Dose Of High-dose Methotrexate Research Articles

Low-Dose Planned Glucarpidase Allows Safe Outpatient High-Dose Methotrexate Treatment for CNS Lymphoma.

High-dose methotrexate (HD-MTX) is the backbone of curative therapy for CNS lymphoma. Because of toxicity, MTX is administered in the inpatient setting along with hyperhydration and monitoring until MTX clearance is documented (3-5 days). Frequent hospitalizations result in patient time away from work, home, and exposure to potential iatrogenic/nosocomial complications. Here, we aim to demonstrate feasibility of HD-MTX administration in the outpatient setting with low-dose glucarpidase facilitating clearance. This is a prospective nonrandomized study of outpatient HD-MTX followed by glucarpidase 2000u (ClinicalTrials.gov identifier: NCT03684980). Eligible patients had CNS lymphoma, creatinine <1.3 mg/dL, and previously tolerated HD-MTX. Patients were enrolled between May 2020 December 2021 for one HD-MTX treatment. Patients could re-enroll for subsequent doses of HD-MTX as eligibility and slots permitted. MTX 3.5 g/m2 was administered once over 2 hours, preceded by standard hydration and followed by an additional 2 hours of dextrose 5% in water with NaHCO3 75 mEq at 150 cc/h. Glucarpidase 2000u was administered once in the clinic 24 hours later. The primary end point was MTX level 48 hours after HD-MTX. Twenty doses of outpatient HD-MTX with glucarpidase were administered to seven patients. After 20 of 20 (100%) treatments, serum MTX levels were reduced to <100 nmol/L. Treatments were well-tolerated, and no admissions were required. One patient received additional outpatient hydration for elevated creatinine. Development of antiglucarpidase antibody was rare and did not affect treatment. Outpatient HD-MTX with glucarpidase is safe and well-tolerated and has the potential to alter standard treatment for CNS lymphoma.

Development and validation of a model to predict acute kidney injury following high-dose methotrexate in patients with lymphoma.

To develop and validate a model for predicting acute kidney injury (AKI) after high-dose methotrexate (HDMTX) exposure. Retrospective analysis. Multisite integrated health system throughout Minnesota and Wisconsin. Adult patients with lymphoma who received HDMTX as a 4-h infusion. LASSO methodology was used to identify factors available at the outset of therapy that predicted incident AKI within 7 days following HDMTX. The model was then validated in an independent cohort. The incidence of AKI within 7 days following HDMTX was 21.6% (95% confidence interval (CI) 18.4%-24.8%) in the derivation cohort (435 unique patients who received a total of 1642 doses of HDMTX) and 15.6% (95% CI 5.3%-24.8%) in the validation cohort (55 unique patients who received a total of 247 doses of HDMTX). Factors significantly associated with AKI after HDMTX in the multivariable model included age ≥ 55 years, male sex, and lower HDMTX dose number. Other factors that were not found to be significantly associated with AKI on multivariable analysis, but were included in the final model, were body surface area, Charlson Comorbidity Index, and estimated glomerular filtration rate. The c-statistic of the model was 0.72 (95% CI 0.69-0.75) in the derivation cohort and 0.72 (95% CI 0.60-0.84) in the validation cohort. This model utilizing identified sociodemographic and clinical factors is predictive of AKI following HDMTX administration in adult patients with lymphoma.

A Systematic Review of High-Dose Methotrexate for Adults with Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin lymphoma that is confined within the CNS. Due to its ability to cross the blood-brain barrier, high-dose methotrexate (HDMTX) is the backbone for induction chemotherapy. This systematic review was conducted to observe outcomes among different HDMTX doses (low, <3 g/m2; intermediate, 3-4.9 g/m2; high, ≥5 g/m2) and regimens used in the treatment of PCNSL. A PubMed search resulted in 26 articles reporting clinical trials using HDMTX for PCNSL, from which 35 treatment cohorts were identified for analysis. The median dose of HDMTX used for induction was 3.5 g/m2 (interquartile range IQR, 3-3.5); the intermediate dose was most frequently used in the studies examined (24 cohorts, 69%). Five cohorts used HDMTX monotherapy, 19 cohorts used HDMTX + polychemotherapy, and 11 cohorts used HDMTX + rituximab ± polychemotherapy. Pooled overall response rate (ORR) estimates for low, intermediate, and high dose HDMTX cohorts were 71%, 76%, and 76%, respectively. Pooled 2-year progression-free survival (PFS) estimates for low, intermediate, and high HDMTX dose cohorts were 50%, 51%, and 55%, respectively. Regimens that included rituximab showed a tendency to have higher ORR and 2-year PFS than those that did not include rituximab. These findings indicate that current protocols utilizing 3-4 g/m2 of HDMTX in combination with rituximab provide therapeutic efficacy in PCNSL.

