Multiple myeloma patients receiving an infusion of their own stem cells either one day or two days after undergoing treatment with high-dose melphalan demonstrate similar clinical outcomes, according to a recent U.S. study.

The study investigators conclude that a day of rest between treatment with melphalan and stem cell infusion appears not to be necessary.  Based on their findings, they recommend that melphalan administration the day before stem cell infusion should be considered as standard of care.

According to Dr. Giampaolo Talamo of the Penn State Hershey Cancer Institute in Hershey, Pennsylvania, and lead investigator of the study, the two most important benefits of giving melphalan as a single dose on the day prior to transplantation are decreased costs and simplification of the treatment process.

“It simplifies the process for patients, doctors, and nurses. Less material like intravenous lines and bags, and less time and supervision spent for the administration of chemotherapy,” said Dr. Talamo.  “Besides cutting the cost of material and personnel, it cuts the cost of the transplant because it requires a day less in the hospital.”

An autologous stem cell transplant is a procedure in which stem cells are harvested from a patient prior to high-dose chemotherapy and later re-infused into the patient’s body to replace the cells that were destroyed by chemotherapy. This procedure is a standard course of treatment for multiple myeloma patients aged 65 years and under.

Melphalan ^[1] (Alkeran) is the chemotherapeutic agent generally used with stem cell transplants for myeloma patients. According to the study investigators, many treatment centers typically wait at least 24 hours between melphalan administration and stem cell infusion, believing a “day of rest” in between may be necessary to avoid any possible negative effects of chemotherapy on the re-infused stem cells.

The study investigators point out, however, that the “schedules of administration are based more often on empiric policies than scientific rationale or data.”

This lack of data led researchers from the Penn State Hershey Cancer Institute and the University of Utah to evaluate whether the timing between treatment with melphalan and an autologous stem cell transplant would have an impact on clinical outcomes.

The study investigators retrospectively analyzed data from 138 myeloma patients treated at the Penn State Hershey Cancer Institute who received high-dose melphalan followed by an autologous stem cell transplant between 2007 and 2010. The median age of the patients was 59 years.

From 2007 to 2008, patients received high-dose melphalan two days prior to stem cell infusion. The policy was then changed, and patients began to receive stem cell infusions the day after receiving melphalan, sometimes as little as eight hours later.

Thirty-four percent of patients were treated with melphalan two days prior to transplantation, while 66 percent received melphalan one day before the transplant. The median dose of melphalan administered (190 mg/m² two days prior to transplant or 182 mg/m² one day prior to transplant) and the median number of stem cells infused (4.7 million cells/kg two days after melphalan or 5.1 million cells/kg one day after melphalan) were similar for both groups.

Likewise, time until stem cell engraftment and recovery of blood cell counts were similar for the two groups.

Responses were evaluated six to eight weeks following transplantation. The overall response rates for patients who received melphalan two days prior to transplantation and one day prior to transplantation were similar (96 percent versus 95 percent, respectively).

The one-year progression-free survival rates (90 percent versus 87 percent) and one-year overall survival rates (96 percent versus 99 percent) were also similar.

For more information, please see the study in the European Journal of Haematology ^[2] (abstract).