Ruxolitinib-based regimen in children with primary hemophagocytic lymphohistiocytosis

Haematologica. 2024 Feb 1;109(2):458-465. doi: 10.3324/haematol.2023.283478.

Abstract

Primary hemophagocytic lymphohistiocytosis (pHLH) is a rare immune disorder and hematopoietic stem cell transplan- tation (HSCT) is the only potentially curative treatment. Given the high pre-HSCT mortality of pHLH patients reported in the HLH-2004 study (17%), more regimens to effectively control the disease and form a bridge with HSCT are needed. We conducted a retrospective study of pHLH children treated by ruxolitinib (RUX)-based regimen. Generally, patients received RUX until HSCT or unacceptable toxic side-effect. Methylprednisolone and etoposide were added sequentially when the disease was suboptimally controlled. The primary end point was 1-year overall survival. Twenty-one pHLH patients (12 previously treated and 9 previously untreated) were included with a median follow-up of 1.4 years. At last follow-up, 17 (81.0%) patients were alive with a 1-year overall survival of 90.5% (95% confidence interval: 84.1-96.9). Within the first 8 weeks, all patients had an objective response, of which 19 (90.5%) achieved complete response (CR) and two (9.5%) achieved partial response (PR) as a best response. Seventeen (81.0%) patients received HSCT, of which 13 (76.5%) had CR, three (17.6%) had PR and one (5.9%) had disease reactivation at the time of HSCT. Fifteen (88.2) patients were alive post- HSCT. Notably, eight (38.1%) patients received zero doses of etoposide, suggesting the potential of RUX-based regimen to reduce chemotherapy intensity. Patients tolerated RUX-based regimen well and the most frequently observed adverse events were hematologic adverse events. Overall, RUX-based regimen was effective and safe and could be used as a bridge to HSCT for pHLH children.

MeSH terms

  • Child
  • Etoposide / therapeutic use
  • Hematopoietic Stem Cell Transplantation* / adverse effects
  • Humans
  • Lymphohistiocytosis, Hemophagocytic* / diagnosis
  • Lymphohistiocytosis, Hemophagocytic* / drug therapy
  • Lymphohistiocytosis, Hemophagocytic* / etiology
  • Nitriles*
  • Pathologic Complete Response
  • Pyrazoles*
  • Pyrimidines*
  • Retrospective Studies
  • Treatment Outcome

Substances

  • ruxolitinib
  • Etoposide
  • Nitriles
  • Pyrazoles
  • Pyrimidines

Grants and funding

Funding: This work was supported by Beijing Municipal Science & Tech nology Commission (no. Z221100007422054), the Beijing research Ward Pro ject (no. BCRW202101), the Special Fund of the Pediatric Medical Coordinated Development Center of Beijing Municipal Administration (no. XTZD20180202).