A Phase 3 interventional study of Inclacumab and Placebo in Sickle Cell Disease, Vaso-occlusive Pain Episode in Sickle Cell Disease and Vaso-occlusive Crisis, sponsored by Pfizer. Completed at 58 sites in 12 countries. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2025-12-02.
Sponsored by Pfizer · Phase 3, Interventional, and Treatment
This Phase 3 study will assess the safety and efficacy of inclacumab, a P-selectin inhibitor, in reducing the frequency of vaso-occlusive crises (VOCs) in approximately 240 adult and adolescent participants (≥ 12 years of age) with sickle cell disease (SCD). Participants will be randomized to receive inclacumab or placebo.
Eligible participants will be administered inclacumab or placebo intravenous (IV) every 12 weeks.
The total duration of treatment for each participant will be 48 weeks.
Participants that complete the study through Week 48 will be provided the opportunity to enroll in an open-label extension (OLE) study.
104 studies on the registry are indexed under Vaso-Occlusive Crises; 31 are open to participants now.
This study's enrollment of 241 is above the median of 81 across 86 interventional studies indexed under Vaso-Occlusive Crises.
Browse Vaso-Occlusive Crises studies →Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Compared within Vaso-Occlusive Crises, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Anemia, Sickle Cell. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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.
Participant has a confirmed diagnosis of SCD (HbSS, HbSC, HbSB0 thalassemia, or HbSB+ thalassemia genotype).
Documentation of SCD genotype is required and may be based on documented history of laboratory testing or confirmed by laboratory testing during Screening.
Participant has experienced between 2 and 10 VOCs within the 12 months prior to the Screening Visit as determined by documented medical history. A prior VOC is defined as an acute episode of pain which:
Exclusion Criteria:
Other protocol-defined Inclusion/Exclusion may apply.
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.
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.
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.
Participants will receive inclacumab 30 mg/kg administered IV every 12 weeks
Drug: Inclacumab
Participants will receive placebo administered IV every 12 weeks.
Drug: Placebo
Inclacumab will be supplied in single use 10 mL vials at a concentration of 50 mg/mL. One vial contains 500 mg of inclacumab. This is a liquid concentrate for IV infusion.
Placebo will be supplied in single use 10 mL vials containing the same ingredients without the active drug. Placebo will be prepared as a liquid concentrate for IV infusion and administered in the same manner as active study drug
Rate of Vaso-occlusive Crises (VOCs) [Adjudicated] Through Week 48
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral nonsteroidal anti-inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics. The rate of VOC was defined as number of VOC events per 48 weeks and presented in this outcome measure.
Time frame: Randomization (Day 1) up to Week 48
Time to First VOC Through Week 48
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Time to first VOC was the time between randomization date and onset date of first VOC event during 48 weeks. Kaplan-Meier method was used for estimation.
Time frame: Randomization (Day 1) up to Week 48
Time to Second VOC Through Week 48
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Time to second VOC was the time between randomization date and onset date of second VOC event during 48 weeks. Kaplan-Meier method was used for estimation.
Time frame: Randomization (Day 1) up to Week 48
Percentage of Participants With no VOCs Through Week 48
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Participants without an observed VOC who discontinued the study prior to the end of the 48-week treatment period were assumed to had experienced at least one VOC.
Time frame: Randomization (Day 1) up to Week 48
Rate of VOCs Required Admission to a Healthcare Facility and Treatment With Parenteral Pain Medication [Adjudicated] Through Week 48
A VOC that required admission to a healthcare facility and treatment with parenteral pain medication where admission included: a hospital admission or an admission to an emergency room, observation unit, or infusion center for \>= 12 hours, or 2 visits to an emergency room, observation unit, or infusion center over a 72-hour period. The rate of VOC was defined as number of VOC events per 48 weeks; rate of VOCs which required admission to a healthcare facility and treatment with parenteral pain medication is presented in this outcome measure.
Time frame: Randomization (Day 1) up to Week 48
Rate of Inpatient Hospitalization Days for a VOC Through Week 48
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility hospitalization. For each VOC event requiring inpatient hospitalization (regardless of treatment received) during the 48-week, the number of days hospitalized were determined based on the hospital admission and discharge dates. The rate of inpatient hospitalization days was defined as number of inpatient hospitalization days for a VOC per 48 weeks and presented in this outcome measure.
