Citations

e20033 Background: HDMTX is an important component of lymphoma therapy due to its central nervous system penetration. Although HDMTX can be safely administered to most patients, it can cause significant toxicity with those who have prolonged exposure to high plasma concentrations of MTX due to delayed elimination. Therefore, serum MTX concentration monitoring is still a standard approach for identifying patients at high risk of developing MTX toxicity. A majority of MTX is excreted within the first 48 hours of infusion. Higher MTX plasma concentrations at 48 hrs increase the likelihood of delayed MTX elimination. This study will assess baseline characteristics associated with high 48-hour MTX levels (≥ 1µM) which has been associated with increased risk of complications. Methods: A retrospective review of the electronic medical record was conducted to identify lymphoma patients who received HDMTX from 1/1/2002 to 12/31/18. Baseline demographics including age, gender, comorbidities, body surface area, BMI, weight and baseline chronic kidney disease (CKD) were recorded. Demographics, HDMTX dosing per protocol (3.5g/m2 vs 8g/m2), HDMTX adjusted by renal function (CrCl < 100), and ratio of MTX dose to BSA (MTX/BSA) were compared to 48 hour MTX levels. Analysis was performed in JMP 15. Results: 2553 cycles were of HDMTX were identified. There was a significant association of increasing age, (p = 0.039), male patients (p < 0.001), 8g/m2 dosing (p < 0.001), higher MTX dose (p < 0.001), MTX/BSA (p < 0.001), GFR by CKD-EPI (p < 0.001) and lower number of comorbidities (p < 0.001) with 48-hour MTX levels ≥1. There was no significant association of 48-hour MTX levels ≥1 and GFR by Cockcroft-Gault (p = 0.73), baseline CKD (p = 0.78), and renal adjusted HDMTX (p = 0.52). Multivariate analysis revealed significance for MTX/BSA, gender, BSA, GFR by CKDEPI (p < 0.001), and age (P = 0.0002). Conclusions: Hematologists should be aware that age, gender, GFR by CKD-EPI, and ratio of MTX dose to BSA are associated with elevated 48-hour MTX levels ≥1.

8549 Background: Proteinuria evaluation is essential for diagnosing and monitoring of renal involvement in light chain (AL) amyloidosis. A 24 hour protein collection (24h UP) is the gold standard for proteinuria assessment however it is cumbersome and can be inaccurate. A spot urine albumin to creatinine ratio (uACR) has been proposed as a convenient method to estimate 24hUP. We aimed to validate the correlation between uACR and 24hUP in a large cohort of patients. Methods: We retrospectively studied systemic AL amyloidosis patients evaluated between 2010 and 2019 at Mayo Clinic, with a uACR and 24hUP collected less than 7 days apart. Linear regression analysis was used to construct a prediction model for 24hUP with uACR as the primary predictor. Possible confounders (age, gender, body mass index, morning versus afternoon spot urine collection, estimated glomerular filtration rate) for the primary relationship between uACR and 24h UP were evaluated in the model. We used receiver operating characteristic (ROC) analysis to identify the best uACR cutoff to predict significant proteinuria (defined as a 24hUP > 500mg). Results: We included 665 patients, with a median age of 66 years (IQR 59-72). The spot urine was collected in the morning (before 1200 hours) in 382 (57%) patients, and in the afternoon in 283 (43%) patients. The median 24hUP was 321 (IQR 129-2512.5) mg, median uACR was 107 (IQR 13.5-1845) mg/g, and median serum creatinine was 1.2 (IQR 1-1.8) mg/dL. The uACR correlated well with 24h UP (Pearson’s r= 0.83, 95% CI 0.80-0.85). Linear regression showed that E (24h UPi) = 362 + 1.05(uACRi), and this model was statistically and clinically significant (p < 0.001 and R2 of 0.68, respectively). Age, gender, body mass index, eGFR, and time of day of spot urine collection did not confound the primary relationship between uACR and 24hUP, and no collinearity was observed. A uACR cutoff of > 280 mg/g was the best predictor of a 24hUP > 500 mg (area under the ROC curve 0.98, sensitivity 92%, specificity 97%). For simplicity, we assessed the predictive value of uACR > 300 mg/g for 24h UP > 500 mg. Among patients with 24huACR > 300 mg/g 264 (96%) had a 24hUP > 500 mg, and 31 (7%) of patients with uACR < 300 mg/g had a 24h UP > 500 mg (p < 0.001). Conclusions: In systemic AL amyloid patients, we showed that uACR on a random urine sample correlated well with 24h UP, and can be used to estimate proteinuria with a linear regression model. Based on these findings, and the convenience of uACR testing for patients, we propose that uACR should be used to monitor renal response to AL amyloidosis therapy.

