2009-12-07

The goal of the Minority Medical Student Award Program (MMSAP) is to increase the number of medical students in hematology from under-represented minority groups by introducing them to hematology in their early years of medical school. ASH News Daily is pleased to share a summary of the research conducted by current MMSAP participant Elizabeth Yeboah. Her research mentor was Dr. Christine Chen of the University of Toronto.

As a volunteer at the Medical Day Unit at Toronto General Hospital, Elizabeth became familiar with thalassemia and sickle cell disease. This experience, coupled with her understanding of basic science and the pathobiology of hematologic diseases and her exposure to the clinical manifestations of these diseases, shaped her desire to pursue hematology and apply to the MMSAP. Elizabeth received her undergraduate degree in pathobiology at the University of Toronto, where she is now a second-year medical student.

Background

Lenalidomide is an immunomodulatory agent used for the treatment of relapsed/refractory multiple myeloma (MM). The efficacy of this agent, derived from thalidomide, was shown in two phase III randomized control trials in 2007. Patients taking a combination therapy of lenalidomide and dexamethasone had a longer median time to progression and better overall survival compared to patients on dexamethasone alone. Since these promising pivotal trials, lenalidomide has become commercially available for the treatment of relapsed/refractory MM.

Primary Objectives

Prior to its commercial availability, lenalidomide was provided through an extended access program (EAP). This project examined the single-institution experience of 122 relapsed/refractory MM patients enrolled in the EAP at PrincessMargaret Hospital in Toronto. Patients remained on the EAP until disease progression or adverse events. We hypothesized that a longer duration of therapy would correlate with an improved progression-free survival (PFS) and overall survival (OS). As such, our primary objective was to identify patient demographics, baseline disease characteristics, or treatment details that affected duration of therapy. In the future, these variables could be used by clinicians to identify ideal candidates for lenalidomide therapy who are likely to have prolonged response to treatment.

Methods/Skills Learned

The methodology employed for this study was a retrospective chart review. Therefore, no new technical skills were acquired. However, other important skills I improved upon over the course of the study included the ability to modify the research question and study design to improve the feasibility of the study. I also developed a greater understanding of the international standard used for MM to determine disease progression and response to therapy, which were applied in this study.

Conclusion

Of the 122 MM patients reviewed, 36 percent received ≥12 cycles of lenalidomide, 64 percent received <12 cycles. Comparing these two groups, both the PFS and OS were improved for patients on lenalidomide ≥12 cycles, as hypothesized. A comparison of demographics and disease characteristics between patients on therapy <12 cycles and patients on therapy ≥12 cycles showed that age, gender, MM subtype, and type of prior therapy were similar between the two groups. A comparison of baseline labs between the groups showed that those on therapy ≥12 cycles had significantly higher baseline platelet counts and hemoglobin and significantly lower baseline LDH compared to those on therapy <12 cycles. Dose reductions, mainly due to thrombocytopenia, occurred at an earlier cycle in the patients on therapy <12 cycles. Lastly, more patients on therapy ≥12 cycles achieved a response to therapy. Taken together, these findings suggest that a longer duration of therapy correlated with improved PFS, OS, and response to therapy. Baseline disease characteristics, including platelet count and details of treatment, namely cycle of dose reduction, were factors identified as significantly different between patients on therapy ≥12 cycles and those on therapy <12 cycles.

The MMSAP is sponsored in part by Amgen, Inc., and Genentech BioOncology.

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