A Study to Assess the Safety and Efficacy of Inclacumab in Participants With Sickle Cell Disease Experiencing Vaso-occlusive Crises

Recruitment Status
COMPLETED - HAS RESULTS
(See Contacts and Locations)Verified October 2025 by Pfizer
Sponsor
Pfizer
Information Provided by (Responsible Party)
Pfizer
Clinicaltrials.gov Identifier
NCT04935879
Other Study ID Numbers:
GBT2104-131
First Submitted
May 25, 2021
First Posted
June 22, 2021
Results First Posted
October 29, 2025
Last Update Posted
December 1, 2025
Last Verified
October 2025

ClinicalTrials.gov processed this data on November 2025Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

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.

Condition or DiseaseIntervention/Treatment
Sickle Cell DiseaseVaso-occlusive Pain Episode in Sickle Cell DiseaseVaso-occlusive Crisis
Drug: InclacumabDrug: Placebo

Study Design

Study TypeInterventional
Actual Enrollment241 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingQuadruple
Primary PurposeTreatment
Official TitleA Randomized, Double-blind, Placebo-controlled, Multicenter Study to Assess the Safety and Efficacy of Inclacumab in Participants With Sickle Cell Disease Experiencing Vaso-occlusive Crises
Study Start DateOctober 3, 2021
Actual Primary Completion DateJune 5, 2024
Actual Study Completion DateJune 5, 2024

Groups and Cohorts

Group/CohortIntervention/Treatment
inclacumab, 30 mg/kg
Participants will receive inclacumab 30 mg/kg administered IV every 12 weeks
Drug: Inclacumab
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
Participants will receive placebo administered IV every 12 weeks.
Drug: Placebo
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

Outcome Measures

Primary Outcome Measures
  1. 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.
Secondary Outcome Measures
  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.

Eligibility Criteria

Ages Eligible for Study(Child, Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
1. 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. 2. Participant is male or female, ≥ 12 years of age at the time of informed consent. 3. 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:
Has no medically determined cause other than a vaso-occlusive event, and
Results in a visit to a medical facility (hospital, emergency department, urgent care center, outpatient clinic, or infusion center) or results in a remote contact with a healthcare provider; and
Requires parenteral narcotic agents, parenteral nonsteroidal anti- inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics. 4. Participants receiving erythropoiesis-stimulating agents (ESA, e.g., erythropoietin \[EPO\]) must be on a stable dose for at least 90 days prior to the Screening Visit and expected to continue with the stabilized regimen throughout the course of the study. 5. Participants receiving hydroxyurea (HU), L-glutamine, or voxelotor (Oxbryta®) must be on a stable dose for at least 30 days prior to the Screening Visit and expected to continue with the stabilized regimen throughout the course of the study.
Exclusion Criteria
1. Participant is receiving regularly scheduled red blood cell (RBC) transfusion therapy (also termed chronic, prophylactic, or preventative transfusion). 2. Participant is taking or has received crizanlizumab (ADAKVEO®) within 90 days prior to the Screening Visit 3. Participant weighs \> 133 kg (292 lbs.). Other protocol-defined Inclusion/Exclusion may apply.