8516 Background: The role of induction therapy prior to autologous stem cell transplant (ASCT) in immunoglobulin light chain (AL) amyloidosis remains controversial. Data on the prognostic impact of response to induction in a transplanted cohort are lacking. The aim of this study was to assess the impact of response to induction therapy on survival in patients undergoing ASCT for AL amyloidosis. Methods: We conducted a retrospective study of all newly diagnosed AL amyloidosis patients who received induction prior to ASCT between January 2007 and August 2017 at Mayo Clinic, Rochester, Minnesota. Patients receiving only corticosteroids prior to transplant were excluded as were those with an involved light chain of less than 5 mg/dL (not measurable for response). Results: 134 patients met inclusion criteria. The median age at diagnosis was 60 (range 36-74) and 85 (63%) were men. The most commonly used induction regimen was proteasome inhibitor-based (73.1%, n=98). The overall response rate to induction was 83% (complete response 17%, very good partial response 30% and partial response 36%). With a median follow up of 56.5 months, the median PFS and OS was 48.5 months and not reached, respectively. Response depth to induction therapy was associated with improved PFS and OS and was independent of the bone marrow plasma cell percentage. The median PFS was not reached for patients achieving ≥VGPR prior to ASCT and 33.8 months for patient achieving PR or less (P=0.001). The median OS was longer in patients with deeper responses (not reached for patients achieving ≥VGPR vs. 128 months for patients achieving PR or less (P=0.02). On multivariable analysis, independent predictors of OS were melphalan conditioning dose (RR= 0.38; P=0.018) and depth of response prior to transplant (RR 2.52; P=0.039). Conclusions: Hematologic response prior to transplant predicts post-transplant outcomes in patients with AL amyloidosis. [Table: see text]

AbstractMetaphase cytogenetic abnormalities, plasma cell proliferation index (PCPro), and gain 1q by fluorescence in situ hybridization (FISH) are associated with inferior survival in newly diagnosed multiple myeloma (MM) treated with novel agents; however, their role in risk stratification is unclear in the era of the revised International Staging System (R-ISS). The objective of this study was to determine if these predictors improve risk stratification in newly diagnosed MM when accounting for R-ISS and age. We studied a retrospective cohort of 483 patients with newly diagnosed MM treated with proteasome inhibitors and/or immunomodulators. On multivariable analysis, R-ISS, age, metaphase cytogenetic abnormalities (both in aggregate and for specific abnormalities), PCPro, and FISH gain 1q were associated with inferior progression-free (PFS) and overall survival (OS). We devised a risk scoring system based on hazard ratios from multivariable analyses and assigned patients to low-, intermediate-, and high-risk groups based on their cumulative scores. The addition of metaphase cytogenetic abnormalities, PCPro, and FISH gain 1q to a risk scoring system accounting for R-ISS and age did not improve risk discrimination of Kaplan-Meier estimates for PFS or OS. Moreover, they did not improve prognostic performance when evaluated by Uno’s censoring-adjusted C-statistic. Lastly, we performed a paired analysis of metaphase cytogenetic and interphase FISH abnormalities, which revealed the former to be insensitive for the detection of prognostic chromosomal abnormalities. Ultimately, metaphase cytogenetics lack sensitivity for important chromosomal aberrations and, along with PCPro and FISH gain 1q, do not improve risk stratification in MM when accounting for R-ISS and age.

Abstract Background Studies comparing all treatment options for frequently-relapsing/steroid-dependent (FR/SD) minimal change disease (MCD) in adults are lacking. Methods Medical records of 76 adults with FR/SD MCD who were treated with corticosteroids as the first-line therapy were reviewed. Treatment options were compared for the time to relapse, change of therapy and progression (relapse on full-dose treatment). Results Second-line treatments included rituximab (RTX; n = 13), mycophenolate mofetil (MMF; n = 12), calcineurin inhibitors (CNI; n = 26) and cyclophosphamide (CTX; n = 16). During the second-line treatments, 48 (71.6%) patients relapsed at median 17 (range 2–100) months. The majority of relapses occurred during dose tapering or off drug. Twenty of 65 (30.8%) changed therapy after the first relapse. The median time to relapse after the second line was 66 versus 28 months in RTX versus non-RTX groups (P = 0.170). The median time to change of treatment was 66 and 44 months, respectively (P = 0.060). Last-line treatment options included RTX (n = 8), MMF (n = 4), CNI (n = 3) and CTX (n = 2). Seven (41.2%) patients had a relapse during the last-line treatment at median 39 (range 5–112) months. The median time to relapse was 48 versus 34 months in the RTX versus non-RTX groups (P = 0.727). One patient in the RTX group died presumably of heart failure. No major adverse event was observed. During the median follow-up of 81 (range 9–355) months, no patients developed end-stage renal disease. Conclusions Relapse is frequent in MCD in adults. Patients treated with RTX may be less likely to require a change of therapy and more likely to come off immunosuppressive drugs.

