave corresponding to electrical systole corrected for heart rate using Fridericia's formula). Number of participants with ECG findings meeting the following criteria is presented: (1) PR interval \>=300 msec; (2) QRS complex \>=200 msec; (3) QTcF interval: 450 to \<480 msec; (4) QTcF interval: 480 to \<500 msec; (5) QTcF interval \>=500 msec; (6) PR interval percent increase from baseline \>=25/50 percent; (7) QRS complex percent increase from baseline \>=25/50 percent; (8) QTcF interval increase from baseline: 30 to \<60 msec; (9) QTcF interval increase from baseline \>=60 msec.
Time frame: Baseline up to 30 days post last dose on Day 29
Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Symptoms of Sickle Cell Disease
The following symptoms were assessed: anemia; fatigue; chronic pain; acute pain; infections; fever; swelling hands; swelling feet; abdominal swelling; pale skin; pale nail beds; yellow tint to skin; whites of eyes turned yellow; stroke. Number of participants with changes from baseline deemed potentially clinically important by the investigator is presented.
Time frame: Baseline up to 30 days post last dose on Day 29
Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product or medical device, regardless of its causal relationship with study treatment. 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; was life-threatening (immediate risk of death); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent AEs are events between first dose of study drug and up to follow-up visit (30 days post last dose on Day 29) that were absent before treatment or that worsened after treatment. AEs included both serious and non-serious AEs.
Time frame: Day 1 to 30 days post last dose on Day 29
Number of Participants With Laboratory Test Abnormalities
The laboratory test included: hematology (hemoglobin, hematocrit, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet count, white blood cell count, absolute total neutrophils, eosinophils, monocytes, basophils, and lymphocytes), chemistry (blood urea nitrogen/urea, serum creatinine, fasting glucose, calcium, sodium, potassium, chloride, total carbon dioxide, aspartate aminotransferase, alanine aminotransferase, total bilirubin, alkaline phosphatase, uric acid, albumin, total protein, and high sensitivity C-reactive protein), urinalysis (pH, qualitative glucose, qualitative protein, qualitative blood, ketones, nitrites, leukocyte esterase, urobilinogen, urine bilirubin, and microscopy), and other tests (follicle stimulating hormone and serum human chorionic gonadotropin, urine drug screening). Abnormality was determined by the investigator.
Time frame: Baseline up to 30 days post last dose on Day 29

Secondary outcomes

Area Under the Curve From Time Zero to 12 Hours Post Dose (AUC(0-12h)) of PF-04447943
AUC(0-12h) referred to area under the plasma concentration-time curve from 0 to 12 hours post dose.
Time frame: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1
Maximum Observed Plasma Concentration (Cmax) of PF-04447943
Time frame: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1
Time for Maximum Observed Plasma Concentration (Tmax) of PF-04447943
Time frame: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1

Results

Posted Dec 14, 2017

Participant flow

Participant flow — Overall Study
Milestone	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Started	7	16	7
Completed	7	14	7
Not completed	0	2	0
Withdrew: Adverse event	0	1	0
Withdrew: Withdrawal by subject	0	1	0

Outcome measures

PrimaryNumber of Participants With Potentially Clinically Important (PCI) Change From Baseline in Vital Signs

Number of participants with changes from baseline in vital signs meeting the following criteria is presented: (1) maximum increase from baseline in supine systolic blood pressure (SBP) \>=30 millimeters of mercury (mmHg); (2) maximum increase from baseline in supine diastolic blood pressure (DBP) \>=20 mmHg; (3) maximum decrease from baseline in supine SBP \>=30 mmHg; and (4) maximum decrease from baseline in supine DBP \>=20 mmHg.

Time frame:: Baseline up to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Vital Signs
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Maximum increase in supine SBP >=30 mmHg	0	0	0
Maximum increase in supine DBP >=20 mmHg	2	0	1
Maximum decrease in supine SBP >=30 mmHg	0	1	0
Maximum decrease in supine DBP >=20 mmHg	2	0	1

PrimaryNumber of Participants With Potentially Clinically Important (PCI) Change From Baseline in Neurologic Function

Clinical assessment of neurologic functions included cranial nerve function, coordination, deep tendon reflexes, muscle strength, and reflexes (left and right ankles). Clinical importance of neurologic function changes was determined by the investigator.

Time frame:: Baseline up to Day 29
Reported as:: Number · participants

Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Neurologic Function
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Neurologic Function	0	0	0

PrimaryNumber of Participants With Potentially Clinically Important (PCI) Change in Physical Examination Findings

Physical examination included head, ears, eyes, nose, mouth, skin, heart and lung examinations, lymph nodes, gastrointestinal, musculoskeletal, and neurological systems. Clinical importance of physical examination changes was determined by the investigator.

