Muchtar, Eli

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]

8026 Background: CLL progression and CLL-related complications (infections and second malignancies) were the leading cause of death (COD) in a prospective cohort of CLL patients (Strati, BJH 2017). The CLL-IPI integrates major clinical and molecular prognostic factors and stratifies patients into 4 risk groups with distinct prognosis. It is unknown if COD differs according to CLL-IPI risk group in patients with newly diagnosed CLL. Methods: Patients diagnosed with CLL between 1/2000-12/2019 and seen within 1 year of diagnosis were identified from the Mayo Clinic CLL database. Cumulative incidences of cause-specific death were analyzed using Gray’s test, with deaths from different causes treated as competing events and deaths from unknown causes excluded. Results: 1276 patients were included in this study. The median age at diagnosis was 63 years (range 24-92), and 880 (69%) were male. Based on CLL-IPI score, 449 (35%) had low risk disease, 443 (35%) had intermediate risk disease, and 384 (30%) had high/very high risk disease. Median follow-up time for the study was 6 years; 286 deaths occurred. The COD was CLL progression in 99 (35%), infection in 16 (6%), second malignancy in 47 (16%), CLL-unrelated in 59 (21%), and unknown in 65 (23%) patients. The rates of death due to CLL progression were higher (17.3% at 5 years; 30.3% at 10 years) than the rates due to CLL-related complications (5.7% at 5 years; 12.9% at 10 years) or due to CLL-unrelated causes (8.6% at 5 years; 16.9% at 10 years) in the CLL-IPI high/very high risk group, but not the CLL-IPI low or intermediate risk group (Table). A higher CLL-IPI risk group was associated with a higher rate of death due to CLL progression ( P < 0.001), as well as a higher rate of death due to CLL-related complications ( P = 0.013), and CLL-unrelated causes ( P < 0.001). Conclusions: Causes of death in newly diagnosed CLL patients differ according to their CLL-IPI risk group. In patients with high/very high risk CLL, improving CLL disease control with novel agents seems justified. In patients with low/intermediate risk CLL, there should be increased efforts to reverse immune dysfunction to reduce infections and second malignancies. [Table: see text]

Abstract To study the impact of dose modification and temporary interruption of ibrutinib in routine clinical practice, we conducted a retrospective study of consecutive CLL patients treated with ibrutinib outside the context of a clinical trial at Mayo Clinic, (Rochester, MN) from 11/2013 to 12/2017. Of 209 patients, 131 (74%) had unmutated IGHV , 38 (20%) had TP53 disruption, and 47 (22%) were previously untreated. A total of 87/209 (42%) patients started reduced dose ibrutinib (<420 mg daily; n = 43, physician preference; n = 33, concomitant medications; and n = 11, other). During 281 person‐years of treatment, 91/209 patients had temporary dose interruption (54%, nonhematologic toxicity; 29%, surgical procedures; 10%, hematologic toxicity; and 7%, other). After a median follow‐up of 24 months, the estimated median event‐free survival (EFS) was 36 months, and median overall survival (OS) was not reached. On multivariable analyses, temporary ibrutinib interruption (hazard ratio [HR]: 2.37, P = .006) and TP53 disruption at ibrutinib initiation (HR: 1.81, P = .048) were associated with shorter EFS, whereas only TP53 disruption (HR: 2.38, P = .015) was associated with shorter OS. Initial ibrutinib dose and dose modification during therapy did not appear to impact EFS or OS. These findings illustrate the challenges associated with continuous oral therapy with ibrutinib in patients with CLL.

e19519 Background: NSMM is a rare subtype of myeloma that has not been well characterized in the era of novel agent induction therapy. Thus, we evaluated the clinical and cytogenetic features of patients with newly diagnosed NSMM evaluated at our institution. Methods: We evaluated all NSMM patients seen at the Mayo Clinic, Rochester from 2008-2017 based on the absence of a detectable monoclonal protein in their serum and urine electrophoresis and having a concurrent involved serum immunoglobulin light chain of less than 5 mg/dL. Survival analysis was performed by the Kaplan-Meier method and clinical and cytogenetic features were reported descriptively. Results: This cohort consisted of 30 consecutive patients with NSMM with a median age of 62 years (40-79) of which 16 (53%) were male. The median bone marrow plasma cell involvement was 70% (Range: 0 – 100). There were 3/25 (12%) patients who presented with a creatinine of 2 mg/dL or greater and 6/23 (26%) patients who presented with hypercalcemia (11 mg/dL or greater). The ISS classification of this cohort is as follows: Stage 1- 8 (36%) patients, Stage 2- 3 (14%) patients and Stage 3- 11 (50%) patients. There were 6 (21%) out of 28 patients with high risk cytogenetics (either del 17p, t(4;14), t(14;16) or t(14;20). The distribution of primary cytogenetic abnormalities among this cohort was as follows: t(11;14) – 16 (57%), t(4;14) – 1 (4%), trisomies – 6 (21%) and other - 5 (13%). The median overall survival (OS) for patients in this cohort was 59 months (95% CI: 34 – 64). In comparison to a control cohort of newly diagnosed secretory myeloma patients matched for age, gender and year of diagnosis in a 1:2 ratio, the median OS was worse for the NSMM cohort but this was not statistically significant (59 vs. 92 months, p = 0.257). Conclusions: Patients diagnosed with NSMM had a predisposition towards having a t(11;14) primary cytogenetic abnormality. In the era of novel agent induction therapy, they may have a survival outcome that may be worse than newly diagnosed secretory myeloma patients.

