NCMP-14. WHOLE BRAIN RADIOTHERAPY COMBINED WITH INTRATHECAL LIPOSOMAL CYTARABINE FOR LEPTOMENINGEAL METASTASIS – A SAFETY ANALYSIS AND VALIDATION OF THE EANO-ESMO CLASSIFICATION

BACKGROUND Although there is no proven standard therapy for leptomeningeal metastases (LM), treatment often includes intrathecal chemotherapy combined with whole brain radiation therapy (WBRT). Little is known on the toxicity of such combination therapies. We performed a retrospective safety analysis for the combination of intrathecal liposomal cytarabine with WBRT in patients with LM and validated the EANO-ESMO classification in this unique cohort. METHODS Treatment toxicities in patients diagnosed with LM between 2004 and 2014 were retrospectively analyzed according to the RTOG (Radiation Therapy Oncology Group) and NCI CTCAE V5.0 (Common Toxicity Criteria Adverse Events) toxicity criteria. Diagnostic criteria and treatment response as assessed by EANO-ESMO classification were correlated with survival by Kaplan Meier analysis and Breslow test. RESULTS 40 patients with LM who were treated with combined WBRT and intrathecal cytarabine, were identified. Ten patients (25%) experienced adverse events ≥ grade 3 according to the RTOG-toxicity criteria, in 22 patients (55%) CTCAE criteria ≥3 grade were detected. Median overall survival (mOS) was 124.0 days [72.9;175.1]. Median time to neurological progression was 52.0 days [41.1; 62.8]. When comparing the diagnostic criteria, patients with a positive CSF cytology (n=26) showed worse prognosis compared to patients with a negative CSF cytology (n=14) (mOS 84 days [44.0;124.0] versus 198.0 days [162.6;233.4] days, p=0.006, respectively). The EANO-ESMO response assessment correlated significantly with survival - “stable” (n=7) mOS 233.0 [76.5;389.5] days, “response” (n=10) mOS 206.0 [193.9;218.9] days, “progression” (n=17) mOS 45.0 [34.4;55.6] days, “suspicion of progression” (n=6) mOS 133.0 [65.8;200.2] days (overall, p< 0.001). CONCLUSIONS In this retrospective analysis, the treatment combination of WBRT and intrathecal liposomal cytarabine shows an acceptable safety profile. The EANO-ESMO classification for diagnosis and treatment response predicts survival

DDEL-03. LONG-TERM INTRAVENTRICULAR THERAPY ALTERNATING ETOPOSIDE AND LIPOSOMAL CYTARABINE: EXPERIENCE IN 75 CHILDREN AND ADOLESCENTS WITH MALIGNANT BRAIN TUMORS

BACKGROUND Malignant brain tumors of childhood carry a high risk for leptomeningeal dissemination and tumor cells floating in the CSF are often not amenable to systemic and/or antiangiogenic chemotherapy. We report on our experience with an intraventricular therapy consisting of alternating cycles of liposomal cytarabine and etoposide. PATIENTS AND METHODS Between 2004 and 2017, 75 patients aged 0.6 to 22 years (median 11) with various malignant brain tumors received intraventricular etoposide 0.25mg (<1year) - 0.5mg on five consecutive days alternating with liposomal cytarabine at a dose of 25mg (<3 years) - 50mg via an Ommaya reservoir. RESULTS 5533 doses of etoposide (5–277/patient, median 141) corresponding to 1–56 five-day-cycles/patient alternating with 534 doses of liposomal cytarabine (1–21/patient, median 11) were administered. Treatment was given over a period of 1 – 146 months (median 73.5). Toxicities did occur but were infrequent and mostly mild. Since all patients received some sort of concurrent anti-cancer therapy, the efficacy of intrathecal therapy cannot be assessed independently. However, 29/75 patients are still alive, and none of the patients had tumor cells in the CSF at their last evaluation. CONCLUSION In conclusion, alternating intraventricular liposomal cytarabine and etoposide produced responses and proved to be an important adjunct for patients receiving drugs with a low penetrance into the CSF. Since production of liposomal cytarabine was discontinued in 2017 it remains to be determined whether substitution of the slow release formulation by aqueous cytarabine on days 1, 4, 8, and 11 may produce similar results.

