Next generation flow cytometry for MRD detection in patients with AL amyloidosis.

The treatment of AL amyloidosis aims to eradicate the plasma cell clone and eliminate toxic free light chain production. Only in a minority of patients the plasma cell clone is completely eradicated; residual light chain production may still exist while clonal relapse may occur. We used sensitive next-generation flow cytometry (NGF) to detect minimal residual disease (MRD) in AL amyloidosis patients at complete haematologic response. MRD evaluation was feasible in 51 of 52 (98%) tested patients and at a median sensitivity of 2.3 × 10-6 MRD was undetectable in 23 (45%). An organ response occurred in 86% of MRDneg vs 77% in MRDpos; renal response in 15/17(88%) of MRDneg vs in 14/16(87.5%) of MRDpos and cardiac response in 10/10(100%) of MRDneg vs 11/15(73%) of MRDpos patients. After a median follow-up of 24 months post MRD testing, no MRDneg patient had a haematologic relapse vs 6/28(21%) MRDpos (p = .029). Pooling haematologic and organ progressions, 9 (32%) MRDpos patients had disease progression vs only 1 (4%) MRDneg patient (p = .026). In conclusion, MRD detection using NGF has profound clinical implications, so that AL patients with undetectable MRD have a very high probability of organ response and a very low probability of haematologic relapse.

Evolving chemotherapy options for the treatment of myeloma kidney: a 40-year perspective.

Kidney impairment (KI) at the time of initial diagnosis is common in myeloma. The improvement of kidney function and the reversal of KI are of utmost importance. Recent advances have made it possible to reverse acute kidney damage due to myeloma in most patients, at least if treatment is immediately implemented. Immediate antimyeloma therapy and appropriate hydration are the most commonly used treatment modalities for the management of acute KI related to myeloma. Mechanical approaches can only temporarily reduce the free light-chain load, and without effective chemotherapy they are probably not able to significantly improve kidney function. However, the role of mechanical approaches together with effective chemotherapy is still being explored. Thalidomide, lenalidomide, and bortezomib have improved the survival of myeloma patients, but they have also improved the outcome of patients presenting with KI. Thalidomide is safe to use on patients with KI without dose adjustments. Lenalidomide needs dose modification, but it can improve kidney function in many patients. Bortezomib seems to be the agent of choice for most patients presenting with KI without dose modifications. This review focuses on the management of patients presenting with "myeloma kidney" using modern chemotherapy approaches, especially novel agents.

Renal impairment is not an independent adverse prognostic factor in patients with multiple myeloma treated upfront with novel agent-based regimens.

Abstract Renal impairment (RI) is a common presenting complication of multiple myeloma associated with significant morbidity and early mortality, while it has been associated with inferior survival in patients treated with conventional regimens. We assessed the impact of RI in 203 unselected consecutive patients treated upfront with novel agents (thalidomide, lenalidomide, bortezomib). RI was assessed by the estimated glomerular filtration rate (eGFR). RI (eGFR <60 mL/min) was present in 93 (45.8%) of patients at diagnosis and was associated with advanced age, advanced International Staging System (ISS) stage, poorer performance status, hypercalcemia, urine Bence-Jones proteinuria, anemia and thrombocytopenia. Myeloma response rates were similar for patients with or without RI. In univariate analysis RI was associated with shorter survival and a higher rate of early death (7% vs. 3.5%); however, when adjusted for other prognostic factors, RI was not independently associated with survival. In conclusion, in unselected newly diagnosed patients treated with novel agent-based therapies, RI is not independently associated with inferior survival, probably due to the significant activity of novel agents even in the context of RI.