Addition of Cyclophosphamide "On Demand" to Lenalidomide and Corticosteroids in Patients With Relapsed/Refractory Multiple Myeloma-A Retrospective Review of a Single-center Experience

Lenalidomide in Multiple Myeloma: Review of Resistance Mechanisms, Current Treatment Strategies and Future Perspectives

Multiple myeloma (MM) is the second most common hematologic malignancy, accounting for approximately 1% of all cancers. Despite the initial poor prognosis for MM patients, their life expectancy has improved significantly with the development of novel agents. Immunomodulatory drugs (IMiDs) are widely used in MM therapy. Their implementation has been a milestone in improving the clinical outcomes of patients. The first molecule belonging to the IMiDs was thalidomide. Subsequently, its novel derivatives, lenalidomide (LEN) and pomalidomide (POM), were implemented. Almost all MM patients are exposed to LEN, which is the most commonly used IMiD. Despite the potent anti-MM activity of LEN, some patients eventually relapse and become LEN-resistant. Drug resistance is one of the greatest challenges of modern oncology and has become the main cause of cancer treatment failures. The number of patients receiving LEN is increasing, hence the problem of LEN resistance has become a great obstacle for hematologists worldwide. In this review, we intended to shed more light on the pathophysiology of LEN resistance in MM, with particular emphasis on the molecular background. Moreover, we have briefly summarized strategies to overcome LEN resistance and we have outlined future directions.

The impact of lenalidomide maintenance on second-line chemotherapy in transplant eligible patients with multiple myeloma

OBJECTIVES

To understand the impact of therapy sequencing on progression-free (PFS) and overall survival (OS) for the treatment of multiple myeloma (MM). The use of daily, low-dose, lenalidomide maintenance (LM) has raised concern for fostering resistance, preventing its use in the relapsed setting.

METHODS

We conducted a retrospective analysis of survival outcomes from the Canadian Myeloma Research Group Database. Patients were grouped based on receipt of LM after autologous stem cell transplant and receipt of lenalidomide in second-line therapy, 575 patients were included.

RESULTS

Patients treated with LM had statistically similar 2nd PFS when re-exposed to lenalidomide in second-line therapy compared to those receiving non-lenalidomide-containing regimens (10.2 vs 14.0 months, P =.53). This cohort also had the longest 2nd OS, 18 months longer than patients treated with LM who did not receive lenalidomide at relapse (55.3 vs 37 months, P =.004). Patients treated with LM also demonstrated deeper responses to second-line therapy than their non-LM counterparts.

CONCLUSION

Our data suggest that patients progressing on LM who receive lenalidomide-containing therapy at first relapse have comparable 2nd PFS and better 2nd OS compared to non-lenalidomide-containing second-line regimens. Identification of patients mostly likely to benefit from further lenalidomide-containing therapy is paramount.

Beyond DNA Damage: Exploring the Immunomodulatory Effects of Cyclophosphamide in Multiple Myeloma

The alkylating agent cyclophosphamide has been used in the treatment of multiple myeloma for over 60 years. At low doses, cyclophosphamide also has significant immunomodulatory activity, which can be used to modify the immunosuppressive tumor microenvironment in order to augment responses to existing therapies. Immune-mediated therapies are becoming more widespread in modern approaches to myeloma treatment. In this review, we discuss the effects cyclophosphamide has on the immune system, and how it can be used synergistically with other treatment modalities including the immunomodulatory agents, monoclonal antibodies and cellular therapies.