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The PROLONG Trial - Rituximab Maintenance Therapy in ITP

Prolonging the Response by Low-dose Rituximab Maintenance Therapy in Immune Thrombocytopenia: a Randomized Placebo-controlled Trial - the PROLONG Trial

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03010202
Enrollment
136
Registered
2017-01-04
Start date
2017-01-11
Completion date
2024-12-31
Last updated
2026-09-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Purpura, Thrombocytopenic, Idiopathic

Keywords

immune thrombocytopenia, rituximab, thrombocytopenia

Brief summary

This study is a two phase study that aims to evaluate if low-dose Rituximab maintenance therapy may prolong the the effect of Rituximab in immune thrombocytopenia.

Detailed description

This is a multi-center, international, randomized, two-phase study: First phase (induction phase) is open-label, hypothesis-generating, involving 1:1 randomization into: rituximab (group 1) or rituximab plus dexamethasone (group 2) to determine if the response to rituximab can be improved by the addition of dexamethasone. Second Phase (maintenance phase) is the main part of the study, involving 1:1 double-blind randomization into low dose rituximab or placebo to determine if the response achieved in the first phase can be prolonged by administrating maintenance treatment with low dose rituximab. Primary objective: To determine if maintenance therapy with low-dose rituximab is superior to placebo in prolonging responses among ITP patients who achieved an initial response with rituximab. Secondary objectives: 1. To explore if the initial overall response rate, at week 24, can be improved by at least 10% by adding dexamethasone to rituximab (induction phase). 2. To assess the safety of study treatment, especially infectious episodes (induction & maintenance phases). 3. To assess bleeding complications during the study (induction & maintenance phases). 4. To assess the use of rescue medications and other platelet-elevating therapies during the study (induction & maintenance phases). 5. To determine rate of Complete Response (CR) during induction phase and sustained CR during maintenance phase (induction & maintenance phases). 6. To determine the duration of overall response and CR (induction & maintenance phases). 7. To assess health-related quality of life and fatigue (induction & maintenance phases).

Interventions

DRUGDexamethasone

Comparing the effect of Rituximab infusion With or without Dexamethasone

DRUGRituximab

Comparing maintenance dose of 500mg Rituximab at week 1 and week 24 to Placebo

Sponsors

University Hospital, Akershus
CollaboratorOTHER
Ostfold Hospital Trust
Lead SponsorOTHER
Oslo University Hospital
CollaboratorOTHER
St. Olavs Hospital
CollaboratorOTHER
Helse Stavanger HF
CollaboratorOTHER_GOV
University Hospital of North Norway
CollaboratorOTHER
Haukeland University Hospital
CollaboratorOTHER
Odense University Hospital
CollaboratorOTHER
Centre Hôpital Universitaire Farhat Hached
CollaboratorOTHER
Henri Mondor University Hospital
CollaboratorOTHER
Hospital Militaire Principal d'Instruction de Tunis
CollaboratorUNKNOWN
Centre Hospitalier Universitaire Dijon
CollaboratorOTHER
IUCT Oncopole (Toulouse)
CollaboratorUNKNOWN
Kasr Al-Ainy Hospitals
CollaboratorUNKNOWN
Hôpital Haut-Leveque, Bordeaux, France
CollaboratorUNKNOWN
Hopital La Rabta
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

First randomization (Induction phase): 1. Male or female aged ≥18 years. 2. Diagnosis of primary ITP of less than one year duration having a platelet count of ≤ 30 x109/L measured within 4 weeks prior to inclusion with failure to achieve initial response or relapse either after one cycle of dexamethasone (40 mg daily for 4 days) or 4 weeks with any other steroid (prednisone or prednisolone). Platelet count between 31 to 50 x109/L is accepted if higher platelet count is required due to concomitant antiplatelet therapy or bleeding. 3. Scheduled intravenous treatment of rituximab. 4. Signed and dated written informed consent. 5. Females of child-bearing potential accepting to follow effective contraceptive methods for at least 12 months following the last administration of rituximab or placebo. Inclusion criteria second randomization (maintenance phase): 1. Completion of the induction phase (phase 1) of the study. 2. Sustained response at the end of phase 1. 3. Randomization within 4 weeks after the completion of phase 1, i.e. between week 24 and 28.

