Leung, Nelson

AbstractHigh‐dose methotrexate (HDMTX) pharmacokinetics (PKs), including the best estimated glomerular filtration rate (eGFR) equation that reflects methotrexate (MTX) clearance, requires investigation. This prospective, observational, single‐center study evaluated adult patients with lymphoma treated with HDMTX. Samples were collected at predefined time points up to 96 h postinfusion. MTX and 7‐hydroxy‐MTX PKs were estimated by standard noncompartmental analysis. Linear regression determined which serum creatinine‐ or cystatin C‐based eGFR equation best predicted MTX clearance. The 80 included patients had a median (interquartile range [IQR]) age of 68.6 years (IQR 59.2–75.6), 54 (67.5%) were men, and 74 (92.5%) were White. The median (IQR) dose of MTX was 7.6 (IQR 4.8–11.3) grams. Median clearance was similar across three dosing levels at 4.5–5.6 L/h and was consistent with linear PKs. Liver function, weight, age, sex, concomitant chemotherapy, and number of previous MTX doses did not impact clearance. MTX area under the curve (AUC) values varied over a fourfold range and appeared to increase in proportion to the dose. The eGFRcys (ml/min) equation most closely correlated with MTX clearance in both the entire cohort and after excluding outlier MTX clearance values (r = 0.31 and 0.51, respectively). HDMTX as a 4‐h infusion displays high interpatient pharmacokinetic variability. Population PK modeling to optimize MTX AUC attainment requires further evaluation. The cystatin C‐based eGFR equation most closely estimated MTX clearance and should be investigated for dosing and monitoring in adults requiring MTX as part of lymphoma management.

Abstract Multiple myeloma (MM) is a heterogeneous disease that may be evaluated by a broad array of imaging and laboratory techniques to measure disease activity and predict prognosis. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning has been shown to be predictive of patient outcomes throughout the disease course. We sought to corroborate these findings by examining the prognostic impact of PET/CT scanning in the posttransplant setting. We retrospectively analyzed PET/CT scans in 229 MM patients receiving an autologous stem cell transplant (ASCT) near day 100, and correlated these findings with time to progression(TTP) and overall survival (OS) to assess the impact of day 100 PET/CT scan findings as an independent prognostic factor. The median OS for the entire cohort was 61.5 months (95% confidence interval [CI], 49-75) and the median TTP was 18.5 months (95% CI, 15.4-21.8). Among patients with abnormal day 100 PET findings (PET+), median TTP was 12.4 months vs 24 months among those with normal PET findings (PET−) (P < .0001). The median OS in the PET+ group was 46 months compared with 99 months in the PET− group (P < .0001). We conclude that an abnormal PET/CT scan near day 100 post-ASCT is predictive of shorter TTP and OS, with prognostic significance retained after adjusting for disease response and other prognostic variables in MM.

AbstractMultiple myeloma (MM) remains an incurable disease despite incorporation of novel agents. Venetoclax, a B‐cell lymphoma 2 (BCL‐2) inhibitor is approved for some hematologic malignancies but not yet for MM, although clinical trials have shown efficacy in patients with MM, particularly those harboring t(11;14). We reviewed the medical records of relapsed and/or refractory MM patients to study the efficacy and safety of venetoclax used outside of clinical trials at Mayo Clinic between December, 2016 and March, 2019. The data cut‐off date was August 06, 2020. We identified 56 patients of whom 42 (75%) harbored t(11;14). The median number of prior therapies was six (range 1–15) and 14% of patients had received ≥10 prior lines of therapy. Fifty‐three (95%) patients were refractory to an immunomodulatory drug and proteasome inhibitor. Venetoclax was used as monotherapy or doublet, in combination with dexamethasone in 55% (n = 31) and a triplet or quadruplet in 45% of patients. No patient experienced tumor lysis syndrome. Overall response rate in 52 evaluable patients was 44%. The median time to best response was 2 months and median duration of response was 13.6 months. The median PFS for the entire cohort was 5.8 (95% CI 4.9–10.3) months and median OS was 28.4 (95% CI 14.6‐not reached) months. The presence of t(11;14) was associated with improved PFS (median 9.7 months vs. 4.2 months, p = 0.019) and OS (median not reached vs. 10.8 9 months, p = 0.015). Venetoclax demonstrates encouraging activity in heavily‐treated patients with relapsed/refractory MM, particularly the t(11;14) patient‐population.

