Exceptional Efficiency and Tolerance of Temozolomide in Relapse/Refractory Primary Intra-Ocular Lymphoma (R/R PIOL)
Authors: Choquet Sylvain , Cassoux Nathalie , Merle-Beral Hlne , Leblond Veronique 
Published: October 2019

Abstract
Abstract 4939

Background:
PIOL is a very rare subset of non Hodgkin lymphoma, usually arising in elderly patients and characterized by a high level of relapse, mainly in the first year, with more than 10 of cases relapsing in brain, and a short survival. There is no consensus on treatment procedures, even in first line, and prospective comparative studies do not exist. Classical attitudes are systemic chemotherapy (SC), often high dose methotrexate, radiotherapy or intraocular injection of methotrexate (IM) but publication on R/R PIOL are exceptional. New treatments are necessary, especially with a good tolerance profile. As Temozolomide (Te) hassome efficiency on primary-central-nervous-system lymphoma (PCNSL) we used this drug in R/R PIOL in our center.

Methods:
Inclusion criteria were a diagnosis established on cytological and molecular analysis after vitrectomy or anterior chamber puncture, and the absence of brain or meningeal localization. Treatment consisted in Te at 150mg/m2orally 5 days per month, without corticosteroid use, in absence of any response, dosage was increased to 200mg/m2. A complete response was defined as a normalization of eye exam and intraocular interleukins 10 and 6.

Results:
Six patients were analyzed, 2 males and 4females, mean age 70 years \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{49}{82}.\) \end{document}. All received systemic chemotherapy with at least high dose methotrexate and high dose cytarabin before Te, five were in second line and one in third, after autologous hemopoietic stem cells transplantation (ASCT) conditioned by thiotepa, cyclophosphamide and busulfan. Mean response duration before Te was 241 days \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{23}{524}.\) \end{document}. All but one received Te in monotherapy, one having an association with ifosfamid followed by ASCT. CR has been obtained in 3 patients, PR in one, progressive disease in two. One of the 3 patients in CR stopped Te by himself after three months, relapsed two months later and is again in CR after reintroduction of Te. CR patients are still disease free at 42, 190 and 878 days; two of these patents described a clear improvement of their vision as soon as one or two weeks after Te introduction. Overall survival for the six patients, from day 1 of Te is 313 days \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\frac{101}{1001}.\) \end{document} No grade 3/4 toxicity has been described.

Conclusion:
This study describe for the first time use of Te in PIOL, and in this very rare disease, it represents significant series. Te appears as a safe and efficient treatment of R/R PIOL, even after high dose chemotherapy and/or in elderly patients. Longer follow-up and larger studies are necessary to confirm these data.

Disclosures:
No relevant conflicts of interest to declare.