The results of a recent study suggest that donor stem cell transplants may not be necessary as part of first line therapy for newly diagnosed multiple myeloma patients. These findings were presented at the recent European Hematology Association (EHA) meeting held in Barcelona, Spain.

Despite its frequent use in the treatment of multiple myeloma, stem cell transplantation remains a risky procedure with many possible complications.

Patients can either receive their own stem cells during this procedure (autologous stem cell transplant) or receive the stem cells from a healthy donor (allogeneic stem cell transplant). An allogeneic transplant has the potential to cure a myeloma patient. However, donors must have a tissue type that matches the recipient in order to minimize rejection, which happens when the transplanted cells recognize the patient’s cells as foreign and trigger an immune response.

Due to potential rejection, transplants with donor cells are riskier than transplants using the patient’s stem cells. Therefore, the role of allogeneic transplants in the treatment of myeloma is disputed by clinicians and researchers.

This study was designed to evaluate the value of allogeneic stem cell transplantation as part of first line therapy for newly diagnosed myeloma patients.

All patients included in the study were previously enrolled in a Phase 3 trial in which they received thalidomide (Thalomid) induction therapy followed by high-dose melphalan (Alkeran) therapy and autologous stem cell transplantation.

Of those participants, 100 patients had an eligible sibling donor and received total body irradiation and an allogeneic transplant between two and six months after high-dose melphalan therapy. Another 122 patients did not have a donor and, instead, started thalidomide maintenance therapy.

Ninety-six percent of patients who received an allogeneic transplant responded to treatment, with 35 percent achieving a complete response, 35 percent achieving a very good partial response, and 26 percent achieving a partial response.

By comparison, 95 percent of patients who underwent thalidomide maintenance also responded to treatment, with 20 percent achieving a complete response, 55 percent achieving a very good partial response, and 20 percent achieving a partial response.

Researchers found that the average time patients experienced no progression in their disease was 29 months for both the donor transplant group and the thalidomide maintenance group.

At five years post-high dose melphalan therapy, the average overall survival rate had not yet been reached; however, 60 percent of donor transplant patients were alive versus 55 percent of patients receiving thalidomide maintenance therapy.

Based on the similar responses and survival rates, the researchers concluded that there was no improvement of patient outcome by including allogeneic transplantation instead of thalidomide maintenance as part of first line therapy in newly diagnosed multiple myeloma patients.

For more information, see abstract 1098 on the EHA meeting website.