Second-Line Therapy for Immune Thrombocytopenia: Real-World Experience in Canada

Main Article Content

Hasmik Nazaryan
Yang Liu
Emily Sirotich
Joanne Duncan
Ishac Nazy
Donald Arnold

Abstract

Background
The sequence of second-line therapy used for the treatment of immune thrombocytopenia (ITP) is variable. This study aimed to describe the types and sequences of second-line therapies for a large cohort of ITP patients in Canada.


Methods
We completed a retrospective cohort study of the McMaster ITP Registry. We included patients with primary or secondary ITP who had received one or more second-line therapies including any of the splenectomy, rituximab, danazol, dapsone, or thrombopoietin receptor agonists (TPO-RAs), or immunosuppressant medications. Immunosuppressant medications included azathioprine, cyclophosphamide, cyclosporine, or mycophenolate given alone or in combination.


Results
We identified 204 ITP patients who had received one or more second-line therapies. The most common second-line therapies were immunosuppressant medications (n = 106; 52.0%), splenectomy (n = 106; 52.0%), TPO-RAs (n = 75; 36.8%), danazol (n = 73; 35.8%), and rituximab (n = 67; 32.8%). For patients who received only one second-line therapy (n = 88), the most common treatment was splenectomy (n = 28; 31.8%). For patients who received more than one second-line therapy (n = 116), the most common treatment sequence was splenectomy, followed by immunosuppressant medications (n = 7; 6.0%). Of the 154 evaluable patients at the end of follow-up, 69 (44.8%) achieved a complete platelet count response and 101 (65.5%) achieved a partial response.


Conclusion
Immunosuppressant medications and splenectomy are commonly used as second-line therapies for ITP in Canada. Treatment choices and the sequence of treatments were variable.


RESUME
Contexte
La séquence de la thérapie de deuxième ligne utilisée pour le traitement de la thrombocytopénie immunitaire (PTI) est variable. Cette étude visait à décrire les types et les séquences des thérapies de deuxième ligne pour une large cohorte de patients atteints de PTI au Canada.


Méthodes
Nous avons réalisé une étude de cohorte rétrospective du registre ITP de McMaster. Nous avons inclus des patients atteints de PTI primaire ou secondaire qui avaient reçu une ou plusieurs thérapies de deuxième ligne, y compris une splénectomie, du rituximab, du danazol, de la dapsone ou des agonistes des récepteurs de la thrombopoïétine (AR-TPO), ou des médicaments immunosuppresseurs. Les médicaments immunosuppresseurs comprennent l’azathioprine, le cyclophosphamide, la cyclosporine ou le mycophénolate, administrés seuls ou en combinaison.


Résultats
Nous avons identifié 204 patients atteints de PTI qui avaient reçu une ou plusieurs thérapies de seconde ligne. Les thérapies de deuxième ligne les plus courantes étaient les immunosuppresseurs (n = 106; 52.0%), la splénectomie (n = 106; 52.0%), les AR-TPO (n = 75; 36.8%), le danazol (n = 73; 35.8%) et le rituximab (n = 67; 32.8%). Pour les patients qui n’ont reçu qu’un seul traitement de deuxième intention (n = 88), le traitement le plus courant était la splénectomie (n = 28; 31.8%). Pour les patients qui ont reçu plus d’un traitement de deuxième ligne (n = 116), la séquence de traitement la plus courante était la splénectomie, suivie par les médicaments immunosuppresseurs (n = 7; 6.0%). Sur les 154 patients évaluables à la fin du suivi, 69 (44.8%) ont obtenu une réponse complète de la numération plaquettaire et 101 (65.5%) une réponse partielle.


Conclusion
Les médicaments immunosuppresseurs et la splénectomie sont couramment utilisés comme traitements de deuxième intention pour le PTI au Canada. Les choix de traitement et la séquence des traitements sont variables.

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