Time frame:: Baseline up to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Potentially Clinically Important (PCI) Change in Physical Examination Findings
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Number of Participants With Potentially Clinically Important (PCI) Change in Physical Examination Findings	0	0	0

PrimaryNumber of Participants With Clinically Significant Treatment-Emergent Electrocardiogram (ECG) Findings

Maximum absolute values and increases from baseline were summarized for PR interval (time from the beginning of P wave to the start of QRS complex, corresponding to the end of atrial depolarization and onset of ventricular depolarization), QRS complex (time from Q wave to the end of S wave, corresponding to ventricle depolarization), and QTcF interval (time from the beginning of Q wave to the end of T wave corresponding to electrical systole corrected for heart rate using Fridericia's formula). Number of participants with ECG findings meeting the following criteria is presented: (1) PR interval \>=300 msec; (2) QRS complex \>=200 msec; (3) QTcF interval: 450 to \<480 msec; (4) QTcF interval: 480 to \<500 msec; (5) QTcF interval \>=500 msec; (6) PR interval percent increase from baseline \>=25/50 percent; (7) QRS complex percent increase from baseline \>=25/50 percent; (8) QTcF interval increase from baseline: 30 to \<60 msec; (9) QTcF interval increase from baseline \>=60 msec.

Time frame:: Baseline up to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Clinically Significant Treatment-Emergent Electrocardiogram (ECG) Findings
participants	PF-04447943 25 mg BID	Placebo
Maximum PR interval >=300 msec	0	0
Maximum QRS complex >=200 msec	0	0
Maximum QTcF interval: 450 to <480 msec	3	2
Maximum QTcF interval: 480 to <500 msec	0	1
Maximum QTcF interval: >=500 msec	0	0
PR interval increase >=25/50 percent	0	0
QRS complex increase >=25/50 percent	0	0
QTcF interval increase: 30 to <60 msec	1	0
QTcF interval increase >=60 msec	0	0

PrimaryNumber of Participants With Potentially Clinically Important (PCI) Change From Baseline in Symptoms of Sickle Cell Disease

The following symptoms were assessed: anemia; fatigue; chronic pain; acute pain; infections; fever; swelling hands; swelling feet; abdominal swelling; pale skin; pale nail beds; yellow tint to skin; whites of eyes turned yellow; stroke. Number of participants with changes from baseline deemed potentially clinically important by the investigator is presented.

Time frame:: Baseline up to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Symptoms of Sickle Cell Disease
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Number of Participants With Potentially Clinically Important (PCI) Change From Baseline in Symptoms of Sickle Cell Disease	0	0	0

PrimaryNumber of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)

An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product or medical device, regardless of its causal relationship with study treatment. 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; was life-threatening (immediate risk of death); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent AEs are events between first dose of study drug and up to follow-up visit (30 days post last dose on Day 29) that were absent before treatment or that worsened after treatment. AEs included both serious and non-serious AEs.

Time frame:: Day 1 to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
AEs	7	13	7
SAEs	2	1	0
Withdrawal due to TEAEs	0	1	0

PrimaryNumber of Participants With Laboratory Test Abnormalities

The laboratory test included: hematology (hemoglobin, hematocrit, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet count, white blood cell count, absolute total neutrophils, eosinophils, monocytes, basophils, and lymphocytes), chemistry (blood urea nitrogen/urea, serum creatinine, fasting glucose, calcium, sodium, potassium, chloride, total carbon dioxide, aspartate aminotransferase, alanine aminotransferase, total bilirubin, alkaline phosphatase, uric acid, albumin, total protein, and high sensitivity C-reactive protein), urinalysis (pH, qualitative glucose, qualitative protein, qualitative blood, ketones, nitrites, leukocyte esterase, urobilinogen, urine bilirubin, and microscopy), and other tests (follicle stimulating hormone and serum human chorionic gonadotropin, urine drug screening). Abnormality was determined by the investigator.

Time frame:: Baseline up to 30 days post last dose on Day 29
Reported as:: Number · participants

Number of Participants With Laboratory Test Abnormalities
participants	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Number of Participants With Laboratory Test Abnormalities	7	15	7

SecondaryArea Under the Curve From Time Zero to 12 Hours Post Dose (AUC(0-12h)) of PF-04447943

AUC(0-12h) referred to area under the plasma concentration-time curve from 0 to 12 hours post dose.

Time frame:: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1
Reported as:: Geometric mean · nanogram*hour/milliliter

Area Under the Curve From Time Zero to 12 Hours Post Dose (AUC(0-12h)) of PF-04447943
nanogram*hour/milliliter	PF-04447943 5 mg BID	PF-04447943 25 mg BID
Area Under the Curve From Time Zero to 12 Hours Post Dose (AUC(0-12h)) of PF-04447943	242.0 ± 35	1170 ± 29

SecondaryMaximum Observed Plasma Concentration (Cmax) of PF-04447943

Time frame:: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1
Reported as:: Geometric mean · ng/mL

Maximum Observed Plasma Concentration (Cmax) of PF-04447943
ng/mL	PF-04447943 5 mg BID	PF-04447943 25 mg BID
Maximum Observed Plasma Concentration (Cmax) of PF-04447943	45.83 ± 39	248.2 ± 31

SecondaryTime for Maximum Observed Plasma Concentration (Tmax) of PF-04447943

Time frame:: Prior to 0 hour, and 0.5, 1, 2, 4, 8, and 12 hours post dose on Day 1
Reported as:: Median · hours