8039 Background: Treatment of MM has evolved significantly over the past decade, with increasing use of multi-drug combinations for initial therapy. In addition, supportive care approaches have also improved. We examined how these improvements have translated to survival outcomes in patients with newly diagnosed MM. Methods: Patients (n=3449) with a diagnosis of MM made between 2004 and 2017 and seen at Mayo Clinic within six months of the diagnosis, were included in this analysis. Patients were divided into three groups based on the year of diagnosis; group 1- 2004-07 (n=831), group 2-2008-12 (n=1161), and group 3-2013-17 (n=1457). Survival of the groups were estimated using Kaplan-Meier method, and compared using log rank test. Results: The median age was 64 years (22 to 96); 60% were male and 40% were female. 14% were >75 years, 33% were aged 65-75 and 53% were <65 years. The median overall survival for the whole cohort was 5.7 years (95%CI; 5.4, 6.3). The median OS for the groups 1, 2 and 3 were 3.9, 6.3 and NR, respectively; p<0.001. The 4-year survival estimates were 50%, 62%, and 75%, respectively. We then explored the improvements in patient subgroups. While all patients experienced improvements in OS over time, improvement in group 3 was most prominent for those >75 years. In patients <65 years, the 4-yr OS for groups 1, 2 and 3 were 57, 71, and 79% respectively. In patients 65-75 years of age, the 4-yr OS for groups 1, 2 and 3 were 48, 60, and 75% respectively. In patients >75 years, the 4-yr OS for groups 1, 2 and 3 were 24, 35, and 56% respectively. While patients with high-risk disease did not see as much benefit in the earlier period, substantial progress was seen in the last group. The 3-yr OS for patients with high-risk cytogenetics were 52, 55, and 73% for groups 1, 2 and 3 compared to 67, 75, and 85% for standard-risk cytogenetics respectively. 2067 patients were staged according to the International Staging System and the median OS for stages 1, 2 and 3 were 6.5, 4.6 and 2.4 in group 1; 9.2, 6.6 and 3.5 in group 2 and NR for any of the stages in group 3. Conclusions: The results confirm continued improvement in survival of newly diagnosed multiple myeloma patients, including elderly and high-risk MM.

8031 Background: Our prior studies identified the prognostic significance of ≥400 cPCs/150,000 analyzed events quantified by MFC in NDMM. We evaluated if a similar quantification of cPCs using MFC can add prognostic value to the current R-ISS classification of NDMM pts. Methods: We evaluated all NDMM pts seen at the Mayo Clinic, Rochester from 2009-2017 who had their peripheral blood samples evaluated by 6-color MFC prior to therapy. The cPCs detected were reported as the number of clonal events/150,000 collected total events. Survival analysis was performed by the Kaplan-Meier method and differences assessed using the log rank test. Results: This cohort consisted of 566 consecutive pts with NDMM with a median age of 66 years (27-95). The distribution of the R-ISS classification of this cohort is as follows: Stage 1- 128 (23%) pts, Stage 2- 369 (65%) pts and Stage 3- 69 (12%) pts. The median number of cPCs was 59 (0-46,412) / 150,000 events. The median time-to-next-treatment (TTNT) and overall survival (OS) for pts with ≥400 cPCs (n = 140, 25%) was 19 months and 46 months compared with 34 months and 77 months for those with < 400 cPCs respectively (n = 426, 75%) (p < 0.001 for both). The median TTNT and OS for pts based on their R-ISS classification as well as with and without the presence of ≥400 cPCs by MFC was as follows in the following Table. Conclusions: Quantifying ≥400 cPCs/150,000 analyzed events by MFC can potentially upstage the R-ISS classification of a subset of NDMM pts with stage I and II disease and identify those pts with a worse than expected survival outcome.[Table: see text]

8011 Background: Literature suggests that three or more organ involvement is a contraindication for autologous stem cell transplant (ASCT) in light chain amyloidosis (AL). Most centers limit transplantation to patients who have no more than two organs significantly involved. Methods: We retrospectively reviewed all patients with AL Amyloidosis involving three or more organs and who had ASCT between 1996-2015 at Mayo clinic, Rochester, Minnesota. Results: Seventy five patients underwent ASCT with three or more organs involved. Median age at diagnosis was 54 years and 67% were males. The heart was involved in 95%, followed by kidneys (84%). Thirty eight patients (51%) had no induction treatment prior to ASCT. Full dose melphalan (200mg/m2) was given in 45%, and the remaining received a reduced dose (140mg/m2). Overall response rate (hematological) was 75%. The median progression-free (PFS) and overall survival (OS) were 16.3 and 68.9 months, respectively. The 100-day mortality was 16% and overall forty four patients (59%) died during the follow up period. The most common causes of death were cardiovascular events (32%) and progressive amyloidosis (25%). On multivariable analysis, predictors for PFS were Mayo stage III/IV (RR 3.3, P = 0.0012) and hematological response (≥VGPR, RR 0.4, P = 0.012). An NT-ProBNP level of ≥2000 pg/ml was an independent predictor for shorter PFS (RR 2.6, P = 0.013). Predictors for OS included any hematological response (RR 0.1, P < 0.0001) and Mayo stage III/IV (RR 7, P < 0.0001). When looking at the NT-ProBNP, a level ≥2000 was prognostic (RR 5.5, P = 0.001). Number of organs involved (3 vs. 4-5) was not significant in either PFS or OS. Conclusions: We conclude that the high prevalence of cardiac involvement is the main driver for the poor outcome in patients who have three or more organs involved. Using selection criteria defined for safe transplantation in cardiac amyloidosis should result in low therapy-related mortality independent of the number of organs involved. The concept of considering patients with three organs involved ineligible for stem cell transplantation should be abandoned.