Study Evaluates Replacing Prednisone With Dex in Myeloma Regimen

Replacing prednisone with dexamethasone in a regimen comprising cyclophosphamide plus weekly bortezomib appears to be effective for patients with relapsed and refractory multiple myeloma, a study published in Clinical Lymphoma, Myeloma & Leukemia has shown.¹

Cyclophosphamide, bortezomib, and prednisone (CyBorP) is a highly effective regimen with a favorable safety profile in relapsed/refractory multiple myeloma. At Princess Margaret Cancer Centre in Canada, the regimen, which was originally developed to include weekly bortezomib and alternate-day prednisone, was recently modified to include dexamethasone (CyBorD) instead of prednisone. Therefore, researchers sought to evaluate the effectiveness and tolerability of CyBorP and CyBorD in real-world practice.

For the study, researchers retrospectively analyzed data from 96 patients with relapsed/refractory multiple myeloma who received at least 1 28-day treatment cycle. Treatment consisted of cyclophosphamide 300 mg/m² orally on days 1, 8, 15, and 22, plus bortezomib 1.0-1.5 mg/m² IV or SC on days 1, 8, and 15, and prednisone 50 or 100 mg on alternate days or dexamethasone 20 to 40 mg weekly. Most patients also received antiviral prophylaxis with acyclovir 400 mg twice daily.

Results showed that the overall response rate was 69% among the 95 evaluable patients, with 17% achieving a complete response and 26% achieving a very good partial response. Progression-free survival and overall survival for all patients were 16.2 months (95% CI, 7.7-20.1) and 26.3 months (95% CI, 21.6-81.2), respectively.

Researchers also found that was no difference in progression-free or overall survival between patients who were bortezomib-naïve and those who had previously received bortezomib.

In regard to safety, new onset peripheral neuropathy was reported in 17 patients and worsened in 35 patients with pre-existing neurologic symptoms, thus resulting in bortezomib dose reduction and discontinuation in 12% and 6%, respectively. Overall, toxicities with CyBorP and CyBorD were generally mild and manageable.

The findings ultimately suggest that CyBorD/CyBorP is an effective and convenient regimen in the relapsed/refractory treatment setting, including after prior exposure to bortezomib.

Reference

1. Reece DE, Trieu Y, Masih-Khan E, et al. Cyclophosphamide and bortezomib with prednisone or dexamethasone for the treatment of relapsed and refractory multiple myeloma [published online ahead of print May 9, 2016]. Clin Lymphoma Myeloma Leuk. doi: 10.1016/j.clml.2016.04.012.