Results from a small, retrospective study indicate that combination therapy with Velcade, cyclophosphamide, and dexamethasone may be effective in newly diagnosed myeloma patients with kidney damage.

The findings, discussed in a letter to the editor of the European Journal of Haematology, show that kidney impairment did not worsen in any patients who received the three-drug treatment.

The study investigators also note that side effects were manageable, but recommend further research of the three-drug therapy to determine its safety as a long-term treatment option.

Kidney impairment is a common myeloma-related complication. It is primarily caused by the accumulation in the kidneys of antibody proteins called free light chains. Kidney impairment occurs in nearly 20 percent of newly diagnosed myeloma patients.

The treatment of choice for patients with kidney impairment is Velcade (bortezomib)-based therapy, since Velcade has been shown to be very effective in this patient population. In addition, Velcade is not filtered out through the kidneys and therefore does not further damage them.

However, according to the investigators, patients with kidney damage are frequently excluded from clinical trials of three-drug therapies involving Velcade.

Results of a recent study showed that treatment with Velcade, cyclophosphamide (Cytoxan), and dexamethasone (Decadron), commonly referred to as CyBorD or VCD, is effective and safe in newly diagnosed patients (see related Beacon news).

To assess the efficacy and safety of the combination in patients with kidney impairment, investigators from the Medical University of South Carolina analyzed data from 37 newly diagnosed myeloma patients who were treated with CyBorD from September 2010 to March 2012 at their institution. Of the 37 patients included in the analysis, 38 percent had kidney impairment.

Patients received six-week cycles of CyBorD for up to four cycles. Suitable patients then proceeded to autologous stem transplantation and maintenance therapy with Revlimid.

The median follow-up time was 12.5 months.

The investigators reported that all patients responded well to CyBorD treatment. Overall, 96 percent of patients with normal kidney function and 100 percent of patients with impaired kidney function responded. Patients with normal kidney function had a higher complete response rate (57.1 percent) than patients with kidney impairment (34.8 percent).

After treatment with CyBorD, all patients with kidney impairment had lower free light chain levels in their blood.

Additionally, no patients with kidney impairment required dialysis.

Investigators also measured creatinine clearance (CrCl), a measure of kidney function, in patients with kidney impairment. Low levels of creatinine correspond to reduced kidney function. While median CrCl was 19 mL/min at the time of diagnosis, it increased to 53.5 mL/min after CyBorD treatment.

The median progression-free survival time for all patients was 23 months.

The median overall survival was not yet reached.

According to the investigators, CyBorD had an acceptable safety profile. Ultimately, 16 percent of patients discontinued treatment due to serious side effects. The most common serious side effect was peripheral neuropathy (pain and tingling in the extremities due to nerve damage), which forced 5 percent of patients to discontinue treatment.

For more information, please refer to the study in the European Journal of Haematology (pdf).