Contacts and Locations

Sponsors and CollaboratorsPfizer
Locations
University of South Alabama Children's and Women's Hospital | Mobile Alabama, United States, 36604University of South Alabama Mitchell Cancer Institute | Mobile Alabama, United States, 36604University of South Alabama Strada Patient Care Center | Mobile Alabama, United States, 36604Arkansas Children's Hospital | Little Rock Arkansas, United States, 72202UC Irvine Health | Orange California, United States, 92868UCI Center for clinical research | Orange California, United States, 92868Uconn Health/Uconn John Dempsey Hospital/Neag Comprehensive Cancer Center/New England Sickle Cell | Farmington Connecticut, United States, 06030Hospital Pharmacy Services- Investigational Drug Services | Chicago Illinois, United States, 60612Rush University Medical Center Investigator Pharmacy | Chicago Illinois, United States, 60612Rush University Medical Center | Chicago Illinois, United States, 60612University of Illinois Clinical Research Center (CRC) | Chicago Illinois, United States, 60612University of Illinois Hospital and Health Sciences System(UI Health) | Chicago Illinois, United States, 60612Dana-Farber Cancer Institute IDS Pharmacy | Boston Massachusetts, United States, 02215Dana-Farber Cancer Institute | Boston Massachusetts, United States, 02215University of Michigan Hospitals - Michigan Medicine | Ann Arbor Michigan, United States, 48109Jacobi Medical Center | The Bronx New York, United States, 10461Duke University Medical Center | Durham North Carolina, United States, 27705DUMC Investigational Drug Services Pharmacy | Durham North Carolina, United States, 27710McGovern Medical School/Health Science Center Houston | Houston Texas, United States, 77030Memorial Hermann - TMC Investigational Drugs, IDS Pharmacy | Houston Texas, United States, 77030Memorial Hermann Hospital, Texas Medical Center - Clinical Research Unit (CRU) | Houston Texas, United States, 77030UT Physicians Comprehensive Sickle Cell Clinic | Houston Texas, United States, 77030Instituto D'Or de Pesquisa e Ensino - Hospital São Rafael | Salvador Estado de Bahia, Brazil, 41253-190Multihemo Serviços Médicos S/A | Recife Pernambuco, Brazil, 50070-460Hospital de Clínicas de Porto Alegre | Porto Alegre Rio Grande do Sul, Brazil, 90035-903Hospital Das Clinicas da Faculdade de Medicina de Ribeirão Preto - USP | Ribeirão Preto São Paulo, Brazil, 14051-140Fundação Faculdade Regional de Medicina de São José do Rio Preto | São José do Rio Preto São Paulo, Brazil, 15090-000Instituto Estadual de Hematologia Arthur Siqueira Cavalcanti - HEMORIO | Rio de Janeiro , Brazil, 20211-030Hospital Samaritano Higienópolis/Esho Empresa De Servicos Hospitalares S.A | São Paulo , Brazil, 01232-010Casa de Saúde Santa Marcelina | São Paulo , Brazil, 08270-070CEPEC-Centro de Pesquisa Clinica | São Paulo , Brazil, 08270-120Clinica de la Costa Ltda. | Barranquilla Atlántico, Colombia, 080020Sociedad de Oncologia y hematologia del Cesar S.A.S. | Valledupar Cesar Department, Colombia, 200001Faculty of Medicine Cairo University | Cairo , Egypt, 11562AinShams University Hospital | Cairo , Egypt, 11588Hôpital Henri Mondor | Créteil , France, 94010Institut Universitaire du Cancer de Toulouse-Oncopole | Toulouse , France, 31059KEMRI/CRDR, Siaya, KEMRI Clinical Research Annex | Kisumu Siaya County, Kenya, 40600International Cancer Institute | Eldoret , Kenya, 30100Gertrude's Children Hospital | Nairobi , Kenya, 00100Kenya Medical Research Institute- Center for Respiratory Disease Research | Nairobi , Kenya, 00100Strathmore University Medical Center - Center for Research in Therapeutic Sciences(CREATES) | Nairobi , Kenya, 00200American University of Beirut Medical Center | Hamra Beirut, Lebanon, Nini Hospital | Tripoli North Lebanon, Lebanon, University of Calabar Teaching Hospital | Calabar Cross River State, Nigeria, 540242National Hospital Abuja | Abuja Federal Capital Territory, Nigeria, 900211University of Abuja Teaching Hospital | Gwagwalada Federal Capital Territory, Nigeria, 902101Ahmadu Bello University Teaching Hospital | Zaria Kaduna State, Nigeria, 1100011University of Nigeria Teaching Hospital | Enugu , Nigeria, 460000Barau Dikko Teaching Hospital/Kaduna State University | Kaduna , Nigeria, 800212Aminu Kano Teaching Hospital | Kano , Nigeria, 700233Department of Pediatrics, College of Medicine, Lagos University Teaching Hospital | Lagos , Nigeria, 100254Sultan َQaboos University Hospital | Muscat , Oman, 123Prince Mohammed bin Nasser Hospital | Jizan Southern, Saudi Arabia, 82943NIMR-Mbeya Medical Research Center | Mbeya , Tanzania, Mersin Universitesi Tip Fakultesi Saglik Arastirma ve Uygulama Merkezi Hastanesi | Yenişehir Mersin, Turkey (Türkiye), 33343Baskent University Hospital | Adana Yuregir, Turkey (Türkiye), 01250Acibadem Adana Hastanesi Cocuk Hematoloji Onkoloji | Adana , Turkey (Türkiye), 01130
Investigators
Study Director: Pfizer CT.gov Call Center, Pfizer
Study Documents (Full Text)
Documents provided by PfizerStudy Protocol  July 13, 2023Documents provided by PfizerStatistical Analysis Plan  June 5, 2025