Is more better? Increased doses of high dose methotrexate and addition of rituximab is associated with improved outcomes in a large primary CNS lymphoma cohort.

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive primary brain tumor. While high dose methotrexate (HDMTX) regimens remain standard of care, it remains unclear if optimization of HDMTX doses and the addition of rituximab provide clinical benefit. Over the last 30 years, standard care given at Memorial Sloan Kettering Cancer Center (MSKCC) has evolved, allowing the comparison of patients receiving different numbers of HDMTX doses and those treated with and without rituximab. The purpose of this study was to describe outcomes based on treatment pattern changes. This single-center, retrospective, IRB-approved study at MSKCC included patients with immunocompetent PCNSL, age ≥18 years and diagnosed between 1/1983-12/2017. Overall survival (OS) was modeled from date of last HDMTX for analyses associating HDMTX and OS. Multivariable Cox regression models estimated hazard ratios (HR) and corresponding 95% confidence intervals (CI). There were 546 patients identified with newly diagnosed PCNSL. Median overall survival (mOS) of the entire population was 4.7 years (95% CI: 3.8-5.7 years); 3.3 years (95% CI: 2.7-3.9 years) in patients diagnosed prior to 2006 and 8.1 years (95% CI: 6.6-11.1 years) in patients diagnosed 2006 onwards. Patients receiving ≥6 doses of HDMTX had improved survival compared to those receiving <6 doses of HDMTX (mOS: 7.8 vs. 4.3 years; P=0.001). Patients receiving induction rituximab had improved OS compared to those who did not receive rituximab (mOS: 10.5 vs. 3.2 years; P<0.0001). Patients receiving ≥6 doses of HDMTX and rituximab had greatest mOS at 13 years, with a 70% reduction in death (HR =0.30; 95% CI: 0.19-0.47) adjusting for treatment era, sex, and recursive partitioning analysis (RPA) classes comprising age and karnofsky performance score (KPS). OS for PCNSL has improved significantly over the last few decades. Patients seem to benefit with ≥6 doses of HDMTX and the addition of rituximab, an effect independent of treatment era, age, and KPS.

A prospective cohort study of methotrexate plus idarubicin in newly diagnosed primary CNS lymphoma.

High-dose methotrexate (HD-MTX)-based chemotherapy regimen is the first-line option for primary central nervous system lymphoma (PCNSL). This prospective cohort study aimed to evaluate the efficacy and adverse effects of HD-MTX plus idarubicin (IDA) in patients with newly diagnosed immunocompetent PCNSL. We recruited newly diagnosed PCNSL patients from January 2017 to August 2020. Patients were assigned into two groups: HD-MTX monotherapy and HD-MTX plus IDA (HD-MTX/IDA). In the HD-MTX monotherapy group, patients were treated with MTX 8g/m2 alone on day 1, while the HD-MTX/IDA group received MTX 8g/m2 on day 1 and IDA 10mg/m2 on day 2. Treatments were repeated every 3weeks for 8 cycles except for progression and/or unacceptable toxicity. We recruited 61 PCNSL patients, including 36 in the HD-MTX and 25 in the HD-MTX/IDA group. The CR rate was 68% in the HD-MTX/IDA group and 72.22% of patients in the HD-MTX monotherapy group (p = 0.7221), while the overall response rate was 72% vs. 77.78% (p = 0.6063). Median PFS in HD-MTX/IDA group and HD-MTX monotherapy group were 15.6months and 18.5months, respectively (p = 0.6374). Median OS was not reached in both groups. There were no significant differences in adverse effects between the two groups. The combination of IDA with HD-MTX showed no obvious therapeutic advantage over HD-MTX monotherapy in newly diagnosed patients with PCNSL. HD-MTX dose of 8g/m2 monotherapy can still provide better therapeutic benefits in patients with acceptable adverse effects. Future studies could explore HD-MTX in combination with other chemotherapeutic agents in the first-line treatment of PCNSL.

High-dose methotrexate and rituximab induction regimen in immunocompetent patients with primary CNS lymphoma: a retrospective single-center study of survival predictors.

Primary Central Nervous System Lymphoma (PCNSL) is an aggressive tumor that is confined to the CNS. Although the provision of high-dose methotrexate (HD-MTX) has remarkably improved outcomes in PCNSL patients, the optimal treatment regimens and standard MTX dose for induction therapy have been largely controversial. Herein, we sought to explore the impact of adjuvant rituximab and different dosages of induction HD-MTX on survival outcomes of immunocompetent patients with PCNSL. In this study, we examined patients with PCNSL treated at a single NCI-designated comprehensive cancer center to evaluate their survival outcomes. We conducted a retrospective analysis of 51 immunocompetent patients with PCNSL who received their induction chemotherapy at the University of Alabama at Birmingham (UAB) between 2001 and 2019. Only adult patients with a confirmed diagnosis of PCNSL who had either HD-MTX alone or in combination with rituximab were included. Patients' demographics, clinical characteristics, and survival data were collected and analyzed. There is no significant difference in survival among patients who received MTX alone versus MTX plus rituximab (HR = 0.996 (95% CI: 0.398-2.493), p = 0.994). Lower doses of MTX were associated with worse survival outcomes (HR = 0.680 (95% CI: 0.530-0.872), p = 0.002); however, this difference in survival was not significant when adjusted to age (HR = 0.797 (95% CI: 0.584-1.088), p = 0.153). Our experience challenges the role of rituximab in PCNSL during induction therapy. Our study also highlights the shorter survival in elderly patients with PCNSL which can be related, to some extent, to the relatively lower doses of HD-MTX. There is an unmet need to establish a consensus on the most effective upfront regimen in PCNSL through prospective studies.

