The following article features coverage from the 2021 Annual Meeting of the Society of Hematologic Oncology (SOHO). Click here to read more of Cancer Therapy Advisor’s conference coverage.

Results of a pooled analysis suggest that melflufen plus dexamethasone is active in patients with relapsed or refractory multiple myeloma (MM) who were exposed to prior alkylators.

The results were presented at the Annual Meeting of the Society of Hematologic Oncology (SOHO) by Paula Rodríguez-Otero, MD, PhD, of Clínica Universidad de Navarra in Pamplona, Spain.

The pooled analysis included data from the O-12-M1 trial (ClinicalTrials.gov Identifier: NCT01897714) and the HORIZON trial (ClinicalTrials.gov Identifier: NCT02963493), both of which were designed to evaluate melflufen plus dexamethasone in relapsed/refractory MM.


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The researchers analyzed data from 202 patients, 157 from the HORIZON trial and 45 from the O-12-M1 trial. In the entire cohort, the overall response rate (ORR) was 30%, the median progression-free survival (PFS) was 4.4 months, and the median overall survival (OS) was 13.6 months.

In all, 186 patients (92%) had been exposed to an alkylator in at least 1 prior line of therapy (LOT), and 33 (16%) were refractory to alkylators in at least 2 prior LOTs.

Patients with fewer prior LOTs in which they were exposed or refractory to alkylators generally had a higher ORR and longer PFS and OS.

Patients not exposed to prior alkylators had an ORR of 56.2%, a median PFS of 7.8 months, and a median OS of 21.1 months. Patients exposed but not refractory to an alkylator in at least 1 prior LOT had an ORR of 34.3%, a median PFS of 5.3 months, and a median OS of 27.2 months.

Patients exposed and refractory to an alkylator in 1 prior LOT had an ORR of 23.3%, a median PFS of 4.6 months, and a median OS of 11.6 months. Patients who were refractory to alkylators in at least 2 prior LOTs had an ORR of 9.1%, a median PFS of 3.1 months, and a median OS of 7.2 months.

The incidence of grade 3-4 treatment-emergent adverse events was similar between patients exposed to prior alkylators (O-12-M1: 83%; HORIZON: 90%) and the overall population (O-12-M1: 84%; HORIZON: 89%).

“Prior alkylator exposure did not adversely impact the efficacy and safety of melflufen therapy in relapsed/refractory multiple myeloma,” Dr Rodríguez-Otero said. “Taken together, these results support the activity of melflufen in heavily pretreated patients with relapsed/refractory multiple myeloma exposed to alkylators in prior lines of therapy.”

Disclosures: This research was supported by Oncopeptides AB. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Read more of Cancer Therapy Advisor’s coverage of SOHO 2021 by visiting the conference page.

Reference

Rodríguez-Otero P, Mateos MV, Oriol A, et al. Melflufen plus dexamethasone in patients with relapsed/refractory multiple myeloma (RRMM) exposed or refractory to prior alkylators: A pooled analysis of the O-12-M1 and HORIZON studies. Paper presented at: Annual Meeting of the Society of Hematologic Oncology (SOHO); September 8-11, 2021.