High-dose Methotrexate and Rituximab Induction Regimen In Immunocompetent Patients With Primary CNS Lymphoma: A Retrospective Single-Center Study of Survival Predictors

Purpose: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 have been largely controversial. Herein, we sought to explore the impact of adjuvant Rituximab and different dosages of HD-MTX on survival outcomes of immunocompetent patients with PCNSL.Methods: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.Results:There is no significant difference in survival among patients who received MTX alone versus MTX plus Rituximab. Furthermore, lower doses of MTX were associated with worse survival outcomes; however, this difference in survival was not significant when adjusted to age.Conclusion: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.

Timing of high dose methotrexate CNS prophylaxis in DLBCL: a multicenter international analysis of 1,384 patients

Prophylactic high-dose methotrexate (HD-MTX) is often used for diffuse large B-cell lymphoma (DLBCL) patients at high risk of central nervous system (CNS) relapse, despite limited evidence demonstrating efficacy or the optimal delivery method. We conducted a retrospective, international analysis of 1,384 patients receiving HD-MTX CNS prophylaxis either intercalated (i-HD-MTX) (n=749) or at the end (n=635) of R-CHOP/R-CHOP-like therapy (EOT). There were 78 CNS relapses (3-year rate 5.7%), with no difference between i-HD-MTX and EOT; 5.7% vs 5.8%, p=0.98, 3-year difference: 0.04% (-2.0% to 3.1%). Conclusions were unchanged on adjusting for baseline prognostic factors or on 6-month landmark analysis (n=1,253). In patients with high CNS international prognostic index (n=600), 3-year CNS relapse rate was 9.1% with no difference between i-HD-MTX and EOT. On multivariable analysis, increasing age and renal/adrenal involvement were the only independent risk factors for CNS relapse. Concurrent intrathecal prophylaxis was not associated with reduction in CNS relapse. R-CHOP delays of ≥7 days were significantly increased with i-HD-MTX versus EOT, with 308/1573 (19.6%) i-HD-MTX treatments resulting in delay to subsequent R-CHOP (median 8 days). Increased risk of delay occurred in older patients when delivery was later than day 10 in the R-CHOP cycle. In summary, we found no evidence that EOT delivery increases CNS relapse risk versus i-HD-MTX. Findings in high-risk subgroups were unchanged. Rates of CNS relapse in this HD-MTX-treated cohort were similar to comparable cohorts receiving infrequent CNS prophylaxis. If HD-MTX is still considered for certain high-risk patients, delivery could be deferred until R-CHOP completion.

Rituximab With High-Dose Methotrexate In Newly Diagnosed Primary Central Nervous System Lymphoma: a Single-Center Experience From China

Induction chemotherapy based on high-dose methotrexate is considered as the standard approach for newly diagnosed primary central nervous system lymphomas (PCNSLs). However, the best combination chemotherapeutic regimen remains unclear. This study aimed to determine the efficacy and toxicities of rituximab with methotrexate (R-M regimen). Consecutive 37 Chinese patients receiving R-M regimen as induction chemotherapy were retrospectively identified from January 2015 to June 2020 from our center in eastern China. Fourteen patients receiving rituximab plus methotrexate with cytarabine (R-MA regimen) at the same period were identified as the positive control group. The response rates, survival, toxicities, length of hospital stay (LOS), and cost were compared. Compared with the R-MA regimen, the R-M regimen showed comparable response rate and survival outcomes, but had fewer grade 3-4 hematological toxicities, shorter LOS, lower mean total hospitalization cost and lower mean total antibiotic cost. Overall response after two cycles of chemotherapy, complete remission at the end of induction chemotherapy and ECOG>3 were independent prognostic factors for overall survival. In conclusion, R-M regimen is an effective and well-tolerated combination treatment for PCNSLs, which warrants further evaluation in randomized trials.

Retrospective evaluation of sodium acetate use for urine alkalinization in patients receiving high dose methotrexate

Purpose Methotrexate is an antifolate agent used in treatment of several malignancies. Many toxicities accompany methotrexate that are minimized with urine alkalinization. Parenteral sodium bicarbonate is the historical standard alkalinizing agent, but use has been limited by intermittent shortages. However, intravenous sodium acetate may be considered as a chemically equivalent alternative. The primary objective of this study is to determine the efficacy of sodium acetate versus sodium bicarbonate for urine alkalinization for high-dose methotrexate (HDMTX). Methods This is a retrospective cohort study including adults admitted to Barnes-Jewish Hospital to receive HDMTX for lymphoma, breast cancer with leptomeningial spread, or osteosarcoma. Patients must have received intravenous sodium acetate or sodium bicarbonate alkalinization. Results Of 192 HDMTX encounters, 154 (sodium bicarbonate, n = 86; sodium acetate, n = 68) were evaluated for efficacy and safety. Safety outcomes were not significantly different between groups except for higher peak methotrexate level in the bicarbonate group (2.9 mcmol/L vs. 1.7 mcmol/L, p = 0.023), and increased incidence of grade 3–4 ALT in the sodium bicarbonate group (23.5% vs. 9%, p = 0.02). Time from alkalinizer initiation to pH ≥7 was significantly shorter with sodium bicarbonate (4 vs. 5.15 h, p = 0.021). Nonetheless, outcomes such as length of stay (4.4 vs. 4 days respectively, p = 0.037) and time to methotrexate clearance (3.6 vs. 3.2 days respectively, p = 0.023) reveal that inpatient time was shorter with sodium acetate overall. Conclusion This retrospective analysis suggests that sodium acetate has similar efficacy and safety to sodium bicarbonate for alkalinization and may be considered as an alternative in future shortage situations.

Use of the extracorporeal detoxification methods for methotrexate elimination

The article considers a clinical case of a 12-year-old child with osteosarcoma of the left tibia, T1N0M0G3, treated with high-dose methotrexate 12 g/m2. As a result of delayed elimination of methotrexate, the patient developed acute liver failure. The ALT level increased to 4790 U/L, AST — to 4320 U/L, which indicates life-threatening acute liver damage. There was no coagulopathy, significant increase in bilirubin, and hepatic encephalopathy. The timely use of efferent therapy allowed avoiding the complete course of acute liver failure. The patient received intravenous hydration therapy and urine alkalinization with 3000 ml/m2/day of 5% glucose in combination with 20 μmol NaHCO3/L and 20 μmol KCl/L. The urine output was more than 600 ml/m2/6 hours. Additionally, antidote therapy with calcium folinate was administered. In this case, we used continuous venous-venous hemodiafiltration using Prismaflex. After the first session, which lasted for 78 hours, there was a re-increase in serum methotrexate concentration and ALT, AST levels, which indicates a large volume of distribution of methotrexate and the need for long-term extracorporeal therapy. Therefore, the second session of continuous venous-venous hemodiafiltration was provided. After the second session, there was no re-increase in methotrexate level in the blood and the transaminases and total bilirubin returned to normal levels. Additionally, the patient was tested for homocysteine levels for hyperhomocysteinemia, as well as 4 genes that also determine the predisposition to hyperhomocysteinemia — methylenetetrahydrofolate reductase gene MTHFR C677T, A1298C, methionine synthase MTRR, and MTR. The presence of elevated levels of homocysteine, as well as heterozygosity of these genes, indicate a slow excretion of methotrexate or a complete delay in its excretion. Our patient presented the negative results of these tests. Conclusions. This clinical case indicates the effectiveness of continuous venous-venous hemodiafiltration in combination with intravenous hydration, urine alkalinization, and antidote therapy in the treatment of hepatotoxicity of high-dose methotrexate on the background of delayed excretion.