High-dose methotrexate dosing strategy in primary central nervous system lymphoma

The backbone induction therapy for primary central nervous system lymphoma (PCNSL) is high dose methotrexate (HD-MTX) and rituximab, which can be combined with other chemotherapeutic agents. The optimal dose of HD-MTX remains unclear, as doses between 3 and 8 g/m2 have been shown to be effective. In this retrospective study, HD-MTX dosed at 3–5 g/m2 demonstrated an overall response of 81.8%, with 11 (50%) complete responses. The median overall survival was not met at 29 months and median progression free survival was 12.5 months. There were two discontinuations due to nephrotoxicity. The most common adverse event was hepatotoxicity (18.5%), with no treatment-related mortality events observed. Overall, HD-MTX dosed at 3–5 g/m2 demonstrated similar efficacy and lower toxicity compared to higher doses in PCNSL patients. Reducing the initial HD-MTX dose may help ensure tolerability and completion of induction therapy, especially in patients with co-morbidities or older age who have poorer outcomes.

High dose methotrexate in adult Egyptian patients with hematological malignancies: impact of ABCB1 3435C > T rs1045642 and MTHFR 677C > T rs1801133 polymorphisms on toxicities and delayed elimination

High dose methotrexate (HDMTX) is an essential agent in chemotherapeutic regimens used in various hematological malignancies in Egyptian adults. The research for the impact of gene polymorphism on HDMTX induced toxicities and delayed elimination is an important ongoing objective in many studies, variable and conflicting results produced in the past years to clarify that impact. This study aimed to investigate the role of ABCB1 3435 C > T rs1045642 and MTHFR 677 C > T rs1801133 polymorphisms on HDMTX induced toxicity outcomes and delayed elimination in Egyptian adult patients with hematological malignancies. A prospective, observational cohort study was conducted on a total of 62 Egyptian adult patients with hematological malignancies age ≥ 18-years-old. All demographic, medical, and laboratory data were continuously collected from the patients’ medical files in an up-to-date follow-up in selected clinics during the period from April 2018 to March 2020. Venous blood samples were collected for the purpose of genotyping, DNA extraction, and measurement of MTX levels. All the relevant data were statistically analyzed. The studied patients' median age was 25 years old with a range of (18–62) years. Forty-six patients were males with about 74%, and 16 were females with about 26%. Eighty-nine percent of the patients diagnosed with acute lymphoblastic leukemia ‘ALL’, 5% of the patients had B cell non-hodgkin lymphoma ‘B-NHL’ and 3% diagnosed with primary central nervous system lymphoma ‘PCNSL’ and Burkitt’s lymphoma ‘BL’ Hematological, hepatic, renal and gastrointestinal toxicities observed post-HDMTX were recorded with the hematological toxicities toping on all the others, also patients with delayed elimination at 72 hours post the HDMTX dose were determined. Statistical analysis revealed a significant association between ABCB1 3435 C > T rs1045642 and HDMTX delayed elimination with about 10 times higher risk among the minor allele ‘T’ carriers (p-value = 0.006) (odds ratio [OR]: 10.470; 95% CI: 1.961–55.904). No significant association observed between the studied gene polymorphisms: MTHFR 677 C > T rs1801133, ABCB1 3435 C > T rs1045642, and different toxicity outcomes. According to our best knowledge, this study is the first to conclude a significant association between ABCB1 3435 C > T rs1045642 gene polymorphism and HDMTX delayed elimination at 72 hours post HDMTX infusion; also, it is the first study to analyze the association between ABCB1 3435 C > T rs1045642 polymorphism with HDMTX toxicity and delayed elimination in adult Egyptian patients with hematological malignancies.

