Efficacy of Ruxolitinib with corticosteroids in idiopathic pneumonia syndrome post-allogeneic hematopoietic stem cell transplantation: A single-center experience and systematic review.

Background: Idiopathic Pneumonia Syndrome (IPS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a life-threatening complication with high morbidity and mortality. IPS is thought to arise from damage caused by various inflammatory mediators. This study assesses the effectiveness of Ruxolitinib, a Janus Kinase (JAK) 1 and 2 inhibitor that blocks cytokine production, in combination with corticosteroids (CS) for managing IPS after allo-HSCT, compared to the conventional use of CS alone in a case series and a systematic review of previously published literature.

Methods: The study includes a retrospective case series of three patients treated for IPS with Ruxolitinib and CS from the University of Kansas Medical Center and a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement 2020 guidelines. The systematic review encompassed seven studies involving 346 cases including three cases from the case series. Statistical analyses were conducted using SPSS v.25.

Results: The case series included three patients with IPS after allo-HSCT who received ruxolitinib and CS with favorable results. All patients showed substantial improvement with no IPS-associated mortality. Two of the three patients in the case series were discharged on a 2 L nasal cannula, which was later discontinued during follow-up visits, while the third was discharged on room air. There was marked improvement observed on the computed tomography (CT) following the use of ruxolitinib. Of the total 346 cases included in the systematic review, the median age was 46.6 years (Range 5-72), and 62 % were males. The primary disorders were acute leukemia (52 %), chronic myeloid leukemia (12 %), myelodysplastic syndrome (11 %), Lymphoma (10 %), and others (21 %). Stem cell sources were peripheral blood (45 %), bone marrow (49 %), and cord blood (6 %). Donor types involved match unrelated (55 %), match related (36 %), and mismatched related (4.5 %). Most patients received myeloablative conditioning (81 %). Acute GVHD was observed in 47 %, and chronic GVHD in 38 %. The primary treatment was CS (96 %), with limited use of ruxolitinib (1 %) and etanercept (9.5 %). The mortality rate was 63.3 %, whereas in our case series with the use of ruxolitinib, it was zero.

Conclusion: The combination of Ruxolitinib and CS for treating IPS post-allo-HSCT suggested promising results in the case series, with favorable response and improved survival by blocking the cytokine production contributing to IPS. The significant mortality difference in the systematic review supports the need for innovative treatment approaches, highlighting the potential role of Ruxolitinib in CS-refractory cases. Despite the positive outcomes in the case series, the absence of randomized controlled trials emphasizes the necessity for further research.