Lacy, Martha Q.

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.

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.

Purpose Autologous stem-cell transplantation (ASCT) has been used in patients with immunoglobulin light chain (AL) amyloidosis for more than two decades. Early experience raised concerns regarding safety with high early-mortality rates. Patients and Methods We report 20 years of experience with ASCT for AL amyloidosis at the Mayo Clinic Rochester. In all, 672 consecutive patients receiving ASCT for AL amyloidosis were divided into three cohorts on the basis of date of transplantation (cohort 1, 1996-2002 [n = 124]; cohort 2, 2003-2009 [n = 302]; and cohort 3, 2010-2016 [n = 246]). Results The median age for the entire cohort was 59 years, with patients in cohort 3 being slightly older than those in the other two cohorts (60 v 58 v 54 years for cohorts 3, 2, and 1, respectively; P < .001). Fewer patients in cohort 3 had more than two organs involved (9% v 18% v 19% for cohorts 3, 2, and 1, respectively; P < .001). More patients received pretransplantation therapy in cohort 3 compared with earlier time periods (49% v 38% v 42% for cohorts 3, 2, and 1, respectively; P = .02). Hematologic response was higher in cohort 3 (84% v 79% v 69% for cohorts 3, 2, and 1, respectively; P = .002). Median overall survival for the entire cohort was 122 months and improved over time (not reached v 120 months v 75 months for cohorts 3, 2, and 1, respectively; P < .001). Treatment-related mortality declined over time (2.4% v 8.6% v 14.5% for cohorts 3, 2, and 1, respectively; P < .001). On multivariable analysis, conditioning dose, Mayo stage 2012, and hematologic response were independent predictors of survival. Conclusion ASCT is a highly effective therapy for AL amyloidosis. The improved survival and markedly reduced treatment-related mortality in eligible patients indicate that this will remain an important first-line option even in the era of treatment approaches that use novel agents.

AbstractWaldenström macroglobulinemia (WM) is an immunoglobulin M‐associated lymphoma, with majority of cases demonstrating MYD88 locus alteration, most commonly, MYD88L265P. Owing to low prevalence of the wild‐type (WT) MYD88 genotype in WM, clinically relevant data in this patient population are sparse, with one study showing nearly a 10‐fold increased risk of mortality in this subgroup compared to patients with MYD88L265P mutation. We studied a large cohort of patients with MYD88L265P and MYD88WT WM, evaluated at Mayo Clinic, Rochester, between 1995 and 2016, to specifically assess the impact of these genotypes on clinical course. Of 557 patients, MYD88L265P mutation status, as determined by allele‐specific polymerase chain reaction, was known in 219, and 174 (79%) of those exhibited MYD88L265P, 157 of 174 patients had active disease. Of 45 (21%) patients with MYD88WT genotype, 44 had active disease. The estimated median follow‐up was 7.0 years; median overall survival was 10.2 years (95% CI: 8.4‐16.5) for MYD88L265P versus 13.9 years (95% CI: 6.4‐29.3) for the MYD88WT (P = 0.86). The time‐to‐next therapy from frontline treatment and the presenting features were similar in the two patient populations. For patients with smoldering WM at diagnosis, the median time‐to‐progression to active disease was 2.8 years (95% CI: 2.2‐3.8) in the MYD88L265P cohort and 1.9 years (95% CI: 0.7‐3.1) in the MYD88WT cohort (P = 0.21). The frequency of transformation to high‐grade lymphoma, or the development of therapy‐elated myelodysplastic syndrome was higher in the MYD88WT cohort (16% versus 4% in the MYD88L265P, P = 0.009). In conclusion, MYD88L265P mutation does not appear to be a determinant of outcome, and its presence may not be a disease‐defining feature in WM. Our findings warrant external validation, preferably through prospective studies.

AbstractExperience with intensive chemotherapy for relapsed/refractory multiple myeloma (RRMM) using VDT PACE regimen and its modifications (VDT PACE‐like regimens: VPLRs) outside TOTAL THERAPY trials is limited. We analyzed the outcomes of 141 patients with RRMM who received VPLRs at our center between 2006 and 2017 in an intent‐to‐treat analysis. Median age was 59.7 years and 66.7% of patients were male. A median of 2.2 years (range 0.02‐11.4) separated diagnosis of myeloma and inititation of VPLR. High‐risk cytogenetics were present in 52.4% patients. Patients received a median of 4 (range 1‐14) prior therapies, including stem cell transplant (SCT) in 66.7% patients. Ninety‐five (67.4%) patients received VDT PACE, 20 (14.2%) patients received VD PACE and 26 (18.4%) patients received other VPLRs. Patients received a median of 1 cycle (range 1‐9) of VPLR. We observed ≥ minimal response in 68.4%, ≥ partial response (PR) in 54.4% and ≥ very good PR in 10.3% patients. Median progression‐free survival was 3.1 months (95% CI, 1.9‐3.9) and median overall survival (OS) was 8.1 months (CI, 6.2‐9.9). One‐hundred and sixteen (82.3%) patients received some therapy after VPLR; 71 (61.2%) received systemic chemotherapy, while 45 (38.8%) underwent SCT. Median OS for those who received SCT after VPLR was 15.1 months (CI, 10.3‐20.8). Age ≥ 60 years (hazard ratio [HR] 2.3 [CI, 1.4‐3.7]; P = 0.0008) and R‐ISS III stage (HR‐ 2.4 [CI, 1.3‐4.0]; P = 0.003) predicted shorter OS in patients receiving VPLR. VPLRs are effective in heavily pre‐treated RRMM. In fit patients, SCT can be used to consolidate the response to VPLR.

AbstractAchievement of a normal FLC ratio (FLCr) following treatment indicates hematologic response and suggests better outcomes in light chain amyloidosis (AL). We examined if elevated involved free light chain (hiFLC) impacts outcomes in patients achieving normal FLCr. We retrospectively analyzed 345 AL patients who were diagnosed within a 10‐year period (2006‐2015) and had 2 consecutive normal FLCr values after 1st line treatment. Among these, patients with hiFLC at 1st reading of normal FLCr (hiFLC1; n = 166; 48.1%) were compared to those who did not (n = 179; 51.9%). Patients with AL who have hiFLC1 after initial therapy had higher rates of multi‐organ involvement (63.3 vs 46.4%; P = .002) and patients in advanced Mayo stage (42.9 vs 32.2%; P = .04) at diagnosis. The median progression free survival [PFS; 38.2 (95%CI; 26.4, 55.4) vs 67.1 (95%CI; 55.8, 88) months; P = .0002] and overall survival [OS; 94.4 (95%CI; 78, 107.1) vs not reached (NR, 95%CI; 116.1, NR) months; P < .0001] were lower in those who had hiFLC1. A more stringent comparison for patients with 2 consecutive hiFLC (hIFLC2; n = 111; 32.2%) versus not (n = 2234; 67.8%) showed consistent results [PFS; 27.1 (95%CI; 23, 53.8) vs 63.3 (95%CI; 55.4, 77) months; P < .0001 and OS; 78 (95% CI; 54.6, 98.8) vs NR (95%CI; NR, NR); P < .0001]. This poor prognostic impact of hiFLC on survival was independent of serum creatinine, Mayo stage, negative immunofixation status and inclusion of transplant in initial therapy on multivariate analysis. Hence, persistent elevation of iFLC predicts poor prognosis even among patients achieving normal ratio after initial therapy in AL.