# Bortezomib, Mitoxantrone Hydrochloride Liposome, and Dexamethasone for Relapsed/Refractory Multiple Myeloma: A Multi‐Center, Open‐Label Phase I Trial

## TL;DR

A new treatment combining bortezomib, liposomal mitoxantrone, and dexamethasone shows promise for treating multiple myeloma that has returned or stopped responding to other treatments.

## Contribution

This is the first phase I trial evaluating the safety and efficacy of the VMitD triplet regimen for relapsed/refractory multiple myeloma.

## Key findings

- The regimen achieved an overall response rate of 86.7% in 15 evaluable patients.
- The most common severe non-hematologic adverse event was pneumonia (20%).
- Thrombocytopenia was the most frequent grade 3/4 hematologic toxicity (70%).

## Abstract

Mitoxantrone hydrochloride liposome (Lipo‐MIT) has shown clinical benefits in various tumors. However, there is no prospective study evaluating its effectiveness and safety in relapsed/refractory multiple myeloma (RRMM). A phase I trial of bortezomib, Lipo‐MIT, and dexamethasone (VMitD) with the primary endpoints being safety and efficacy was performed.

Twenty subjects were enrolled this study, and the dose of Lipo‐MIT was designed to be 12, 16, and 20 mg/m2 at Day 1 combined with bortezomib and dexamethasone.

The most common grade 3/4 non‐hematologic adverse event was pneumonia (20%). The most frequently observed grade 3/4 hematologic toxicity included thrombocytopenia (70%), neutropenia (55%), lymphopenia (30%), and anemia (10%). Fifteen subjects received at least one efficacy evaluation, including 60% (9/15) with a very good partial response (VGPR) or better, resulting in an overall response rate (ORR) of 86.7% (13/15).

This is the first report about the novel triplet regimen VMitD, including Lipo‐MIT for RRMM, which was well tolerated and demonstrated efficacy. Further studies are required to assess the outcomes more accurately and to evaluate its effectiveness in comparison to other salvage regimens containing proteasome inhibitors and anthracyclines.

Trial Registration: ClinicalTrials.gov identifier: NCT05052970