Significance Statement Treatment of proliferative GN with monoclonal Ig deposition (PGNMID), in which direct deposition of the monoclonal proteins damages the kidney, is not established. Daratumumab, a monoclonal anti-CD38 antibody, has shown effectiveness as multiple myeloma therapy. In an open-label, phase 2 study, the authors evaluated safety and efficacy of a 6-month course of intravenous daratumumab in 11 patients with PGNMID and one with C3 glomerulopathy with monoclonal gammopathy. Five episodes of serious adverse events (two of which were infection related) occurred. All ten patients with PGNMID who received at least one daratumumab dose experienced a significant reduction in proteinuria at 6 months, which was sustained in seven patients by 12 months. Overall, in this pilot study, daratumumab’s acceptable toxicity profile and significant improvement in proteinuria, while stabilizing kidney function, suggest further investigation is warranted. Background Treatment of proliferative GN with monoclonal Ig deposits (PGNMID) is not established. A monoclonal anti-CD38 antibody (daratumumab) is effective in treating multiple myeloma. Abnormal plasma cell clones may play a role in the pathogenesis of PGNMID. Methods We evaluated daratumumab’s safety and efficacy in an open-label, phase 2 trial in 11 adults with PGNMID and one with C3 glomerulopathy (C3G) with monoclonal gammopathy. Patients had an eGFR >20 ml/min per 1.73 m 2 and proteinuria >1 g/d. They received daratumumab intravenously (16 mg/kg) once weekly for 8 weeks, and then every other week for eight additional doses. Primary outcome was safety, defined as major infections, grade 3 or 4 anemia, leukopenia, or thrombocytopenia. Secondary outcomes were rate of complete remission (proteinuria <500 mg/d with <15% decline in baseline eGFR) or partial remission (>50% reduction in 24-hour proteinuria with <30% decline in eGFR) and proteinuria at 6 and 12 months. Results One patient with C3G had GN unrelated to the monoclonal gammopathy, and one with PGNMID did not complete the first infusion. Five serious adverse events occurred. During the 12 months of the trial, six of the ten patients with PGNMID who received at least one dose of daratumumab had a partial response, and four had a complete response (an overall response rate of 100%). Three patients experienced relapse, two of whom re-entered partial remission after resuming daratumumab therapy. Proteinuria declined significantly, from a median of 4346 mg/d to 1264 mg/d by 12 months. Conclusions Daratumumab demonstrated an acceptable safety profile and resulted in significant improvement in proteinuria while stabilizing kidney function in patients with PGNMID, suggesting the drug merits further investigation. Clinical Trial registry name and registration number: Daratumumab in Treatment of PGNMID and C3 GN, NCT03095118

AbstractThree sets of criteria (International Society of Amyloidosis [ISA], Palladini and Kastritis) were independently developed for staging, progression and response criteria to predict renal survival in patients with AL amyloidosis. We evaluated these criteria using a cohort of 495 newly diagnosed AL amyloidosis patients with renal involvement using time to event competing risk analysis at baseline, 3, 6 and 12 months after treatment. Only Palladini and Kastritis had a staging system and both predicted a higher risk of end stage renal disease (ESRD) in the stage III vs stage I patients but only the Palladini model was predictive for stage II patients. At 3 months, risk of ESRD was significantly higher for Palladini and ISA renal progression (hazard ratio [HR] 2.8 [95% CI: 1.5–5.3, p = .001] and 2.5 [CI: 1.4–4.6, p = .004, respectively]), but renal response was not significantly protective; conversely, the risk of ESRD was not significantly higher for the Kastritis renal progression, but was significantly protective for the Kastritis renal responders (HR 0.38 [95% CI: 0.17–0.84], p = .017). Both progression and response with ISA, Palladini and Kastritis criteria were predictive of ESRD at 6 months and 12 months. While the Palladini staging criteria at baseline, and the ISA and Palladini criteria for progression at 3 months performed better than the Kastritis criteria at baseline and 3 months post‐treatment, the Kastritis criteria performed better for response 3 months after treatment. All three sets of criteria performed well at and after 6 months post‐treatment. These differences are important when choosing endpoints for clinical trials.

AbstractInduction therapy for multiple myeloma with bortezomib (Velcade), lenalidomide (Revlimid), and dexamethasone (d) (VRd) was traditionally administered as bortezomib given twice weekly on a 3 week cycle. A modified schedule of weekly bortezomib has been adopted over time to decrease treatment burden for patients and reduce treatment‐emergent neuropathy. This study evaluates the response rates and outcomes with different schedules of bortezomib in VRd administered for first‐line treatment for patients with newly diagnosed MM (NDMM). We retrospectively analyzed patients treated with upfront VRd from June 30th 2008 to December 31st 2018, for variations of bortezomib administration. Five hundred and fifty‐five (555) NDMM patients met inclusion criteria; median age 63 years and 61% men. Bortezomib was administered twice weekly every 21 days in 43%, once weekly every 21 days in 41% and once weekly every 28 days in 16%. Though peripheral sensory neuropathy was more frequent with twice weekly dosing (P = .002), this group achieved shorter time to best response (P = .01). Weekly every 21‐day treatment saw higher VGPR or better rates (P = .02). However, with median follow up time of 37 months (IQR 22–56), we found no difference in PFS or OS among the groups. While small differences in response rates were found among the varying administration schedules of bortezomib administration, there was no significant effect on PFS or OS. Given that VRd remains a first line standard of care option for newly diagnosed MM, in the absence of a large trial comparing bortezomib dosing schedule modifications, these results are helpful in supporting current practices of once weekly administration.

SummaryMeasurable residual disease (MRD) assessment by marrow‐based next‐generation flow cytometry (NGF) following autologous stem cell transplantation (ASCT) may lead to false‐negative results due to patchy marrow involvement and extramedullary disease in patients with multiple myeloma. We assessed the value of simultaneous MRD evaluation with NGF and serum matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MASS‐FIX). Of all 61 complete responders who were NGF‐negative for MRD, around day‐100 post ASCT, 59% were MASS‐FIX‐positive. At median follow‐up of 26 months, 69% of MASS‐FIX(+)/NGF(−) patients were alive and progression‐free versus 96% of MASS‐FIX(‐)/NGF(−) patients, P = 0·02. MASS‐FIX, a simple peripheral blood‐based assay complements marrow‐based NGF to accurately prognosticate patients with myeloma.