What Is Active Myeloma?
In most cases, active MM is least complicated biologically and is easiest to treat early in the disease course. The amount of monoclonal protein (M-protein) secreted by myeloma cells is lowest when the disease is still asymptomatic, in the MGUS and smoldering myeloma phase.
As the disease progresses, the myeloma cells grow in number, resulting in higher levels of monoclonal protein. When biomarkers show that MM either already is, or will soon become symptomatic, treatment is initiated.
Frontline Therapy and Types of Remissions
The first line of treatment is also called "induction" or "frontline" therapy. In killing myeloma cells, therapy reduces the amount of monoclonal protein and halts further medical problems related to multiple myeloma. Current frontline combination therapy usually produces a deep and durable response or "remission," during which time the production of monoclonal protein levels off or "plateaus." Remissions are categorized as follows:
- In a complete response (CR), monoclonal protein is no longer detectable.
- A very good partial response (VGPR) indicates at least a 90% drop in monoclonal protein.
- A partial response (PR) indicates at least a 50% drop in monoclonal protein.
- Minimal response (MR) indicates a drop in monoclonal protein of at least 25%.
- Stable disease (SD) means that the level of monoclonal protein neither decreased nor increased.
Remissions are often maintained for long periods of time with continuous or "maintenance" therapy. But because myeloma is a remitting and relapsing disease, in most cases the myeloma cells that have resisted prior therapy will begin to grow again in time, monoclonal protein levels will once again increase, and a relapse will occur.
Your doctor will order various tests and monitor your results closely in order to treat you at the appropriate time — not too soon, but before you experience medical problems related to your MM. Treatment is started with a new regimen, or with one that worked well for you as induction therapy. In most, but not all cases, the response to treatment for this first relapse is shorter, and may not be as deep, as the response to frontline therapy was.
There are many treatment options for successive relapses. Most patients do well for long periods of time — many live for decades after diagnosis — but in most cases, responses become shorter and less deep with each subsequent relapse, and the disease eventually becomes refractory — unresponsive — to available treatments.