Abstract Light chain deposition disease (LCDD) is a systemic disorder characterized by deposition of nonamyloid monotypic light chains throughout the body. Renal dysfunction is a ubiquitous manifestation of the disease. Reports suggest that high-dose chemotherapy and autologous stem cell transplantation may be beneficial in the treatment of LCDD. However, the impact of autologous stem cell transplantation on renal function is unclear. This study retrospectively reviewed the effect of autologous stem cell transplantation on renal function in six patients with LCDD. Two patients had concurrent multiple myeloma, and one patient was on hemodialysis prior to transplantation. Patients received chemotherapy with dexamethasone alone or dexamethasone plus thalidomide prior to transplantation. Conditioning was performed with high-dose intravenous melphalan. All patients survived transplantation, but one sustained multi-organ failure shortly afterwards and died. Another patient required temporary hemodialysis following transplantation. All surviving patients achieved a hematologic response, although one ultimately relapsed and required further chemotherapy. Renal parameters also improved. On average, proteinuria levels decreased by 83% in four patients and increased by 1% in one patient. Creatine clearance calculated by the Modification of Diet in Renal Disease (MDRD) Study prediction equation improved by an average of 40%. This review suggests that autologous stem cell transplantation may be an effective therapy for renal dysfunction associated with LCDD. Clinical Characteristics of LCDD Patients at Presentation Characteristic Number or range Median *Modification of Diet in Renal Disease Study prediction equation Sex 4 male, 2 female Age (years) 35-61 44 Beta-2 microglobulin, μ/ml 3.58-11 4.12 Albumin, g/dl 1.8-4.2 3.85 Creatinine, mg/dl 1.8-5.4 2.45 MDRD*, ml/min 12-50 26.5 Serum M protein, g/dl 0 0 Serum free light chains, mg/dl (n = 5) 2.18-312 19.6 24-hour urine protein, mg 131-10,251 679

Abstract Introduction: High dose melphalan followed by autologous stem cell transplantation (ASCT) is an effective treatment for patients with light chain associated (AL) amyloidosis. Longer patient survival and higher rates of organ response have now been documented by multiple studies. However, predictors of organ response remain unknown. Previously, we have reported the benefits of renal response after ASCT in this population. This study was conducted to investigate the characteristics that would predict renal response after ASCT. Methods: The study was performed retrospectively on consecutive patients that underwent ASCT at our institution from March of 1996 to December of 2004. Exclusion criteria include baseline proteinuria &lt; 1 g/d, dialysis prior to ASCT and lack of laboratory data at follow up to determine renal response. Renal response was defined by &gt; 50% reduction in baseline proteinuria with &lt; 25% decline in renal function as measured by serum creatinine. Treatment related mortality and dialysis dependence prior to meeting criteria of response were viewed as treatment failures. Hematologic response was determined by 50% reduction of monoclonal protein (free light chain) or complete eradication if the monoclonal protein was too small to be quantified. Results: A total of 135 patients met criteria for study. Median age was 56.2 years at the time of transplant, 53.7% were male. Median baseline proteinuria and GFR were 6.4 g/d and 70 ml/min/1.73m2 respectively. Renal response was achieved in 35.6% of the patients while hematologic response was 71.1% in the 128 patients evaluated. Patient’s age, sex, albumin, GFR, proteinuria, conditioning regimen, and hematologic response were evaluated and the following were found to be associated with renal response: albumin (p = 0.001), proteinuria (p = 0.008), and hematologic response (p = 0.0002). The cutoff for albumin was found to be 1.6 mg/dl and proteinuria was 3.5 g/d. Multivariate analysis using a logistic regression model showed hematologic response and proteinuria to be independent predictors of renal response. The impact of proteinuria and hypoalbuminemia was then investigated together (Table 1). When combined, they were a better predictor then either one alone (Hazard ratio = 6.34 for combined, 3.43 for proteinuria, 3.32 for hypoalbuminemia). The combination was also a better independent predictor of renal response in the multivariate analysis. In this group of patients, renal response was associated with longer survival but hematologic response was not (p = 0.02). Discussion: Our study showed that besides hematologic response, baseline serum albumin and proteinuria are independent predictors of renal response in AL patients after ASCT. Hypoalbuminemia and nephrotic range proteinuria, both markers of the severity of renal disease, have strong negative impact on response. This implies that there may be a limit to the reversibility of organ damage even when hematologic response is achieved. This study also points out the importance of organ (renal) response in this disease as hematologic response alone did not predict long term outcome. Our results suggest ASCT should be done early for AL to insure optimal organ response and patient outcome. Table 1 The Effects of Hypoalbuminemia and Proteinuria on Renal Response after ASCT Hypoalbuminemia & Proteinuria No Renal Response Renal Response None 39.3% 60.7% One 66.2% 33.8% Both 81.8% 18.2%

