Current therapy of multiple myeloma
There is currently no cure for multiple myeloma. The therapy aims at delaying a relapse and alleviating symptoms, and is based on four pillars:
- Chemotherapy with alkylating agents
- Immune modulating treatments (bortezomib, thalidomide, lenalidomide)
- Corticosteroids and
- Stem cell transplantation
The initial choice of therapy depends upon the patient's health, age, ability to undergo stem cell transplantation in the future and disease characteristics denoting the severity and risk of the individual multiple myeloma tumor clone. For each patient these different therapeutic options and their combinations are carefully weighed by the oncologist to achieve the greatest benefit for the patient. The recent introduction of bortezomib and thalidomide or lenalidomide into the therapy has markedly improved the therapy with longer remission times and disease free intervals, but still cannot cure it. Despite some progress there is still an urgent medical need for novel drugs that target the myeloma cells in the blood and bone marrow by novel mechanisms.
The combination of high dose chemotherapy (often with melphalan) followed by autologous stem cell transplantation is a key element in the effective therapy of multiple myeloma. High-dose chemotherapy before transplantation is intended to wipe out the myeloma cells, but the chemotherapeutic agents also destroy the normal “healthy” stem cells in the bone marrow which are essential for maintaining normal numbers of red and white blood cells and platelets in the blood. Such intensive chemotherapeutic treatment puts the patient at risk for serious infections and bleeding until reconstitution of his own blood, immune cells and platelets after transplantation. Transplantation, when successful, prolongs survival, leads to remission, and, infrequently, cures multiple myeloma. However, the high-dose chemotherapy given before transplantation usually fails to kill all of the myeloma cells, allowing the condition to eventually relapse.