A single assessment of methotrexate levels at 42 hours permits safe administration and early discharge in children with lymphoblastic lymphoma and leukemia receiving high-dose methotrexate

High-dose methotrexate (HDMTX) is an important component of treatment in pediatric acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LL). Optimal rescue therapy is essential for the safe administration of HDMTX. A cost-effective strategy that does not compromise safety is necessary for low- and middle-income countries. Consecutive admissions for HDMTX in children with ALL and LL over 12 months were analyzed. The dose of HDMTX was 3 g/m2 in B-ALL and B-LL and 5 g/m2 in T-ALL and T-LL. A methotrexate level was measured at 42 hours of starting HDMTX infusion (T42-MTX). Three doses of folinic acid at T42, T48, and T54 and alkalinized hydration till T54 were administered if T42-MTX <1 µM. A total of 282 cycles of HDMTX that were administered in 71 patients were analyzed. T42-MTX was <1 µM in 266 (94.3%) cycles. T42-MTX was ≥1 µM in 12% and 3% of cycles of HDMTX administered at a dose of 5 g/m2 and 3 g/m2, respectively (p = .074). The median duration of hospitalization for HDM was three days and did not differ with the dose of HDMTX administered (p = .427). Mucositis, delayed recovery of blood counts, and hospitalization for reversible toxicity occurred after 21 (7.4%), 28 (9.9%), and 19 (6.7%) cycles of HDMTX, respectively. Mucositis was greater following the administration of 5 g/m2 of HDMTX. A single T42-MTX measurement permits the safe administration of HDMTX and an expedited discharge from the hospital within three days in more than 90% of children with ALL/LL.

Lack of drug interaction between levetiracetam and high-dose methotrexate in patients with lymphoma.

To determine whether there is a drug-drug interaction precluding the concomitant use of levetiracetam and high-dose methotrexate (HDMTX). Retrospective analysis. Large academic tertiary care medical center. Adult lymphoma patients who received HDMTX as a 4-h infusion with or without concomitant levetiracetam. Generalized estimating equations clustered on patient were used to assess each outcome. The primary outcome was the incidence of delayed MTX elimination (MTX level >1 µmol/L at 48 h). Secondary outcomes included incidence of acute kidney injury (AKI) and hospital length of stay (LOS). The 430 included patients receiving 1993 doses of HDMTX had a median (IQR) age of 66 (57.5, 72.6) years, 88 (20.5%) received concomitant levetiracetam with at least one dose of MTX, 267 (62.1%) were male, and 397 (92.3%) were Caucasian. HDMTX doses ranged from 1 to 8 g/m2 . The most common lymphoma diagnoses were systemic diffuse large B-cell lymphoma (DLBCL; 58.5%) and systemic DLBCL with central nervous system (CNS) involvement (32.8%). Rates of delayed elimination with and without levetiracetam were 13.4% and 16.3%, respectively (OR = 0.80, 95% CI 0.47-1.34, p = 0.39). AKI occurred in 15.6% and 17.0% of patients with and without concomitant levetiracetam, respectively (OR = 0.83, 95% CI 0.52-1.33, p = 0.28). The median LOS with and without levetiracetam was 4.2 and 4.1 days, respectively (p = 0.039). On multivariable analyses, only age, body surface area, diagnosis of systemic DLBCL with CNS involvement, serum creatinine, hemoglobin, total bilirubin, and dose of HDMTX were associated with delayed elimination. High-dose methotrexate administered with concomitant levetiracetam was not associated with increased risk for delayed MTX elimination or AKI. These results support that levetiracetam and HDMTX are safe for coadministration.

Low Serum Albumin Level Is a Risk Factor for Delayed Methotrexate Elimination in High-Dose Methotrexate Treatment.

In high-dose methotrexate (HD-MTX) therapy, delayed elimination of MTX from plasma leads to severe adverse effects. However, the risk factors for the delayed elimination of plasma MTX are still unclear. The purpose of this study was to investigate the factors related to the delayed MTX elimination in HD-MTX monotherapy. This retrospective study was performed on patients who received HD-MTX monotherapy between April 2009 and March 2019 at the Hiroshima University Hospital. Patients were divided into a "Normal" and a "Delayed" group according to their MTX plasma concentration at 48 or 72 hours after administration. Patient characteristics, dose of HD-MTX, MTX plasma concentration, and adverse effects were analyzed and compared between the 2 groups. A total of 74 patients were included in this study. Logistic analysis of patient baseline characteristics was performed to identify risk factors for delayed MTX elimination. Serum albumin (ALB) was detected as a risk factor. Univariate and multivariate analysis revealed that low ALB level (<3.7 g/dL) and type of cancer were associated with delayed MTX elimination (univariate analysis: odds ratio [OR] = 6.00, P = 0.004, and OR = 4.33, P = 0.039, respectively; multivariate analysis: adjusted OR [AOR] = 6.45, P = 0.006, and AOR = 8.11, P = 0.018, respectively). Adverse effects were not significantly different between the 2 groups, excluding renal impairment. Our study showed that low ALB is a risk factor for delayed MTX elimination in HD-MTX monotherapy. Pharmacokinetic analysis is needed to establish the dose of HD-MTX in patients with a low ALB level.

