I visited Mayo Clinic yesterday (Thursday) at the end of my 12th cycle on the trial drug CC-4047 with dexamethasone. Bottom line: M-Spike went down from 1.1 to 1.0 g/dL. In addition, IgG dropped from 1350 to 1160 mg/dL, strongly suggesting that the decrease is real and not just a testing anomaly.
The doctor used the work "plateau," and pointed out that the M-Spike hasn't really increased since last August, when it was lower than it had been in the previous three years. She even referred to the possible management of myeloma as a chronic illness rather than a fatal one, though we agreed that we don't yet know if that is appropriate in my case.
More information coming soon, in exhausting detail as always :-)