Time frame: Randomization (Day 1) up to Week 48
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product during the course of a clinical investigation. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of an investigational product, whether or not thought to be related to the investigational product. A TEAE was defined as an AE with an onset after the initiation of dosing for the first dose of study drug. A serious adverse events (SAE) or serious suspected adverse reaction is an AE or suspected adverse reaction that, at any dose, in the view of the either the investigator or sponsor, results in any of the following outcomes: death, life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization and congenital anomaly/birth defect. AEs included both serious and all non-SAEs.
Time frame: Day 1 up to Week 60 (12 week of follow-up post Week 48)
| Milestone | Inclacumab | Placebo |
|---|---|---|
| Started | 119 | 122 |
| Treated | 118 | 121 |
| Completed | 103 | 108 |
| Not completed | 16 | 14 |
| Withdrew: Adverse event | 2 | 1 |
| Withdrew: Lost to follow-up | 1 | 1 |
| Withdrew: Pregnancy | 2 | 3 |
| Withdrew: Withdrawal by subject | 8 | 6 |
| Withdrew: Other | 3 | 3 |
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral nonsteroidal anti-inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics. The rate of VOC was defined as number of VOC events per 48 weeks and presented in this outcome measure.
| Events per 48 weeks | Inclacumab | Placebo |
|---|---|---|
| Rate of Vaso-occlusive Crises (VOCs) [Adjudicated] Through Week 48 | 1.49 (1.22 to 1.83) | 1.58 (1.30 to 1.93) |
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Time to first VOC was the time between randomization date and onset date of first VOC event during 48 weeks. Kaplan-Meier method was used for estimation.
| Weeks | Inclacumab | Placebo |
|---|---|---|
| Time to First VOC Through Week 48 | 28.7 (15.7 to 43.1) | 21.6 (17.3 to 28.7) |
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Time to second VOC was the time between randomization date and onset date of second VOC event during 48 weeks. Kaplan-Meier method was used for estimation.
| Weeks | Inclacumab | Placebo |
|---|---|---|
| Time to Second VOC Through Week 48 | NA (NA to NA) | NA (NA to NA) |
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), or resulted in a remote contact with a healthcare provider and required parenteral narcotic agents, parenteral NSAIDs, or an increase in treatment with oral narcotics. Participants without an observed VOC who discontinued the study prior to the end of the 48-week treatment period were assumed to had experienced at least one VOC.
| Percentage of participants | Inclacumab | Placebo |
|---|---|---|
| Percentage of Participants With no VOCs Through Week 48 | 36.0 (27.1 to 45.0) | 25.7 (17.7 to 33.7) |
A VOC that required admission to a healthcare facility and treatment with parenteral pain medication where admission included: a hospital admission or an admission to an emergency room, observation unit, or infusion center for \>= 12 hours, or 2 visits to an emergency room, observation unit, or infusion center over a 72-hour period. The rate of VOC was defined as number of VOC events per 48 weeks; rate of VOCs which required admission to a healthcare facility and treatment with parenteral pain medication is presented in this outcome measure.
| Events per 48 weeks | Inclacumab | Placebo |
|---|---|---|
| Rate of VOCs Required Admission to a Healthcare Facility and Treatment With Parenteral Pain Medication [Adjudicated] Through Week 48 | 0.85 (0.65 to 1.10) | 0.83 (0.64 to 1.08) |
A VOC was defined as an acute episode of pain that: had no medically determined cause other than a vaso-occlusive event; resulted in a visit to a medical facility hospitalization. For each VOC event requiring inpatient hospitalization (regardless of treatment received) during the 48-week, the number of days hospitalized were determined based on the hospital admission and discharge dates. The rate of inpatient hospitalization days was defined as number of inpatient hospitalization days for a VOC per 48 weeks and presented in this outcome measure.
