Work

Oral versus intravenous melphalan for autologous stem cell transplantation conditioning in lymphoma and multiple myeloma: a retrospective cohort study

Year: 2026

Type: article

Abstract: Objective To compare oral (PO) and intravenous (IV) melphalan as conditioning regimens for autologous stem cell transplantation in patients with lymphoma or multiple myeloma (MM). Methods A retrospective propensity score-matched cohort analysis of 106 patients (76 with lymphoma and 30 with MM) was conducted to compare engraftment outcomes, adverse events, and survival between PO and IV melphalan conditioning. The primary endpoint was 3-year progression-free survival. Results The BEAM (carmustine, etoposide, cytarabine, and melphalan) regimen is the standard conditioning regimen for lymphoma and a single-agent melphalan was administered for MM. In patients with lymphoma, IV melphalan was associated with faster neutrophil engraftment than PO melphalan (10 vs 12 days, p = 0.025). In MM, IV melphalan was associated with faster platelet (PLT) engraftment (11 vs 14 days, p = 0.021). The PO group had higher grade 3–4 anemia (37.74% vs 18.87%, p = 0.031) but lower febrile neutropenia (35.85% vs 56.60%, p = 0.032) and mucositis (7.55% vs 33.96%, p = 0.001). In the PO group, grade 3–4 anemia correlated with delayed PLT engraftment (62.5% vs 21.4%, p = 0.008). Compared with IV melphalan, divided-dose oral melphalan was associated with lower rates of diarrhea (18.87% vs 37.74%) and oral mucositis (7.55% vs 33.96%), with an overall gastrointestinal toxicity rate (defined as at least one gastrointestinal adverse event) of 21.7% in the PO group versus 56.60% in the IV group. Complete response rates and 3-year survival outcomes were comparable between the groups. Conclusion Oral melphalan is a pragmatic alternative when IV melphalan is unavailable, with comparable efficacy and a distinct toxicity profile. Given variable bioavailability, it should not be considered bioequivalent to IV melphalan. Prospective pharmacokinetic studies are warranted to validate these findings.

Source: Frontiers in Oncology

DOI: 10.3389/fonc.2026.1923679