ALL-406: Comparison of Safe Delivery of 2 and 5 g/m2 of High-Dose Methotrexate to Children with Acute Lymphoblastic Leukemia in Sri Lanka without Availability of Methotrexate Levels

<h3>Context</h3> In many low- and middle-income countries (LMICs), there are barriers to delivery of chemotherapy based on international protocols. For higher-risk Acute Lymphoblastic Leukemia (ALL) in children and adolescents, most protocols mandate four courses of high-dose methotrexate (HDMTX) at 5 g/m². However, because of the risk of toxicity, many patients in LMICs receive lower doses. <h3>Design</h3> We retrospectively reviewed management and outcomes of patients treated for ALL using HDMTX (2 or 5 g/m²) as a 24-hour infusion to determine whether the higher dose had unacceptable toxicity. <h3>Setting</h3> At the National Cancer Institute Sri Lanka, delivery of HDMTX is challenging due to shortage of nurses, large numbers of patients, crowded conditions, and inability to measure methotrexate levels. Our team disagrees about the optimal dose of HDMTX, with some physicians using 2 and others 5 g/m². <h3>Patients</h3> Ninety-three consecutive patients with ALL treated on protocols containing HDMTX. <h3>Intervention</h3> Two doses of HDMTX were used, based on clinician preference. Each clinician used a uniform strategy for all her/his patients; toxicity risk was not used to determine the dose. <h3>Main outcome measures</h3> We compared methotrexate toxicities, including acute kidney injury, mucositis, infections, hemorrhage, hospital length-of-stay and delay of subsequent treatment cycles. Patient outcomes were also assessed, but with the short follow-up time, no difference in survival would be expected unless toxicities were extreme. <h3>Results</h3> Toxicities were uncommon in all patients (age 3 months to 19 years) who received 330 courses of HDMTX (103 courses of 2 g/m² and 227 courses of 5 g/m²). There was one death in the 5 g/m² arm due to severe mucositis. Mucositis in 5 g/m² was 6/227 (2.6%) and in 2 g/m² was 1/103 (0.97%) (p=0.34). Two courses were complicated by acute kidney injury (1 in each group, p=1.0), and infections occurred in 32/227 (14.1%) higherdose courses versus 8/103 (7.7%) lower-dose courses (p=0.1). Length of stay was 4.8 days in both groups (p=0.88). <h3>Conclusions</h3> HDMTX up to 5 g/m² can be safely delivered, even in a limited-resource setting and no access to methotrexate levels. One death with severe mucositis suggests that monitoring methotrexate levels could improve safety even more.

Assessing the impact of adding acetazolamide to oral or intravenous sodium bicarbonate as compared with intravenous bicarbonate monotherapy as urinary alkalinization in adults receiving high-dose methotrexate

High-dose methotrexate (HD-MTX) requires urine alkalinization to pH ≥ 7 for adequate excretion to prevent toxicity. Due to shortages of IV sodium bicarbonate (IV-NaHCO3), few reports have demonstrated utility of oral bicarbonate (PO-NaHCO3); however, the addition of acetazolamide (Acet) has not been well described. Our study compares outcomes between alkalinization methods of IV-NaHCO3 monotherapy versus IV-NaHCO2 + Acet and PO-NaHCO3 + Acet. A single-center, IRB exempt, retrospective review was conducted from Jan 2016 to Sept 2019 of adults receiving HD-MTX ≥ 500mg/m2. The primary outcome was time from start of alkalinization to pH ≥ 7. Secondary outcomes included time from start of alkalinization to initiation of HD-MTX, time to MTX clearance, length of stay (LOS), percentage of urine pH assessments < 7, and incidence of MTX toxicity. Statistical analysis was performed using SAS9.4 with alpha 0.05. Overall demographics (n = 196 HD-MTX cycles for 55 patients) include a mean age 55years, HD-MTX dose ~ 5400mg/m2, and 69% with a diagnosis of lymphoma. Adjusting for baseline demographic differences among groups, median time from first dose alkalinization to pH ≥ 7 and to start of HD-MTX was longer for those receiving IV-NaHCO3 (n = 41) vs either IV-NaHCO3 + Acet (n = 70) or PO-NaHCO3 + Acet (n = 76) (p = 0.0001). HD-MTX clearance to a level < 0.1μmol/L was not improved with the addition of Acet. No difference existed among groups for pH results < 7, LOS, or incidence of MTX toxicity (p > 0.05). Addition of Acet to NaHCO3 reduces time to pH ≥ 7 and initiation of HD-MTX but does not appear to improve LOS, MTX toxicities, or time to MTX clearance.

