Characteristics, management and outcome of acquired amegakaryocytic thrombocytopenia

Immune checkpoint inhibitor-related acquired amegakaryocytosis thrombocytopenia: a case report and literature review

Introduction

Immune checkpoint inhibitors (ICIs) are used in several advanced malignancies and may cause various immune-related adverse events (irAEs). Among them, hematological irAEs are less described. Acquired amegakaryocytic thrombocytopenia (AAT) is a rare immune hematologic disorder characterized by severe thrombocytopenia and complete absence of megakaryocytes in bone marrow.

Case presentation

Herein, we present the case of a patient in their 40s with metastatic melanoma who developed an AAT after 12 cycles of nivolumab (anti-PD1). His platelet count decreased by ≤5 × 109/l without other cytopenia. Bone marrow biopsy showed normal cellularity with a complete absence of megakaryocyte and T-CD8+ lymphocyte infiltration. Given the failure of systemic steroids, eltrombopag was started, an oral thrombopoietin receptor agonist (TPO-RA), and his platelet count subsequently increased with complete response.

Discussion

Four other cases are described on literature with the same features than non-ICI-related AAT. All cases occurred after anti-PD/PD-L1 treatment with a median onset of 5 weeks. The presentation of our case is quite different with delayed cytopenia. Both ciclosporin and TPO-RA seem to be efficient therapies.

Conclusion

TPO-RA could be preferred in oncologic patients, but safety data are still missing to define clear guidelines for immune-related AAT management.

Successful avatrombopag combined with cyclosporine treatment for carboplatin/pegylated liposomal doxorubicin/bevacizumab-induced acquired amegakaryocytic thrombocytopenia in a patient with recurrent ovarian cancer: case report

Carboplatin/pegylated liposomal doxorubicin/bevacizumab is an accepted standard anti-cancer treatment option for recurrent ovarian cancer. However, the occurrence of adverse events associated with this therapeutic regimen limits its continued clinical use. Among these adverse events, acquired amegakaryocytic thrombocytopenia is a rare but often potentially life-threatening adverse effect, and is intolerant to multiple treatment approaches. We report, for the first time, the successful treatment using avatrombopag combined with cyclosporine in one case of carboplatin/pegylated liposomal doxorubicin/bevacizumab-induced acquired amegakaryocytic thrombocytopenia, which was refractory or intolerant to glucocorticoids, intravenous immunoglobulin, recombinant human thrombopoietin, androgen, and even thrombopoietin receptor receptor agonist eltrombopag and herombopag. To date, this case manifests as normal platelet counts that are independent of transfusion. Our findings suggest that this combination is a potential and valuable alternative in acquired amegakaryocytic thrombocytopenia.