New drugs ease treatment of multiple myeloma

Science is increasingly commuting the death sentence that is a diagnosis of multiple myeloma. A cancer of the plasma cells that primarily strikes the elderly, multiple myeloma has been deadly because patients have been unable to withstand the aggressive treatment necessary to combat it.

Now that's changing with the use of new drugs combined with refinements in the use and timing of stem cell transplants — therapies minus the devastating side effects of traditional treatment.

Details of the latest therapies for multiple myeloma will be discussed during a unique "town meeting" style program June 15 at Fred Hutchinson Cancer Research Center sponsored by the Leukemia & Lymphoma Society. The free program, open to the general public, is accessible in person, via a live Webcast (or later by Web archive) or by a toll-free phone link.

"New ways of treating multiple myeloma can be seen as a bellweather for progress in the overall search to find ways to turn some once-fatal cancers into chronic illnesses that can be managed, resulting in extended lives," said William Bensinger, M.D., one of the forum's presenters. He is director of Fred Hutchinson's Autologous Stem Cell Transplant Program.

"Where just a few years ago there were few effective treatments for multiple myeloma, now there are many, and some are being combined and timed to help people live longer," he said. "While the goal remains curing cancer by killing every last abnormal cell so it never comes back, in some cancers, keeping the cancer at bay can be a very legitimate interim strategy."

More than 15,000 new cases of multiple myeloma will be diagnosed in the United States this year; median age at diagnosis is 65. About 11,000 persons with the cancer will die this year.

The cancer is not curable using conventional chemotherapy, which has led to the use of new drugs and transplant procedures, including multiple-drug chemotherapies. Therapies being used at Fred Hutchinson include:

Autologous stem cell transplants: These are transplants using the patient's own stem cells, which are given back after chemotherapy and/or radiotherapy. Autologous transplants offer higher initial survival rates, but because they do not produce graft-versus-myeloma effect, they may not result in long-term remission.

Experimental therapies to counter this effect include:

• Targeting radiation to the bone marrow using high-energy radioisotopes. One such isotope, 166-Holmium, is linked to a bone-seeking agent and, when given intravenously, selectively homes to bone and irradiates the major sites of disease in myeloma.
  
  
• Maintenance therapies after autologous transplant. These could prevent recurrences and prolong life. The center is currently evaluating a regimen of thalidomide, bianin and dexamthasone for tolerance and the ability to prevent disease recurrence.

Allogeneic stem cell transplants: These are transplants of stem cells from a matched donor following chemotherapy and/or radiotherapy. These transplants have higher complication rates, but also higher and more durable remission rates. Donors can be related or unrelated to the patient.

Non-ablative allogeneic transplants, also called mini-transplants, are sometimes used for patients who have failed prior autologous transplants or who are not eligible for other types of transplants. Mini-transplants work by using just enough radiation to suppress the patient's immune system without ablating, or wiping out, the bone marrow. The donor cells then fight the cancer. These transplants are much easier on the body and often can be done on an outpatient basis.

Tandem transplant: This approach uses two autologous transplants or an autologous transplant followed by a non-ablative (mini) transplant. The former technique may improve remission rates and survival of patients who do not achieve a remission after the first transplant. The latter is a promising new technique that reduces the toxicities of the high dose allogeneic transplant, which provides substantial anti-tumor effects from the immunologic graft-versus-myeloma effects of the allogeneic transplant. These have lower risks and a complete response rate of approximately 50 percent.

Non-transplant therapies: These are suited for patients with advanced disease or who have failed other therapies. Such therapies include chemotherapy with agents such as Dexamethasone; Melphalan/prednisone; Vincristine, adriamycin and dexamethasone (VAD); boretezomib; thalidomide and revalimid.