Second primary malignancy among older adults with multiple myeloma receiving first-line lenalidomide-based therapy: A...

Area of Science:

• Oncology
• Hematology
• Clinical Epidemiology

Background:

• Clinical trials indicate lenalidomide may increase second primary malignancy (SPM) risk in myeloma patients.
• The real-world relevance of this risk, especially in older adults receiving first-line therapy, is not well-established.

Purpose of the Study:

• To evaluate the association between first-line lenalidomide therapy and the risk of SPM in older adults with plasma cell myeloma.
• To determine if lenalidomide-based treatment increases SPM incidence in a real-world setting.

Main Methods:

• Utilized the Surveillance Epidemiology and End Results-Medicare database for adults aged 65+ with myeloma diagnosed between 2007-2015.
• Defined first-line lenalidomide therapy as use within 90 days of diagnosis and SPM as a new malignancy >90 days post-myeloma diagnosis.
• Employed Fine-Gray's competing risks model to compare SPM rates between lenalidomide-treated and non-lenalidomide-treated groups, adjusting for covariates.

Main Results:

• Of 9850 patients, 4009 (41%) received first-line lenalidomide. Over median 5.0 years follow-up, 4.3% developed SPM.
• Cumulative incidence of any SPM at 5 years was similar: 5.3% with first-line lenalidomide vs. 4.4% without (SHR 1.06, P=.53).
• No significant differences in SPM risk were observed for solid tumors or hematologic malignancies between the groups.

Conclusions:

• First-line lenalidomide therapy in older adults with myeloma is not associated with a significantly increased risk of second primary malignancies.
• These real-world findings suggest a favorable safety profile regarding SPM for lenalidomide in this patient population.