Cryopreservation and storage patterns of hematopoietic progenitor stem cells for multiple myeloma.

Autologous hematopoietic stem cell transplantation (HCT) has been a standard of care treatment for eligible patients with newly diagnosed multiple myeloma (MM). Guidelines generally recommend hematopoietic progenitor cell (HPC) harvest for two potential HCT. There is a paucity of data reporting use of such collections in the era of novel approved therapies. In this single-center retrospective study, our goal was to determine the HPC utilization rate and costs associated with leukocytapheresis, collection, storage, and disposal to guide future HPC collection planning. We included 613 patients with MM who underwent HPC collection over a nine-year period. The patients were separated into four groups based on HPC utilization: 1) patients who never proceeded to HCT, or Harvest and Hold (14.8 %), 2) patients who proceeded to one HCT with banked HPC remaining (76.8 %), 3) patients who proceeded to one HCT without HPC remaining (5.1 %), and 4) patients who proceeded to two HCTs (3.3 %). After collection, 73.9 % of patients underwent HCT within 30 days. Of patients with banked HPC, defined as not undergoing HCT within 30 days of leukocytapheresis, the overall utilization rate was 14.9 %. At 2- and 5-years post HPC collection, utilization rate was 10.4 % and 11.5 %, respectively. In conclusion, our results suggest very low utilization of stored HPC, raising into question the current HPC collection targets. Given advances in MM therapy, as well as significant costs associated with harvest and storage, collection for unplanned future use warrants reconsideration. As a result of our analysis, our institution has reduced our HPC collection targets.