Effect of access to care on outcomes of rural and elderly patients with primary central nervous system lymphoma.

e14008 Background: Primary central nervous system lymphoma (PCNSL) can often be cured, especially in younger patients, but requires intense chemotherapy with high-dose methotrexate (HDMTX) and rituximab to optimize outcomes. Toxicities can lead to dose reduction or omission that may increase relapse risk, or lead clinicians to select less effective regimens that do not contain HDMTX. Methods: Anonymized, de-identified data of patients from 110 community oncology practices of the Guardian Research Network (GRN, www.GuardianResearch.org ) was analyzed to determine treatments, toxicities, and outcomes of adults with PCNSL. All data from the medical record is available from GRN (diagnoses, demographics, labs, medicines, toxicities, radiology, pathology, procedures, and encounters), so each patient’s journey can be fully characterized. Results: Of 533805 adults with cancer, 49 were treated for PCNSL with HDMTX-containing regimens (n = 35), other chemotherapy regimens (n = 3), or radiation therapy (RT) alone (n = 11). HDMTX patients received HDMTX only in 8 cases, HDMTX plus rituximab in 23 cases, addition of RT in 11 cases, and HDMTX with other chemotherapy but no rituximab in 3 cases. Survival at 5 years was 53% (standard error [SE] 8.6%) for patients treated with HDMTX versus 33% (SE 13%) for those treated with other therapies. Of those treated with HDMTX, survival was 0% for patients who experienced early toxicity that required cessation of HDMTX prior to receiving 3 doses and having response evaluated versus 62% (SE 9.1%) for patients who received 3 or more courses of HDMTX (p &lt; 0.001). In a multivariable Cox proportional hazards model including completion of at least 3 doses of HDMTX, age, race, and sex, only lack of HDMTX toxicity was associated with survival (hazard ratio 0.22, 95% confidence interval 0.07 to 0.70, p = 0.01). Conclusions: Use of HDMTX and prevention of toxicity improves outcomes for PCNSL patients treated in the community.

Patient selection and tolerability of high-dose methotrexate as central nervous system prophylaxis in diffuse large B-cell lymphoma.

Central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) is usually fatal. Risk stratification of patients has historically been poorly defined, and CNS prophylaxis with high-dose methotrexate (HDMTX) can be associated with multiple toxicities. The CNS International Prognostic Index (IPI) defines three patient risk groups for CNS disease. The aims of this study were to evaluate the toxicity of HDMTX and describe outcomes in HDMTX and non-HDMTX patients according to the CNS-IPI. 205 patients diagnosed with DLBCL between 2004 and 2014, initially treated with RCHOP-like chemotherapy and considered for HDMTX CNS prophylaxis were identified by pharmacy records at two teaching hospitals. Patient records were retrospectively reviewed for HDMTX toxicity, CNS-IPI calculation and CNS relapse. 28 patients with DLBCL were selected for two doses of HDMTX. Two of 28 patients received only one dose, and three had their second dose reduced due to renal impairment. 28% of patients experienced nephrotoxicity. 24 HDMTX and 122 non-HDMTX patients were evaluable for the CNS-IPI. No significant difference in the CNS-IPI distribution between the two groups was identified (p = 0.695). Five patients had CNS relapse, two who received HDMTX and three who did not. No significant difference in CNS relapse rate was identified between 24 HDMTX patients propensity-matched to 24 non-HDMTX patients. HDMTX was well-tolerated by patients. Application of the CNS-IPI identifies a different population of candidates for CNS prophylaxis compared to traditional criteria.

Effect of Levetiracetam on Time to High-Dose Methotrexate Clearance in Patients With Hematologic Malignancies.

High-dose methotrexate (HDMTX) is a commonly used treatment for hematologic malignancies involving the central nervous system. Two case reports described possible delayed methotrexate clearance in patients receiving concurrent levetiracetam, while a retrospective cohort study did not find this association. The objective of this single-center, retrospective case-control study of 121 patients who received their first cycle of HDMTX was to investigate the association between HDMTX clearance time and concomitant levetiracetam use. The most common diagnosis was primary central nervous system lymphoma (47.9%). The mean HDMTX dose was 4601 mg/m2 (standard deviation [SD], 2052.6mg/m2 ). Concurrent levetiracetam was administered in 30 of 121 patients (24.8%), with a mean total daily levetiracetam dose of 1434.4mg (SD, 622.9mg; range, 900-3000mg). Baseline characteristics were similar between patients who received concomitant levetiracetam and those who did not. The mean time to methotrexate clearance was 82.5 hours (SD, 51.2; 95% confidence interval, 69.4-95.7) in the concomitant levetiracetam group and 72.4 hours (SD, 31.2; 95% confidence interval, 61.7-83.0) in the nonlevetiracetam group, which was not significantly different (P > .05), even in the subgroup receiving methotrexate doses >3500mg/m2 . Grade 3 or higher toxicity occurred in 33.3% of the concomitant levetiracetam group and in 34.1% of nonconcomitant levetiracetam patients. This study, which, to our knowledge, is the first examining levetiracetam effect on only the first dose of HDMTX, supports the larger retrospective study finding no significant effect of levetiracetam on HDMTX clearance time, and suggests that administering concomitant levetiracetam does not affect HDMTX toxicity.

