Gertz, Morie A.

AbstractDetection of myeloma progression (PD) relies on serial 24‐h urinary M protein measurements in patients without measurable serum M spike. We examined whether serial difference free light chain (dFLC) levels could be used as a surrogate for serial 24‐h urine M protein measurements in monitoring for PD in patients with baseline measurable urine M protein. We studied 122 patients who had serial measurement of urine M protein and serum FLC and had demonstrated PD. The median increase in dFLC with progression as defined by urine M spike was 110% (IQR: 55‐312) and median absolute increase was 74 mg/dL; while 89% of patients had dFLC increase ≥ 25%, 94% had absolute increase in dFLC > 10 mg/dL, and 98% met at least 1 of these 2 criteria at PD. In patients with baseline measurable serum FLC (n = 118), 89% had increase in dFLC ≥ 25%, 97% had dFLC increase of > 10 mg/dL, and 98% had 1 of the 2. We conclude that serial dFLC assessments can be used in place of serial 24‐h urine protein assessments during myeloma surveillance to monitor for PD. Once patients have an absolute increase in dFLC of >10 mg/dL from the nadir, a 24‐h urine collection can then be assessed to document PD as per the International Myeloma Working Group criteria.

AbstractMonoclonal gammopathy of renal significance (MGRS) has introduced a new perspective to several well-known disease entities impacting nephrology, haematology and pathology. Given the constantly changing disease spectrum of these entities, it is clinically imperative to establish diagnostic and treatment pathways supported by evidence-based medicine. MGRS is a disease of the kidney, secondary to plasma cell clonal proliferation or immune dysfunction, requiring therapeutic intervention to eradicate the offending clone. To fully understand the disease(s), it is prerequisite to determine the significance of the findings. The diagnostic work up should be extensive due to the wide heterogeneity of clinical presentation, ultimately necessitating kidney biopsy. Particular patient profiles such as AL amyloidosis, which may be diagnosed through biopsies of other tissues/organs, may be an exception. Treatment decisions should be formulated by multi-disciplinary consensus: nephrologists, haematologists and pathologists. The ultimate goal in managing MGRS is eradication of the offending plasma cell clone which requires targeted chemotherapy and, in eligible cases, haematopoietic stem cell transplantation. We present a review of diagnostic procedures, treatment options and advances in the last few years in the management of MGRS in an effort to acquaint specialists with this new face of several older diseases.

Background: Heart involvement is the most important prognostic determinant in AL amyloidosis patients. Echocardiography is a cornerstone for the diagnosis and provides important prognostic information. Methods and Results: We studied 754 patients with AL amyloidosis who underwent echocardiographic assessment at the Mayo Clinic, including a Doppler-derived measurement of stroke volume (SV) within 30 days of their diagnosis to explore the prognostic role of echocardiographic variables in the context of a well-established soluble cardiac biomarker staging system. Reproducibility of SV, myocardial contraction fraction, and left ventricular strain was assessed in a separate, yet comparable, study cohort of 150 patients from the Pavia Amyloidosis Center. The echocardiographic measures most predictive for overall survival were SV index <33 mL/min, myocardial contraction fraction <34%, and cardiac index <2.4 L/min/m 2 with respective hazard ratios (95% confidence intervals) of 2.95 (2.37–3.66), 2.36 (1.96–2.85), and 2.32 (1.91–2.80). For the subset that had left ventricular strain performed, the prognostic cut point was −14% (hazard ratios, 2.70; 95% confidence intervals, 1.84–3.96). Each parameter was independent of systolic blood pressure, Mayo staging system (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and troponin), and ejection fraction on multivariable analysis. Simple predictive models for survival, including biomarker staging along with SV index or left ventricular strain, were generated. Conclusions: SV index prognostic performance was similar to left ventricular strain in predicting survival in AL amyloidosis, independently of biomarker staging. Because SV index is routinely calculated and widely available, it could serve as the preferred echocardiographic measure to predict outcomes in AL amyloidosis patients.

SummaryThe optimal duration of induction therapy (IT) in transplant‐eligible multiple myeloma (MM) patients in not well defined, resulting in a wide variation in clinical practice. The objective of our study was to determine whether the duration of IT in patients undergoing upfront autologous stem cell transplantation (ASCT) has an impact on progression‐free survival (PFS) in the era of proteasome inhibitors and immunomodulatory drugs. A total of 596 patients who underwent ASCT at Mayo Clinic between 2007 and 2014 were included. The patients were divided into two cohorts based on the duration of IT: IT ≤ 4 and IT > 4 months. At a median follow‐up of 54·5 months from ASCT, the median PFS in the IT ≤ 4 group was 28 months [95% confidence interval (CI), 25–33], compared to 26 months in the IT > 4 group (95% CI, 24–31) [P = 0·605]. There was no significant difference in overall survival (OS) in the two groups (P = 0·904). The lack of impact of IT duration on PFS and OS was consistent in subgroups with high‐risk features at diagnosis (International Staging System III or high‐risk cytogenetics) and different depths of pre‐transplant response [≥very good partial response (VGPR) and <VGPR]. In conclusion, prolonging the duration of IT beyond 4 months does not impact survival in patients with newly diagnosed MM who complete a single line of IT followed by consolidation with ASCT.

AbstractResponse rates in newly diagnosed multiple myeloma have improved dramatically with the introduction of highly effective novel therapies. However, survival in patients achieving optimal responses to initial treatment can vary significantly, and new prognostic indicators are required to improve risk stratification. We investigated the relationship between time to plateau (TPlat) and survival in 1099 newly diagnosed patients treated with novel agents at our institution from 2005 to 2015.TPlatwas defined as time from initiation of first‐line therapy to best response to first‐line therapy. The medianTPlatwas 4.9 months (0.7‐58.6) and plateau duration was 1.8 years (0.2‐11.0). Patients who required > 120 days to achieve a plateau had longer modified overall survival (mOS) and progression free survival (mPFS) calculated from a landmark of best response (P < .001 for both comparisons). Statistically significant improvement in mOS was retained in subgroup analysis based on age and whether patients received upfront autologous hematopoietic stem cell transplantation (ASCT) (P < .001 for all comparisons). Our results suggest that patients who respond more gradually to initial therapy (TPlat > 120 days) experience longer survival compared to more rapid responders. Patients with a prolongedTPlatcould represent an “ongoing responder” phenotype that portends a survival advantage independent of treatment with upfront ASCT, depth of response, and biologic markers such as ISS stage and cytogenetic risk.

Key Points λ Light chain AL amyloidosis is associated with a shorter PFS and OS compared with κ. Light chain type predicts likelihood of organ involvement in AL amyloidosis.