PURPOSE Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI). METHODS This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes. RESULTS Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses. CONCLUSION In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.
P540 Non-serious adverse events in patients with ulcerative colitis receiving etrasimod: An analysis of the phase 2 OASIS and phase 3 ELEVATE UC 52 and ELEVATE UC 12 clinical trials
Abstract Background Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis (UC). Adverse events (AEs) pertaining to tolerability, laboratory and serious AEs are described elsewhere1,2; we present a post hoc analysis of the incidence, onset and duration of the most commonly occurring non-serious AEs in the etrasimod UC clinical programme. Methods Data from the pooled Placebo-controlled UC cohort, derived from the phase 2 OASIS (NCT02447302) and phase 3 ELEVATE UC 52 (NCT03945188) and ELEVATE UC 12 (NCT03996369) double-blind clinical trials, were included. Cohorts comprised OASIS and ELEVATE UC 12 12-week induction periods alongside the ELEVATE UC 52 12-week induction and 40-week maintenance periods utilising a "treat-through" design. Patients (pts) with moderately to severely active UC were eligible for the etrasimod UC clinical programme. Pts were randomised to etrasimod 1 mg once daily (QD; OASIS only), etrasimod 2 mg QD or placebo. Proportions and incidence rates (IRs) of non-serious AEs (MedDRA v24.1 Preferred Terms of headache, pyrexia, nausea, fatigue and dizziness) were analysed in the Placebo-controlled UC cohort. Results Among 943 pts (any dose of etrasimod, N=629 [288.1 pt years (PY)]; placebo, N=314 [115.1 PY]), there were 77, 36, 30, 15 and 23 headache, pyrexia, nausea, fatigue and dizziness AEs, respectively. All were non-serious and did not lead to treatment discontinuation, apart from one case of pyrexia in which early termination visits were incomplete. Proportions and IRs (per 100 PY) for headache and dizziness AEs were higher with etrasimod (any dose) vs placebo (IRs: 13.45 vs 8.63 and 6.52 vs 1.69, respectively); IRs for other non-serious AEs were similar in etrasimod (any dose) and placebo groups (Table). Onset of AEs varied over time and most AEs were short in duration (Figure shows onset and duration for headache and dizziness AEs). Most AEs were deemed not related to study treatment by the site investigator. Pts with dizziness on Days 1–3 had similar changes in heart rate vs those with dizziness after Day 3. No consistent trend in heart rate was observed in pts receiving etrasimod with early dizziness. Conclusion Among pts in the etrasimod UC clinical programme, all headache, pyrexia, nausea, fatigue and dizziness events were non-serious. IRs were similar for most non-serious AEs across treatment groups, excluding headache and dizziness. Most non-serious AEs were short in duration and judged as not related to study treatment, suggesting they may not impact on the overall tolerability of etrasimod. References 1. Sandborn WJ et al. Gastroenterology 2020; 158: 550–61. 2. Sandborn WJ et al. Lancet 2023; 401: 1159–71.
PF484 MARKERS ASSOCIATED WITH SHORT SURVIVAL IN PATIENTS WITH WALDENSTRÖM MACROGLOBULINEMIA
Background:Waldenström Macroglobulinemia (WM) is a rare, indolent B‐cell lymphoplasmacytic malignancy. Patient outcomes are highly heterogeneous, with a proportion of patients surviving less than 5 years (short survivors) and another proportion that survive longer than 10 years. The laboratory parameters in the currently used International Prognostic Scoring System for WM (IPSSWM) include hemoglobin, serum IgM, platelet count, and serum β2‐microglobulin.Aims:We aim to identify unique patient characteristics and prognostic features associated with short survival in WM.Methods:The medical records of patients with active WM that were diagnosed at Mayo Clinic Rochester, Arizona, and Florida between January 1st, 1996 and December 31st, 2013 were reviewed. The patients with smoldering WM were excluded. Cohorts of patients who either survived ≤ 5 years (Short Survival Group) or those with an overall survival (OS) ≥ 10 years (Long Survival Group) from the diagnosis of active disease were compared. Survivors with a follow‐up of ≤ 5 years were not included in the analyses. Two‐sided Wilcoxon rank sum test and Chi square/Fisher's exact test were used to compare the continuous and categorical variables, respectively. The variables that were statistically significant on univariate analysis (P < 0.05) were included in a multivariate logisitic regression analysis.Results:Of 893 consecutively seen WM patients (median follow‐up of 9 years [95% CI 8.4–9.7]), we identified 387 patients who could be categorized into either the Short Survival Group (n = 171 patients, 44%) or the Long Survival Group (n = 216, 56%). The Short Survival Group had a median OS of 2.4 years (2.1–2.8) and median