Long-term outcomes of modified BFM-95 regimen in adults with newly diagnosed standard-risk acute lymphoblastic leukemia: a retrospective single-center study.

The standard treatment for adult acute lymphoblastic leukemia (ALL) is undefined. Patients with newly diagnosed standard-risk ALL at a single institution were retrospectively analyzed. From 2010 to 2017, 46 patients were treated using the modified Berlin-Frankfurt-Münster (BFM)-ALL-95 regimen. Hematologic and molecular complete remission (CR) rates of 91.3% and 76.1% were achieved. The 5-year event-free survival (EFS) and overall survival (OS) rates for all patients in the cohort were 58.0% (95% confidence interval, 42.1-73.9%) and 66.7% (95% CI, 51.4-82.0%), respectively. No patient presented with central nervous system involvement after CR in this study. This condition could be related to four doses of high-dose methotrexate (MTX) every 3months during the maintenance phase. Multivariate analysis revealed that minimal residual disease positive and time interval between induction IA and Protocol M of more than 70days were independent adverse factors for EFS and OS. One or more instances of grade 4 myelosuppression occurred during induction therapy. Nonhematological side effects were mild. No toxicity-related deaths were observed in the entire cohort. The data indicated that the modified regimen is well tolerated and can produce the promising outcomes in Chinese adults with standard-risk ALL.

Isolated late testicular relapse of B‐cell acute lymphoblastic leukemia treated with intensive systemic chemotherapy and response‐based testicular radiation: A Children's Oncology Group study

The incidence of isolated testicular relapse (ITR) of acute lymphoblastic leukemia (ALL) has decreased with contemporary treatment strategies, but outcomes are suboptimal with a 58% 5-year overall survival (OS). This study aimed to improve outcome in patients with ITR of B-cell ALL (B-ALL) occurring after 18 months of first clinical remission using intensive systemic chemotherapy and to decrease long-term sequelae by limiting use of testicular radiation. Forty patients in first ITR of B-ALL were enrolled. Induction (dexamethasone, vincristine, daunorubicin, and intrathecal triple therapy) was preceded by one dose of high-dose methotrexate (MTX, 5g/m2 ). Following induction, 25 of 26 patients who had persistent testicular enlargement underwent testicular biopsy. Eleven had biopsy-proven disease and received bilateral testicular radiation (24Gy), whereas twenty-nine did not. Overall 5-year event-free survival (EFS)/OS was 65.0 ± 8.8%/73.1 ± 8.3%, with 5-year EFS 62.1 ± 11.0%vs. 72.7 ± 14.4% for patients who did not receive radiation therapy (XRT) (n=29) compared with those who did (n=11), respectively (P=0.64). There were six second bone marrow relapses and six second ITRs. The proportion of second relapses was similar in the patients that received testicular radiation and those who did not. However, the 5-year OS was similar for patients who did not receive XRT (72.6 ± 10.2%) compared with those who did (72.7 ± 14.4%) (P=0.85). A 5-year OS rate of 73.1±8.3% was obtained in children with first ITR of B-ALL occurring after 18 months of CR1 (length of first clinical remission) using intensive chemotherapy and limiting testicular radiation.

Phase 1B of ibrutinib and high-dose methotrexate for recurrent/refractory CNS lymphoma.

7533 Background: Primary CNS Lymphoma (PCNSL) is an aggressive primary brain tumor. Outcome and treatment options for patients with recurrent/refractory (r/r) disease are poor. We have observed promising efficacy of single agent ibrutinib in r/r PCNSL and secondary CNS lymphoma (SCNSL). In this phase 1B trial, we investigate the toxicity of ibrutinib in combination with high-dose methotrexate (HD-MTX) in r/r PCNSL/SCNSL. Methods: Eligible patients had r/r PCNSL/SCNSL or newly diagnosed SCNSL, age≥18, ECOG≤2, normal end-organ function, and with any number and type of prior therapies. In patients with SCNSL disease, systemic disease needed to be absent. HD-MTX was given at 3.5g/m2 every 2 weeks for a total of 8 doses. To minimize adverse events, ibrutinib was stopped on days of HD-MTX infusion and was restarted 5 days after MTX infusion or after completion of MTX-clearance, if clearance of MTX required more than 5 days. Ibrutinib was continued daily after completion of 8 doses of MTX. Results: Six patients have been enrolled; 3 received 560mg and 3 received 840mg ibrutinib in combination with HD-MTX. Median age was 62 (range 43-74); median ECOG 1 (0:2; 1:3; 2:1). Two had r/r PCNSL and 4 SCNSL. Three had brain disease, one isolated cerebrospinal fluid (CSF) involvement and two parenchymal and CSF involvement. Three patients had recurrent (2 PCNSL; 1 SCNSL), two refractory (both SCNSL), and one newly diagnosed disease (SCNSL). There were no grade 4 adverse events. Grade 3 events were observed in 5 patients (lymphopenia in 3, ALT elevation in 2, diarrhea in 1, electrolyte changes in 1, hypertension in 1). The most common adverse events were hypokalemia, low WBC, hyperglycemia, ALT and AST elevation. There was no dose reduction of methotrexate or ibrutinib in any patient. After a median follow-up of 130 days, all patients were evaluated for response after 4 doses of HD-MTX, with 4/6 (67%) showing a response: 2 CR, 2 PR, and 1 SD, 1 PD; both non-responders were refractory SCNSL. Ibrutinib concentrations were measured in plasma and CSF. Conclusions: Patients with CNS lymphoma tolerate the combination of HD-MTX and Ibrutinib (at 560 and 840mg) well. Continued enrollment into a combination arm that includes rituximab, methotrexate and ibrutinib is ongoing. Clinical trial information: NCT02315326.

