A Phase 2 interventional study of IMR-687 and Placebo in Sickle Cell Disease, sponsored by Cardurion Pharmaceuticals, Inc.. Terminated at 49 sites in 13 countries. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-05-15.
Sponsored by Cardurion Pharmaceuticals, Inc. · Phase 2, Interventional, and Treatment
A Study to Evaluate the Safety and Efficacy of IMR-687 in Subjects with Sickle Cell Disease
A phase 2b, randomized, double-blind, placebo-controlled, multicenter study of subjects with sickle cell disease (SCD; homozygous sickle hemoglobin [HbSS], sickle-β0 [HbSβ0] thalassemia, or sickle-β+ [HbSβ+] thalassemia) to evaluate the safety and efficacy of the phosphodiesterase type 9 (PDE9) inhibitor, IMR-687, administered once daily (qd) for 52 weeks.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's enrollment of 115 is above the median of 40 across 769 interventional studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →Cardurion Pharmaceuticals, Inc. is the lead sponsor of 12 studies on the registry; 2 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 4 (50%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Oral administration of once daily IMR-687
Drug: IMR-687
Oral administration of once daily IMR-687
Drug: IMR-687
Oral administration of once daily Placebo
Drug: Placebo
Oral administration of once daily IMR-687
Oral administration of once daily Placebo
Effect on the Incidence of Vaso-occlusive Crises (VOCs)
Annualized rate of VOCs. For each subject, the total number of VOCs on treatment were divided by the time on treatment divided by 52 weeks. The median was then summarized.
Time frame: Baseline to Week 52
Proportion of Patients With Adverse Events and Serious Adverse Events
Incidence of Adverse Events Incidence of Serious Adverse Events
Time frame: Baseline to Week 56
| Milestone | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo |
|---|---|---|---|
| Started | 49 | 34 | 32 |
| Completed | 2 | 6 | 8 |
| Not completed | 47 | 28 | 24 |
Annualized rate of VOCs. For each subject, the total number of VOCs on treatment were divided by the time on treatment divided by 52 weeks. The median was then summarized.
| VOCs/weeks/52 | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo |
|---|---|---|---|
| Effect on the Incidence of Vaso-occlusive Crises (VOCs) | 2.32 (1.02 to 5.51) | 1.20 (0.00 to 3.90) | 2.48 (0.51 to 5.03) |
Incidence of Adverse Events Incidence of Serious Adverse Events
| Participants | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo |
|---|---|---|---|
| Number of participants with Treatment-Emergent Adverse Events | 40 | 29 | 28 |
| Number of participants with Treatment Emergent Serious Adverse Events | 17 | 12 | 12 |
Collected over 56 Weeks. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Higher Dose IMR-687 | 0/47 (0%) | 17/47 (36.2%) | 38/47 (80.9%) |
| Lower Dose IMR-687 | 0/33 (0%) | 12/33 (36.4%) | 29/33 (87.9%) |
| Placebo | 0/32 (0%) | 12/32 (37.5%) | 24/32 (75%) |
| Event | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo |
|---|---|---|---|
| Sickle Cell Anemia with CrisisBlood and lymphatic system disorders | 12/47 | 9/33 | 10/32 |
| AnaemiaBlood and lymphatic system disorders | 3/47 | 4/33 | 0/32 |
| MalariaInfections and infestations | 1/47 | 1/33 | 3/32 |
| SepsisInfections and infestations | 2/47 | 1/33 | 2/32 |
| Abdominal PainGastrointestinal disorders | 0/47 | 1/33 | 0/32 |
| Event | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo |
|---|---|---|---|
| Sickle Cell Anaemia with CrisisBlood and lymphatic system disorders | 12/47 | 9/33 | 10/32 |
| HeadacheNervous system disorders | 12/47 | 9/33 | 7/32 |
| NauseaGastrointestinal disorders | 11/47 | 7/33 | 1/32 |
| DizzinessNervous system disorders | 10/47 | 3/33 | 2/32 |
| VomitingGastrointestinal disorders | 9/47 | 6/33 | 0/32 |
| MalariaInfections and infestations | 6/47 | 2/33 | 4/32 |
Intent to Treat Analysis set
| Age, Continuous(years) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| Mean | 25.0 ± 7.91 | 27.9 ± 8.44 | 26.2 ± 9.27 | 26.2 ± 8.47 |
| Sex: Female, Male(Participants) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| Female | 36 | 14 | 14 | 64 |
| Male | 13 | 20 | 18 | 51 |
| Race (NIH/OMB)(Participants) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 | 0 |
| Black or African American | 34 | 15 | 20 | 69 |
| White | 6 | 10 | 10 | 26 |
| More than one race | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 9 | 9 | 2 | 20 |
| Region of Enrollment(Participants) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| United Kingdom | 3 | 1 | 1 | 5 |
| Ghana | 11 | 2 | 8 | 21 |
| Kenya | 5 | 4 | 4 | 13 |
| Oman | 1 | 4 | 0 | 5 |
| Greece | 0 | 2 | 1 | 3 |
| Lebanon | 0 | 4 | 3 | 7 |
| Morocco | 5 | 2 | 3 | 10 |
| Senegal | 4 | 2 | 1 | 7 |
| Uganda | 16 | 8 | 5 | 29 |
| Tunisia | 1 | 3 | 4 | 8 |
| United States | 3 | 2 | 2 | 7 |
| BMI(kg/m^2) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| Mean | 21.04 ± 3.571 | 21.03 ± 3.451 | 21.10 ± 2.794 | 21.06 ± 3.308 |
| HbF(% of HbF) | Higher Dose IMR-687 | Lower Dose IMR-687 | Placebo | Total |
|---|---|---|---|---|
| Mean | 11.51 ± 7.775 | 10.16 ± 5.453 | 11.16 ± 4.903 | 11.01 ± 6.384 |
PDFs hosted by the registry, ClinicalTrials.gov.
This study is terminated, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Tovinontrine
Cardurion Pharmaceuticals, Inc.