| Hospitalization days per 48 weeks | Inclacumab | Placebo |
|---|---|---|
| Rate of Inpatient Hospitalization Days for a VOC Through Week 48 | 4.96 (3.05 to 8.07) | 5.37 (3.34 to 8.62) |
An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product during the course of a clinical investigation. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of an investigational product, whether or not thought to be related to the investigational product. A TEAE was defined as an AE with an onset after the initiation of dosing for the first dose of study drug. A serious adverse events (SAE) or serious suspected adverse reaction is an AE or suspected adverse reaction that, at any dose, in the view of the either the investigator or sponsor, results in any of the following outcomes: death, life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization and congenital anomaly/birth defect. AEs included both serious and all non-SAEs.
| Participants | Inclacumab | Placebo |
|---|---|---|
| Number of Participants With Treatment Emergent Adverse Events (TEAEs) | 87 (3.05 to 8.07) | 97 (3.34 to 8.62) |
Collected over Day 1 up to Week 60 (12 week of follow-up post Week 48). Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Inclacumab | 3/118 (2.5%) | 23/118 (19.5%) | 83/118 (70.3%) |
| Placebo | 2/121 (1.7%) | 27/121 (22.3%) | 90/121 (74.4%) |
| Event | Inclacumab | Placebo |
|---|---|---|
| AnaemiaBlood and lymphatic system disorders | 3/118 | 8/121 |
| MalariaInfections and infestations | 5/118 | 7/121 |
| PneumoniaInfections and infestations | 5/118 | 5/121 |
| Bacterial infectionInfections and infestations | 2/118 | 3/121 |
| Urinary tract infectionInfections and infestations | 2/118 | 1/121 |
| Pulmonary embolismRespiratory, thoracic and mediastinal disorders | 2/118 | 0/121 |
| HaemolysisBlood and lymphatic system disorders | 1/118 | 1/121 |
| Haemolytic anaemiaBlood and lymphatic system disorders | 1/118 | 0/121 |
| Iron deficiency anaemiaBlood and lymphatic system disorders | 1/118 | 0/121 |
| Sickle cell anaemia with crisisBlood and lymphatic system disorders | 1/118 | 0/121 |
| Event | Inclacumab | Placebo |
|---|---|---|
| MalariaInfections and infestations | 18/118 | 24/121 |
| Sickle cell anaemia with crisisBlood and lymphatic system disorders | 21/118 | 21/121 |
| HeadacheNervous system disorders | 16/118 | 21/121 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 15/118 | 12/121 |
| Back painMusculoskeletal and connective tissue disorders | 10/118 | 14/121 |
| Upper respiratory tract infectionInfections and infestations | 9/118 | 12/121 |
| NasopharyngitisInfections and infestations | 9/118 | 2/121 |
| AnaemiaBlood and lymphatic system disorders | 5/118 | 9/121 |
| Bacterial infectionInfections and infestations | 0/118 | 8/121 |
| NauseaGastrointestinal disorders | 7/118 | 1/121 |
The intent-to-treat (ITT) population included all randomized participants.
| Age, Continuous(Years) | Inclacumab | Placebo | Total |
|---|---|---|---|
| Mean | 25.0 ± 7.14 | 24.6 ± 8.34 | 24.8 ± 7.76 |
| Sex: Female, Male(Participants) | Inclacumab | Placebo | Total |
|---|---|---|---|
| Female | 64 | 63 | 127 |
| Male | 55 | 59 | 114 |
| Ethnicity (NIH/OMB)(Participants) | Inclacumab | Placebo | Total |
|---|---|---|---|
| Hispanic or Latino | 18 | 19 | 37 |
| Not Hispanic or Latino | 92 | 102 | 194 |
| Unknown or Not Reported | 9 | 1 | 10 |
| Race/Ethnicity, Customized(Participants) | Inclacumab | Placebo | Total |
|---|---|---|---|
| Race — African | 63 | 58 | 121 |
| Race — American Indian or Alaska Native | 3 | 2 | 5 |
| Race — Arab | 1 | 2 | 3 |
| Race — Black or African American | 16 | 24 | 40 |
| Race — Middle Eastern | 1 | 0 | 1 |
| Race — Other | 2 | 1 | 3 |
| Race — Multiracial | 22 | 25 | 47 |
| Race — Not Reported | 4 | 0 | 4 |
| Race — White | 7 | 10 | 17 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
Data sharing details ↗ · www.pfizer.com
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Studies of the drug tested here: Inclacumab