Scientists May Have Solved Mystery of Multiple Myeloma Relapse

Researchers target how cancer cells avoid treatment.

Among the main problems in the treatment of multiple myeloma is the rate of relapse in most patients treated with current therapies.

A study presented by the Yale Cancer Center on December 6, 2015 at the 57th annual meeting of the American Hematologic Society in Orlando, Florida, may have uncovered the root of this ongoing problem.

Following diagnosis, patients are treated with drugs from the immune modulating class, including Revlimid or Pomalyst, which initially show efficacy in treating the disease. However, these drugs often fail to prevent relapse in most patients due to residual cancer cells that evade treatment.

To determine the mechanism behind this, the researchers examined the remaining myeloma cells, which revealed a previously undiscovered biologic pathway induced by immune modulating drugs.

These drugs ultimately enable the residual cancer cells to survive and proliferate, the study noted.

"In this case, the pathway involved the loss of a protein called MBD3 that allows tumor cells to become more like stem cells and persist," said first author Rakesh Verma, a postdoctoral associate in hematology.

Researchers hope that preserving this protein may help to inhibit cancerous cells from evading therapy.

"Preventing the degradation of MBD3 protein will make it difficult for myeloma cells to escape this class of drugs," said senior author Madhav Dhodapkar, professor of immunobiology and chief of Hematology. "Being able to target the cells that lead to relapse is essential to curing myeloma."