Final Report of Reduced Anthracycline Dose Intensity with the Addition of Dose Dense Rituximab in Children, Adolescents and Young Adults with De Novo Good Risk Mature B-Cell Non Hodgkin Lymphoma (B-NHL)

Background: Previous studies have demonstrated excellent results with FAB/LMB86 chemotherapy alone and in combination with rituximab in children, adolescents and young adults with mature B-NHL. (Cairo et al, JCO 2012, Goldman et al, Leukemia, 2013, Goldman et al, BJH 2014) The intermediate risk FAB/LMB Group B arm consists of 180mg/m2 of doxorubicin. This was reduced to 120mg/m2 with the addition of dose-dense rituximab. Other standard NHL regimens more commonly used in young adults with advanced stage mature B-NHL, such as R-CHOP, have a total dose doxorubicin of 360mg/m2. These approaches are associated with short term morbidities and long-term health conditions, including anthracycline induced cardiac toxicities.Dose-dense rituximab containing chemoimmunotherapy in high risk mature B-NHL has shown significant improvements in outcomes. We tested the hypothesis that rituximab can be used to even further reduce the burden of anthracycline from 120mg/m2 to 50mg/m2 in patients with good risk B-NHL. Objective: To safely reduce the burden of therapy by reducing the number of IT injections and reducing the total dose of doxorubicin from 120mg/m2 to 50mg/m2 with the addition of liposomal cytarabine and dose-dense rituximab to our prior chemotherapy backbone in children with good risk mature B-NHL. Design/Methods: Multi-institutional Phase II study (NCT01859819). Patients (3-31 years) with CD20+ B-NHL with good risk (FAB Group B GR=Stage I/II, Stage III with any LDH and Stage IV {BM tumor < 25%)}) were eligible. Staging was defined per the IPNHLSS as previously described. (Roselen et al, JCO 2015) All patients received FAB backbone chemotherapy with the addition of six rituximab (375mg/m2) doses; two doses prior to each of two induction courses and one dose prior to each of two consolidation courses. Cumulative doxorubicin was reduced from 120 to 50 mg/m2 (25mg/m2 per dose) total. After systemic methotrexate clearance, patients received age-based dosing of IT liposomal cytarabine resulting in a reduction of IT injections from nine to five. The primary outcome was safety and toxic deaths with an estimated 3-year survival above 90%, monitored by an independent DSMB. Response was defined per the IPNHLRC as previously described. (Sandlund et al, JCO 2015) Results: Twenty-five FAB Group B patients were enrolled at 5 treatment centers in the United States. Histology included DLBCL in 13 patients and Burkitt in 12 patients. Table 1. All patients had at least a 20% tumor decrease after the reduction phase. Two patients were upstaged to intensified Group C therapy after residual imaging findings post first consolidation. Therefore, 23/25 patients had a cumulative doxorubicin exposure of 50 mg/m2 while the two patients who received augmented treatment had a total exposure of 170 mg/m2. There were no serious adverse events reported with rituximab administration and no reported CNS or other toxicity reported with liposomal cytarabine intrathecal prophylaxis. During the two induction cycles there were no readmissions for febrile neutropenia or other causes and no reported grade III or higher mucositis. Follow up immune globulin levels on a smaller cohort of patients revealed median IgG levels of 821 (range, 362-1172) at a median follow up of 24 months. All patients are alive and in first remission with an EFS/OS = 100% at a median follow up of 4 years (range, 2-7yr). Figure 1. Echocardiograms revealed stable left ventricular function. Rituximab CSF levels were measured as we previously described and were extremely low (< 10µg/ml) compared to peak serum levels (250-400µg/ml). Conclusions: Our results demonstrate the feasibility of careful reduction of anthracycline dose intensity with the addition of dose-dense rituximab immunotherapy in children, adolescents and young adults with good risk mature B-NHL. Our results demonstrate a 100% EFS/OS with a reduction to only 50mg/m2 total dose of anthracycline. This is consistent with published standard of care outcomes utilizing much higher doses of 120-550mg/m2 of doxorubicin. Our treatment strategy benefits good risk patients with mature B-NHL by using dose-dense rituximab to reduce the cumulative exposure of anthracycline associated short- and long-term toxicities as well as the number of required intrathecal injections. These excellent results require the investigation of this approach in a larger cohort in the future to confirm these preliminary findings. Disclosures Goldman: Jazz Pharmaceuticals, Inc.: Speakers Bureau. Harker-Murray:Regerenon Pharmaceuticals: Consultancy. Cairo:Miltenyi: Research Funding; Technology Inc/Miltenyi Biotec: Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Nektar Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Liposomal Cytarabine as Cancer Therapy: From Chemistry to Medicine

Cancer is the second leading cause of death worldwide. The main modality to fight against cancer is surgery, radiotherapy, and chemotherapy, and more recently targeted therapy, gene therapy and immunotherapy, which play important roles in treating cancer patients. In the last decades, chemotherapy has been well developed. Nonetheless, administration of the drug is not always successful, as limited drug dosage can reach the tumor cells.. In this context, the possibility to use an encapsulated anti-cancer drug may potentially solve the problem. Liposomal cytarabine is a formulation with pronounced effectiveness in lymphomatous meningitis and reduced cardiotoxicity if compared to liposomal anthracyclines. Thus, the future liposomal cytarabine use could be extended to other diseases given its reduction in cytotoxic side effects compared to the free formulation. This review summarizes the chemistry and biology of liposomal cytarabine, with exploration of its clinical implications.