L-Asparaginase and Steroids
CSVT developed in patients receiving a combined therapy of ASP and steroids. The most commonly used ASP product was that of the nativeE. coli (KidrolaseR; EUSA Pharma, France). CSVT rates were observed to differ with different treatment regimens depending on the type of ASP or steroid used. CSVT occurred in patients who received either native L asparginase or Pegylated ASP as the predominant ASP product, whereas none of the patients who received Erwinia-derived ASP as the predominant ASP product developed CSVT. Furthermore, 77% of CSVT events occurred while receiving combined ASP and dexamethasone treatment (during Reinduction I or II or the first 20 weeks of continuation therapy in Int/high risk patients) compared to 23% of events that occurred during combined ASP and prednisone therapy (Induction). Of note is that all patients treated as per our protocol received only 2 or 3 weeks of combined asparginase and Prednisone (40 mg/m2/day), whereas they received 4 weeks of dexamethasone if they were classified as low risk or 19 weeks of combined dexamethasone and asparginase if classified as Int/ high risk thus resulting in more exposure to the dexamethasone/aspa combination.