OBJECTIVES: To synthesize evidence from published literature on disease-specific outcomes in patients with sickle cell disease (SCD) following allogeneic hematopoietic stem cell transplant (HSCT).

METHODS: A systematic literature review was conducted in MEDLINE and Embase to identify English-language publications from interventional and non-interventional studies (up to May 2023) that assessed occurrence of disease-specific outcomes [vaso-occlusive crisis (VOC) and acute chest syndrome (ACS)] in patients with SCD who underwent allogeneic HSCT. Studies that only reported HSCT-related outcomes were excluded. Proportion of patients experiencing VOC or ACS after HSCT were aggregated and descriptively reported.

RESULTS: Twenty-three studies including 2,233 patients met study inclusion criteria. Most studies included pediatric patients (82.6%), employed a myeloablative conditioning regimen (52.0%), and included patients treated with matched-sibling donor (82.6%). Follow-up period for outcome assessment after HSCT varied with a median of 24 months. Engraftment data was reported from 2,209 patients, among whom 85.6% achieved engraftment after HSCT (within-study range: 75%-100%).

Twenty-one of the 23 included studies reported post-HSCT SCD outcomes. VOC was reported in 19 studies (2,155 patients) and ACS was reported in 2 studies (518 patients). Study definitions for VOC varied, including acute pain episode or crisis, recurrent VOC, VOC with liver involvement or stroke and required treatment in a healthcare setting. Aggregated data from studies that reported ≥1 VOC after HSCT showed that 181 (8.4%) of 2,155 patients experienced VOC during follow-up period. Similarly, among studies that reported ≥1 ACS after HSCT, 6 (1.2%) of 518 patients experienced ACS during follow-up period.

CONCLUSIONS: Based on this systematic literature review, a portion of patients with SCD continue to experience VOCs that require care after allogeneic HSCT. Given these limitations with allogeneic HSCT, additional curative treatment approaches are needed for patients with SCD.