Patient Selection for High-Dose Methotrexate As Central Nervous System Prophylaxis in Diffuse Large B-Cell Lymphoma in Australia: Are We Getting It Right?

Introduction: Diffuse large B cell lymphoma (DLBCL) is the most common lymphoid malignancy. While central nervous system (CNS) relapse in DLBCL is uncommon, it is usually fatal. As many relapses are parenchymal, systemic high-dose methotrexate (HDMTX) has largely replaced intrathecal methotrexate as CNS prophylaxis in high risk patients (historically characterised using IPI score/number of extranodal sites) in Australia. However, the efficacy of HDMTX in this context remains undetermined, can be associated with nephrotoxicity, myelosuppression and hepatotoxicity and necessitates the use of significant hospital resources for administration and monitoring. The German high-grade non-Hodgkin lymphoma study group (DSHNHL) prognostic model separates patients with DLBCL into 3 risk groups for CNS disease based on a score derived from 6 factors. The aims of this study were to evaluate the toxicity of HDMTX, and describe outcomes in HDMTX and non-HDMTX patients according to the DSHNHL model.Methods: 150 patients diagnosed with DLBCL between 2004 and 2014, initially treated with RCHOP-like chemotherapy and given or not given HDMTX for CNS prophylaxis were identified by pharmacy records at two teaching hospitals. Patient records were retrospectively reviewed for HDMTX toxicity, CNS disease risk factors as specified in the DSHNHL model and CNS relapse. All surviving patients had at least a year of follow-up. The toxicity parameters of 28 HDMTX patients was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4, up to 30 days from the date of the last dose of HDMTX. Statistical analysis was performed using STATA Data Analysis and Statistical Software version 13. Analysis involved Fisher's exact test for categorical variables and Mann-Whitney U test for continuous variables. A p-value was statistically significant if it was equal to or less than 0.05.Results: 28 patients with DLBCL selected to receive HDMTX were planned for 2 doses. All initial doses were administered at a concentration of 3g/m2 except for 2 patients who had a first dose of 1.5g/m2. Two of 28 patients received only one dose, and 3 had their second dose reduced, all due to renal impairment. 20 of 28 patients (71%) did not experience nephrotoxicity and no patient progressed to grade 4 or 5 renal toxicity. Myelosuppression was the most common toxicity, with anaemia grade 3-4 in 1 (4%), grade 3 and 4 neutropenia in 8 and 3 (but with febrile neutropenia in only one case) and grade 3-4 thrombocytopenia in 2 (7%) patients.24 of 28 HDMTX patients and 122 non-HDMTX had sufficient data available for the 6 components of the DSHNHL model. Comparison of the DSHNHL model score for HDMTX and non-HDMTX patients showed no significant difference in the distribution of scores (p-value 0.478). No patient had all 6 factors. Fourteen (58%) HDMTX and 66 (54%) non-HDMTX patients were categorized as low risk (score 0 to 2), 8 (33%) HDMTX and 31 (25%) non-HDMTX were intermediate risk (score 3) and 2 (8%) HDMTX and 25 (20%) non-HDMTX were high risk (score 4 to 6) according to the DSHNHL model.The 2 (of 24) HDMTX patients who relapsed in the CNS had DSHNHL model scores of 1 and 3. Of the 122 non-HDMTX patients, 3 relapsed in the CNS, all with intermediate or high risk disease.Conclusions: HDMTX was well-tolerated by patients, therefore can safely be administered as CNS prophylaxis under current hospital protocols. Application of the DSHNHL prognostic model identifies a different population of candidates for CNS prophylaxis compared to historical risk factors and may lead to better patient selection for this intervention. DisclosuresHawkes:Merck Serono: Research Funding; BMS: Other: travel expenses, Research Funding; Takeda: Other: travel expenses.