Time for Maximum Observed Plasma Concentration (Tmax) of PF-04447943
hours	PF-04447943 5 mg BID	PF-04447943 25 mg BID
Time for Maximum Observed Plasma Concentration (Tmax) of PF-04447943	1.92 (1.00 to 4.00)	1.00 (0.500 to 4.05)

Adverse events

Collected over Day 1 to follow-up visit (30 days post last dose on Day 29). Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
PF-04447943 5 mg BID	—	2/7 (28.6%)	7/7 (100%)
PF-04447943 25 mg BID	—	1/15 (6.7%)	13/15 (86.7%)
Placebo	—	0/7 (0%)	7/7 (100%)

Most frequent serious events

Most frequent serious events
Event	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
Sickle cell anaemia with crisisBlood and lymphatic system disorders	1/7	1/15	0/7
Biliary colicHepatobiliary disorders	1/7	0/15	0/7
PneumoniaInfections and infestations	0/7	1/15	0/7

Most frequent other events

Showing 10 of 53

Most frequent other events
Event	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo
HeadacheNervous system disorders	4/7	5/15	2/7
FatigueGeneral disorders	2/7	6/15	2/7
Abdominal distensionGastrointestinal disorders	1/7	0/15	2/7
Abdominal pain upperGastrointestinal disorders	2/7	0/15	0/7
NauseaGastrointestinal disorders	0/7	1/15	2/7
DizzinessNervous system disorders	0/7	3/15	0/7
Sickle cell anaemia with crisisBlood and lymphatic system disorders	0/7	1/15	1/7
ConstipationGastrointestinal disorders	1/7	0/15	0/7
DyspepsiaGastrointestinal disorders	1/7	0/15	0/7
VomitingGastrointestinal disorders	0/7	0/15	1/7

Baseline characteristics

Baseline analysis population included all participants who were randomized.

Age, Continuous
Age, Continuous(years)	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo	Total
Mean	37.9 ± 10.6	36.3 ± 11.0	39.4 ± 14.0	37.4 ± 11.3

Sex: Female, Male
Sex: Female, Male(Participants)	PF-04447943 5 mg BID	PF-04447943 25 mg BID	Placebo	Total
Female	3	10	5	18
Male	4	6	2	12

Study locations

23 sites

University of Illinois Hospital and Health Sciences System
Chicago, Illinois 60612-5836, United States
University of Illinois at Chicago Clinical Research Center
Chicago, Illinois 60612, United States
University of Illinois Hospital and Health Sciences System
Chicago, Illinois 60612, United States
Boston Medical Center E7E
Boston, Massachusetts 02118, United States
Boston Medical Center
Boston, Massachusetts 02118, United States
Boston University Medical Center
Boston, Massachusetts 02118, United States
Interfaith Medical Center
Brooklyn, New York 11213, United States
Interfaith Medical Center
Brooklyn, New York 11238, United States
UNC Hospitals' Investigational Drug Service Pharmacy
Chapel Hill, North Carolina 27514, United States
UNC School of Medicine Clinical and Translational Research Center
Chapel Hill, North Carolina 27599, United States
Investigational Drug Services
Richmond, Virginia 23298, United States
Virginia Commonwealth University
Richmond, Virginia 23298, United States
Pfizer Clinical Research Unit
Brussels, B-1070, Belgium
Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico
Milano, 20122, Italy
A.O.O.R Villa Sofia - V. Cervello
Palermo, 90146, Italy
Centre for Human Drug Research
Leiden, 2333 CL, Netherlands
Royal Liverpool and Broadgreen University Hospital Trust
Liverpool, Merseyside L7 8XP, United Kingdom
Guy's and St Thomas' NHS Foundation Trust
London, SE1 9RT, United Kingdom
King's College Hospital NHS Foundation Trust
London, SE5 9RS, United Kingdom
Imperial College Healthcare NHS Trust
London, W12 0HS, United Kingdom
Central Manchester University Hospitals NHS Foundation Trust
Manchester, M13 9WL, United Kingdom
Manchester Royal Infirmary
Manchester, M13 9WL, United Kingdom
Oxford University Hospitals NHS Trust
Oxford, OX3 7LE, United Kingdom

References and documents

Publications

Charnigo RJ, Beidler D, Rybin D, Pittman DD, Tan B, Howard J, Michelson AD, Frelinger AL , III, Clarke N. PF-04447943, a Phosphodiesterase 9A Inhibitor, in Stable Sickle Cell Disease Patients: A Phase Ib Randomized, Placebo-Controlled Study. Clin Transl Sci. 2019 Mar;12(2):180-188. doi: 10.1111/cts.12604. Epub 2018 Dec 31. PubMed 30597771 ↗

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Dec 14, 2017, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT02114203
Lead sponsor: Pfizer
Responsible party: Sponsor
First posted: Apr 15, 2014
Start date: Dec 2014
Primary completion: Sep 2016
Completion: Sep 2016
Results posted: Dec 14, 2017
Last update: Dec 14, 2017

Study contacts

Pfizer CT.gov Call Center

study director · Pfizer

Oversight

Data monitoring committee: No

View the source record on ClinicalTrials.gov ↗

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