age at diagnosis of 73 years (42–93), while the Long Survival Group (n = 216, 56%) had a median OS of 18.9 years (16‐NR) and median age at diagnosis of 62 years (31–85). The baseline characteristics and significant findings between the two groups are listed in the Table. Parameters significant on univariate analysis included age >65 years, albumin < 3.5 g/dL, β2‐microglobulin >3 μg/ml, and LDH > upper limit of normal (ULN). On multivariate analysis, albumin <3.5 g/dL and LDH > ULN were independently associated with short survival. Among the Long Survivors, 60 (28%) patients survived 15 years or more.Summary/Conclusion:Lactate dehydrogenase above the ULN and serum albumin <3.5 g/dL are independent biomarkers of short survival in WM. The MYD88 L265P status and the size of serum IgM are not prognostic in WM. Our data suggest the need for simplification of the current staging system with the use of widely available markers: serum albumin and lactate dehydrogenase.image
Background: Most older patients (pts) with relapsed or refractory (R/R) AML cannot tolerate intensive treatment and are not eligible for curative allogeneic hematopoietic cell transplant (alloHCT). 131I-apamistamab, an anti-CD45 radioimmunoconjugate, delivers high dose targeted radiation to hematopoietic cells, allowing for myeloablation and eradication of leukemic cells. 131I-apamistamab led induction and conditioning can provide these pts with access to alloHCT. Methods: SIERRA (NCT02665065) was a multi-center, randomized, controlled phase 3 study comparing the efficacy of 131I-apamistamab led induction and conditioning versus physician's choice of conventional care (CC) in pts ≥55 years of age with active, R/R AML. Pts were randomized (1:1, n=153) to CC or 131I-apamistamab with fludarabine and total body irradiation (2 Gy) followed by alloHCT. Primary endpoint was durable complete remission (dCR), defined as CR ≥6 mos with or without platelet recovery (CRp). Pts not achieving CR in CC could crossover (CO) to receive 131I-apamistamab. Treatment with 131I-apamistamab was prescribed as an individualized dose for each pt following a dosimetric infusion and biodistribution analysis, with the prescribed activity of 131I set to deliver a maximum estimated radiation dose to the liver as the dose limiting organ of 24 Gy (determined as the maximum tolerable dose (MTD)) in earlier studies), thereby providing the highest dose to the diseased bone marrow and circulating leukemic cells without exceeding individual organ radiation dose tolerances. Here, we performed an analysis to determine whether a radiation dose-response relationship could be established based on either 1) administered radiation dose to liver and the rate of achieving the primary endpoint of dCR (with 95% binomial confidence intervals) or 2) dCR rate and the ratio of bone marrow/liver absorbed radiation dose as an indicator of favorable biodistribution between target/risk organ. Results: All pts receiving the therapeutic dose of 131I-apamistamab (n=66) were able to receive an alloHCT, and the primary endpoint (dCR) was achieved in 13 pts receiving 131I-apamistamab vs 0 pts in CC (p<0.0001). The median absorbed liver dose was 21.6 Gy (IQR: 21.0 - 22.8 Gy), median absorbed dose to bone marrow was 16.0 Gy (IQR: 11.5 - 22.3 Gy), and median ratio between marrow/liver dose was 0.79 (IQR: 0.52 - 1.02). Table 1 shows the distribution and rate of dCR for pts who received above or below 22 Gy administered dose to liver (24 Gy to liver was the established MTD from earlier studies, in which doses were escalated in 2 Gy increment and thus, 22 Gy represented MTD-1), and for pts stratified by marrow/liver dose ratio (higher ratio representing more favorable biodistribution). Pts with ≤22 Gy liver dose had a dCR rate of 13.5% vs. 27.6% for pts with >22 Gy liver dose, and pts with <median dose to bone marrow had a dCR rate of 12.1% vs. 27.3% for pts with ≥median estimated marrow dose. Importantly, pts with increasingly favorable biodistribution had nominally higher dCR rates of 10.0%, 20.0% and 26.9% for a marrow/liver ratio <0.6, 0.6-0.9 and >0.9, respectively, as illustrated in Figure 1. Taken together this demonstrates a radiation dose-response for the primary endpoint in this study. Overall, safety was similar across doses to the liver. Conclusion: 131I-apamistamab led induction and conditioning followed by alloHCT resulted in statistically significant improvement in dCR at 6 mos vs conventional care. A dose-response was demonstrated for pts receiving 131I-apamistamab with those receiving a liver dose closer to the MTD of 24 Gy having about twice the dCR rate compared to pts 22 Gy (MTD-1) or less. We also found pts with higher marrow/liver ratio experienced considerably higher rates of dCR which highlights the importance of maximizing the dose to target tissues, within the limits of established risk organ dose tolerances.