Exclusion criteria

first randomization (Induction phase): 1. Previous treatment for ITP with: rituximab, other immune suppressants (including mycophenolate mofetil, aziothioprin, cyclosporine), chemotherapy or splenectomy. 2. Pregnancy or lactation. 3. Known active gastro-duodenal ulcer. 4. Secondary ITP: ITP associated with lymphoma, chronic lymphocytic leukemia, autoimmune disorders such as, common variable immune deficiency, human immunodeficiency virus, or hepatitis C or thrombocytopenia associated with myeloid dysplasia. 5. Concomitant autoimmune hemolytic anemia. 6. History of any major cardiovascular event within the 6 months prior to randomization, including but not limited to: myocardial infarction, unstable angina, cerebrovascular accident, or New York Heart Association Class III or IV heart failure. 7. Active hepatitis B virus or patients with positive HBsAG or HBcAB. 8. Patients with active severe infection, including systemic mycotic infections or a history of recurring or chronic infections or with underlying conditions which may further predispose patients to serious infection. 9. Known allergy and/or sensitivity or contraindication to rituximab or dexamethasone or any of the ingredients. 10. Patients in a severely immune compromised state. 11. Known contraindication to a treatment with any proton-pump inhibitor. 12. Active malignancy or history of malignant disease during the last 2 years except cured skin cancer. 13. Patients with history of poor compliance or history of alcohol/drug abuse or excessive alcohol beverage consumption that would interfere with the ability to comply with the study protocol, or current or past psychiatric disease that might interfere with the ability to comply with the study protocol or give informed consent.

Design outcomes

Primary

MeasureTime frameDescription
Sustained of overall response52 weekssustained overall response during maintenance phase \[loss of overall response is defined as: (1) two consecutive measurements with platelet counts \< 50 x 109/L taken at 1-8-week interval, and/or, (2) use of any ITP-directed therapies, other than study medication, because of bleeding or thrombocytopenia, except for preoperative elevation of platelet count\] (this endpoint applies to maintenance phase only).

Secondary

MeasureTime frameDescription
Improvement at overall response rate in week 24Week 24 (+/- 2 weeks)Overall response during induction phase defined as mean platelet count, determined in week 24 (± 2 weeks) after induction therapy, \> 50 x 10E9/L , without use of any other ITP-directed therapies after week 12 following the first randomization (this endpoint applies to induction phase only).
Safety assessed by the frequency of > grade II adverse events (this endpoint applies to both phases)24 weeks and 52 weeksSafety assessed by the frequency of \> grade II adverse events (this endpoint applies to both phases).
Grade of bleeding during the study (during both phases)24 weeks and 52 weeksGrade of bleeding (this endpoint applies to both phases).
Sustained Complete Response (CR) during maintenance phase52 weeksSustained Complete Response (CR) during maintenance phase defined as platelet count \> 100 x 109/L maintained during maintenance phase, without the use of any ITP-directed therapies
Complete Response during induction phase24 weeks (+/- 2 weeks)Complete Response (CR) during induction phase defined as platelet count, determined in week 24 (± 2 weeks), \> 100 x 109/L without use of any other ITP-directed therapies after week 12 following the first randomization (induction phase)
Rescue medication or other elevating platelet therapyafter 12 weeks in induction phase and 40 weeks in maintenance phaseAdministration of rescue medication or other elevating platelet therapy 1. After week 12 (induction phase) 2. During maintenance phase (maintenance phase).
Health related quality of lifeFirst phase at 24 weeks and second phase at 52 weeksHealth-related quality of life assessed by SF-36 questionnaire (this endpoint applies to both phases).
Platelet count Levels > 50 x 109/L during maintenance phasephase 2 (52 weeks)Percentage of patients with more than 80% of platelet counts level \> 50 x 109/L during the maintenance phase (this endpoint applies to maintenance phase only).

Countries

Norway

Contacts

PRINCIPAL_INVESTIGATORWaleed Ghanima, PhD

Ostfold Hospital Trust

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 10, 2026