Hello, Rafael Fonseca from the Mayo Clinic in Arizona. I am frequently asked what constitutes a very good partial response in the International Myeloma Working Group response criteria. Now these are patients who have serum and urine M-protein that is still detectable by immunofixation but not on electrophoresis, or that they had a 90% or greater reduction in their serum M-spike, plus a urine monoclonal protein that is less than 100 mg per 24 hours. The importance of this response category is that these are patients who achieved very deep responses to therapy, we would consider them with successful treatment yet still have some residual markers that identify their myeloma symptoms.
Reviewed on January 17, 2017 for clinical relevance.