ELISA-Negative Platelet-Activating Anti-PF4 Antibodies Can Cause HIT and Monoclonal Gammopathy of Thrombotic Significance (MGTS)
We identified a patient with a recently described syndrome, monoclonal gammopathy of thrombotic significance (MGTS; Blood. 2023 Apr 6;141(14):1772-1776), and three additional patients with high 4Ts scores who were consistently negative in the PF4-polyanion HIT ELISA (Lifecodes PF4 IgG, Immucor). The MGTS patient, with a monoclonal IgG kappa, had recurrent thrombosis, and transient mild thrombocytopenia (nadir in the low 100s) over a period of years, and was noted to have a HIT ELISA optical density (OD) of 0.117. The three HIT patients experienced thrombocytopenia and thrombosis with ELISA ODs of 0.37, 0.18 and 0.20. All patients were positive in platelet-activation (functional) testing demonstrating PF4 dependence and inhibited with both high concentrations of heparin (100U/mL) and the FcγRIIa blocking monoclonal antibody (mAb) IV.3, consistent with the presence of anti-PF4 antibodies in the patient samples ( data not shown). Because the serologic profile of these patients suggested a novel HIT subtype characterized by negative HIT ELISA results, we undertook a functional platelet assay screen of 500 consecutive HIT ELISA-negative patients tested in our diagnostic laboratory. Research studies were approved by the Institutional Review Board of Mayo Clinic. Of the 500 patients tested, 20 (4.0%) stimulated platelet activation in the PF4-dependent P-selectin Expression Assay (PEA ≥19%; data not shown). To exclude non-specific activation that can be induced by HLA antibodies, additional testing was performed to evaluate whether platelet activation was PF4-dependent using buffer or PF4-treated platelets. Three patients demonstrated PF4-dependent activation that was inhibited by high heparin concentrations and mAb IV.3, as would be expected for HIT antibodies (ELISA-negative HIT, EN-HIT1-3; Figure 1). On retrospective review, all three patients thus identified had clinical histories and courses consistent with high clinical probability for HIT. To develop tools to study this new class of antibodies, monoclonal HIT antibodies were generated in mice after PF4/heparin immunizations and screened using a novel approach that included simultaneous testing of hybridoma supernatants in the PEA and PF4-polyanion ELISA. This strategy was designed to enabled us to identify mAbs that activated platelets (in the PEA), but that did not bind antigenic targets in the HIT ELISA. A novel mAb 431.4 that was developed using this approach, and the well-characterized HIT-like mAb KKO were evaluated for their abilities to both bind PF4-polyanion targets in ELISA, and to activate PF4-treated platelets in the PEA (Figure 2). In significant contrast to KKO, mAb 431.4 did not bind PF4/polyanion complexes, however, like KKO, strongly activated platelets in a PF4-dependent manner. Activation induced by both KKO and mAb 431.4 was inhibited by high heparin concentrations, as would be expected for HIT antibodies. In vivo murine studies using this novel mAb are pending at this time. In summary, the non-canonical diagnostic profile of HIT ELISA-negative but platelet activation-positive antibodies were found at a relatively high incidence in HIT-suspected patients (0.6%; 3 of 500 ELISA-negative patients). These findings have important diagnostic/management implications and suggest a re-evaluation of ASH's HIT management guidelines as noted in recommendations 2.7 and 2.8 of that document (“In patients with an intermediate (Recommendation 2.7) or high (Recommendation 2.8)-probability 4Ts score and a negative immunoassay, the ASH guideline panel recommends discontinuation of the non-heparin anticoagulant and resumption of heparin, if indicated ”; Blood Adv (2018) 2 (22): 3360-3392). Figure 1. A subset of ELISA-negative HIT-suspected patients harbor anti-PF4 platelet-activating antibodies. Three ELISA-negative (EN) HIT patient samples from a screen of 500 samples demonstrate PF4-dependent platelet activation and inhibition with high heparin concentration and mAb IV.3 incubation. PBS, phosphate buffered saline; IC, isotype control; HDH- high dose heparin (100U/mL). Figure 2. Murine mAb 431.4 serologically mimics pathogenic ELISA-negative HIT/MGTS antibodies. ELISA and PEA testing was performed using the “HIT-like” mAb KKO, novel mAb 431.4, or an isotype control (IC) antibody. PVS-polyvinyl sulfonate (polyanion used in the Immucor IgG ELISA assay).