Abstract Introduction: The kidney is affected by immunoglobulin light chain amyloidosis (AL) in more than 50% of patients who present with the disease, but long-term predictors for and outcomes after renal replacement therapy have not been well described in this patient group Patients: 145 patients with AL who participated in Mayo Clinic treatment trials and were monitored for at least 11 years. No patient was lost to follow-up Results: Among patients presenting with renal AL, 42% ultimately received renal replacement therapy compared with 5% of patients who did not have an initial presentation involving the kidney. Table 1. Monoclonal Protein Studies in 145 Patients With Immunoglobulin Light Chain Amyloidosisa Patients, No. (%) Monoclonal Protein Renal Amyloid at Presentation (n=84) Nonrenal Amyloid at Presentation (n=61) a P=.02 l more likely to cause renal presentation None 7 (8) 2 (3) k 6 (7) 12 (20) l 71 (85) 47 (77) Table 2. Characteristics of All 145 Patients With Immunoglobulin Light Chain Amyloidosis Amyloid Renal (n=84) Nonrenal (n=61) P Value Abbreviations: IQR, interquartile range; NA, not applicable. a included in the definition of renal amyloidosis Patients with l immunoglobulin light chain amyloid were significantly more likely to have renal involvement and had significantly greater urinary protein loss than patients with κ or no monoclonal light chain amyloid Age, median (IQR), y 61 (52–67) 62 (55–68) .47 Sex, male/female 52/32 40/21 .72 24-hr urine protein loss, median (IQR), g/d 7.0 (4.4–11.7) 0.3 (0.1–6.4) NAa Creatinine, median (IQR), mg/dL 1.1 (0.9–2.2) 1.1 (0.9–1.3) .22 Cardiac involvement (yes/no) 35/48 48/16 .0001 Table 3 Distribution of Urinary Protein and Creatinine Based on Monoclonal Protein Monoclonal Protein Test k (n=18) l (n=118) None (n=9) P Value Abbreviation: IQR, interquartile range. Patients with renal amyloid who ultimately received dialysis support had significantly higher serum creatinine and 24-hour urine protein levels at presentation. Absence of cardiac involvement at diagnosis predicted an increased likelihood of dialysis All patients (N=145) 24-hr urine protein loss, median (IQR), g/d 0.73 (0.16–2.37) 3.61 (0.35–7.8) 5.68 (0.3–12.2) .001 Creatinine, median (IQR), mg/dL 1.1 (0.9–1.3) 1.1 (0.9–1.3) 1.5 (1.2–1.6) NS Patients with renal amyloid at presentation (n=84) 24-hr urine protein loss, median (IQR), g/d 2.93 (1.1–5.0) 7.2 (4.8–11.8) 7.8 (3.8–12.6) .04 Creatinine, median (IQR), mg/dL 1.0 (0.8–2.6) 1.1 (0.9–2.2) 1.5 (1.1–1.6) NS Table 4 Characteristics of 84 Patients Presenting With Renal Amyloidosis Dialysis Subsequently Not Required Characteristic Required (n=35) (n=49) P Value Abbreviation: IQR, interquartile range. The median time from diagnosis to dialysis was 29.5 months for those that went into renal failure.). However, the actuarial risk reached 50% at 12 years Kaplan-Meier failure curve demonstrating the actuarial time from diagnosis to the start of dialysis therapy N=145 For 38 patients who received dialysis, median survival from day 1 of dialysis was 10.4 months Kaplan-Meier survival of 38 patients from the start of dialysis therapy Age, median (IQR), y 60 (52–67) 62 (52–67) .90 Sex, male/female 21/14 31/18 .76 24-hr urine protein loss, median (IQR), g/d 7.4 (5.0–14.8) 5.9 (3.7–9.1) .03 Creatinine, median (IQR), mg/dL 1.4 (0.9–2.8) 1.1 (0.9–1.5) .01 Cardiac involvement (yes/no) 9/26 26/23 .01 Conclusion: In our study, 26% of all patients with AL ultimately received renal replacement therapy compared with 42% of patients who presented with renal AL specifically. The presenting 24-hour urine protein loss and creatinine values predict which patients will require dialysis. Median survival for patients starting dialysis is less than 1 year. Presence of l light chain amyloid predicts an increased likelihood of renal involvement and, when the kidney is affected, increased proteinuria.