Lenalidomide and stem cell collection in patients with multiple myeloma

Abstract

8547 Background: Lenalidomide is an active agent for intial treatment of multiple myeloma. Autologous stem cell transplant (ASCT) as part of first line therapy has been shown to prolong survival. Marrow suppression from lenalidomide may reduce the ability to adequately collect stem cells for ASCT. Recent reports have suggested that (1) the number of CD34+ cells collected is reduced, (2) the number of collections to obtain a target number of cells increased, and (3) the number of failed collections is increased in pts whose initial therapy contained lenalidomide when mobilized with G-CSF alone. We report here our experience with stem cell collection when comparable pts were mobilized primarily with G-CSF and cyclophosphamide (CYT). Methods: Pts were eligible for analysis if they had a diagnosis of myeloma, an initial treatment regimen was documented, and underwent stem cell mobilization and harvest at Penn between 2004 and 2007. Of 158 pts, 21 had a lenalidomide-containing induction regimen. For initial mobilization of these pts, 17 received CYT (16 at 3g/m2, 1 at 4.5 g/m2) and G-CSF 10 ug/kg, 2 received GCSF alone (10 ug/kg) and required salvage G-CSF and AMD3100, and 2 received G-CSF (10 ug/kg) and AMD3100. Results: Adequate numbers of CD34+cells x 10^6/kg (CD34 cells) to proceed with ASCT were collected on all pts in the lenalidomide group (median 6.3, range 2.4–19.7). 2/21 pts required repeat mobilization (both pts who received G-CSF alone) and were mobilized successfully on the second attempt with AMD3100. Median # of collections and CD34 cells and range were: G-CSF/CYT mobilization 3 (1–8) and 6.3 (3.0–19.7); G-CSF alone both failed to collect; G-CSF/AMD mobilization 4.5 (2–6) and 8.4 (5.6–12.3). The median # of cycles of lenalidomide induction therapy was 4 (1–16) and did not influence the # of collections or total CD34 cell counts. We also analyzed 137 pts who received non- lenalidomide containing induction therapy. 2 pts did not collect adequately. Among the remaining 135 pts, 3 pts required repeat mobilization. Median # of collections was 2.0 (1–11) with 7.3 (2.4–72.5) CD34 cellls collected. Conclusions: Initial therapy with lenalidomide does not prevent harvest of adequate numbers of CD34 cells for ASCT, but mobilization with G-CSF alone may be inferior to combination therapy such as G-CSF and CYT. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Celgene