Cancer Health Center

There are two main types of refractory myeloma patients:

• Primary refractory patients who never achieve a response and progress while still on induction chemotherapy.
• Secondary refractory patients who do respond to induction chemotherapy but do not respond to treatment after relapse.

A subgroup of patients who do not achieve a response to induction chemotherapy have stable disease and enjoy a survival prognosis that is as good as that for responding patients.[1,2] When the stable nature of the disease becomes established, these types of patients can discontinue therapy until the myeloma begins to progress again. Others with primary refractory myeloma and progressive disease require a change in therapy. (Refer to the Treatment for Multiple Myeloma section of this summary for more information.)

The myeloma growth rate, as measured by the monoclonal (or myeloma) protein-doubling time, for patients who respond to their initial therapy increases progressively with each subsequent relapse, and remission durations become shorter and shorter. Marrow function becomes increasingly compromised as patients develop pancytopenia and enter a refractory phase; occasionally, the myeloma cells dedifferentiate and extramedullary plasmacytomas develop. The myeloma cells may still be sensitive to chemotherapy, but the regrowth rate during relapse is so rapid that progressive improvement is not observed.

Current Clinical Trials

Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with refractory multiple myeloma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References:

1. Riccardi A, Mora O, Tinelli C, et al.: Response to first-line chemotherapy and long-term survival in patients with multiple myeloma: results of the MM87 prospective randomised protocol. Eur J Cancer 39 (1): 31-7, 2003.
2. Durie BG, Jacobson J, Barlogie B, et al.: Magnitude of response with myeloma frontline therapy does not predict outcome: importance of time to progression in southwest oncology group chemotherapy trials. J Clin Oncol 22 (10): 1857-63, 2004.