Impact of sex on antidepressant discontinuation in groups of similar cytochrome P450 phenotypes
Abstract Introduction Although there are studies assessing reasons for antidepressant discontinuation, little is known about the impact of sex differences or cytochrome P450 phenotypes. Our objective is to assess discontinuation rates between males and females and whether CYP450 phenotype influences discontinuation. Methods This is a retrospective review of patients previously enrolled in the Right Drug, Right Dose, Right Time: Using Genomic Data to Individualize Treatment database with major depressive disorder. Patients were evaluated for antidepressants trialed between January 1, 2009, and September 30, 2019. Survival analyses with competing risks were used to analyze discontinuation reasons. A Kaplan-Meier estimation method was used to assess the time to discontinuation and discontinuation rates. Analyses were also completed to assess discontinuation between men and women by phenotypic groups. All tests were two-sided, and p-values ≤ .05 were considered statistically significant. Results There were 620 antidepressant discontinuation events discovered from 1015 antidepressant trials included. Overall, the median time to discontinuation for males was 2.6 years and 1.9 years for females (hazard ratio [HR] 0.97 [95% confidence interval (CI): 0.80, 1.19], p = .77). The risk of discontinuation was not different between males and females in any of the phenotype groups, which was consistent in the multivariable analyses. Concomitant use of medications that inhibited or induced antidepressant metabolism increased the overall risk of discontinuation (HR 1.45, 95% CI [1.06, 1.99], p = .020) in a time-dependent analysis. Discussion We did not detect a significant difference in risk of antidepressant discontinuation rates between males and females even when accounting for cytochrome P450 phenotype. Future studies should account for whether medications that inhibit or induce antidepressant metabolism may be a crucial factor in antidepressant discontinuation.
Risk model‐based management for second primary lung cancer among lung cancer survivors through a validated risk prediction model
AbstractBackgroundRecent therapeutic advances and screening technologies have improved survival among patients with lung cancer, who are now at high risk of developing second primary lung cancer (SPLC). Recently, an SPLC risk‐prediction model (called SPLC‐RAT) was developed and validated using data from population‐based epidemiological cohorts and clinical trials, but real‐world validation has been lacking. The predictive performance of SPLC‐RAT was evaluated in a hospital‐based cohort of lung cancer survivors.MethodsThe authors analyzed data from 8448 ever‐smoking patients diagnosed with initial primary lung cancer (IPLC) in 1997–2006 at Mayo Clinic, with each patient followed for SPLC through 2018. The predictive performance of SPLC‐RAT and further explored the potential of improving SPLC detection through risk model‐based surveillance using SPLC‐RAT versus existing clinical surveillance guidelines.ResultsOf 8448 IPLC patients, 483 (5.7%) developed SPLC over 26,470 person‐years. The application of SPLC‐RAT showed high discrimination area under the receiver operating characteristics curve: 0.81). When the cohort was stratified by a 10‐year risk threshold of ≥5.6% (i.e., 80th percentile from the SPLC‐RAT development cohort), the observed SPLC incidence was significantly elevated in the high‐risk versus low‐risk subgroup (13.1% vs. 1.1%, p < 1 × 10–6). The risk‐based surveillance through SPLC‐RAT (≥5.6% threshold) outperformed the National Comprehensive Cancer Network guidelines with higher sensitivity (86.4% vs. 79.4%) and specificity (38.9% vs. 30.4%) and required 20% fewer computed tomography follow‐ups needed to detect one SPLC (162 vs. 202).ConclusionIn a large, hospital‐based cohort, the authors validated the predictive performance of SPLC‐RAT in identifying high‐risk survivors of SPLC and showed its potential to improve SPLC detection through risk‐based surveillance.Plain Language Summary Lung cancer survivors have a high risk of developing second primary lung cancer (SPLC). However, no evidence‐based guidelines for SPLC surveillance are available for lung cancer survivors. Recently, an SPLC risk‐prediction model was developed and validated using data from population‐based epidemiological cohorts and clinical trials, but real‐world validation has been lacking. Using a large, real‐world cohort of lung cancer survivors, we showed the high predictive accuracy and risk‐stratification ability of the SPLC risk‐prediction model. Furthermore, we demonstrated the potential to enhance efficiency in detecting SPLC using risk model‐based surveillance strategies compared to the existing consensus‐based clinical guidelines, including the National Comprehensive Cancer Network.