Which melphalan formulation works better against engraftment syndrome?

The incidence of engraftment syndrome (ES), a common complication of autologous haematopoietic cell transplantation (HCT), is comparable between melphalan formulations among patients with multiple myeloma and immunoglobulin light chain amyloidosis, reveals a study.

A group of researchers performed a retrospective, single-centre, observational study and assessed 83 adult multiple myeloma and immunoglobulin light chain amyloidosis patients who received either propylene glycol-containing (PG) or PG-free melphalan 140 mg/m² as single-agent conditioning chemotherapy for autologous HCT from 31 May 2015 to 31 May 2019.

The incidence of ED, the primary outcome, was defined using the Maiolino criteria, with both melphalan formulations. Secondary outcomes included an analysis of potential risk factors for the development of ES and an assessment of overall length of stay (LOS).

The incidence of ES did not differ significantly between PG and PG-free melphalan formulations (35.9 percent vs 27.3 percent; p=0.4). In addition, multivariate logistic regression analysis did not reveal any potential risk factors for ES.

On the other hand, statistically significant difference was found in the number of days to engraftment for PG and PG-free melphalan (15.56 vs 13.82 days, respectively; p=0.01), but this did not translate to a reduction in hospital LOS (19.9 vs 18.59 days; p=0.14).

“Future research is needed to determine whether the faster time to engraftment seen with PG-free melphalan may translate to a decrease in LOS,” the researchers said.