A dose and schedule optimizing evaluation of MG98 given as either a 2 hour IV infusion twice weekly or as a 7 day continuous infusion in combination with interferon alpha (INF) in nephrectomized patients (pts) with advanced renal cell carcinoma (RCC)

14557 Background: RCC is often associated with hypermethylated and silenced tumour suppressor genes. The enzyme DNMT1 is responsible for the majority of cellular DNA methylating capacity. MG98 is a second generation antisense inhibitor of DNMT1 which has been shown to reduce DNMT1 mRNA and protein. Methods: A trial of MG98 given as a 2 hour IV infusion twice weekly (Intermittent Schedule, IS) or as a 7 day continuous infusion (CI) in combination with INF has been conducted with nephrectomized pts with advanced RCC. Main endpoints: identification of the optimum regimen, safety, tolerability, pharmacokinetics (PK) and the degree of PBL DNMT1 mRNA suppression. Results: CI schedule: dose levels of 125mg of MG98 combined with 12 MIU of INF (125/12) and 125/9 have been evaluated (9 pts). The MTD has been reached; thrombocytopenia is dose limiting at 125/12. Pt demographics: M:F= 6:3, mean age of 63.2y (52–71). Most common Adverse Events (AEs): fever and chills (gr.1), fatigue (gr.1–2; 100% of pts), nausea and anorexia (gr.1–2), vomiting (gr.2; 66%). Best response: Stable Disease (SD) =3; Partial Response (PR) =1. Currently within the IS schedule, 3 dose levels (9 pts) have been evaluated: 160/12, 200/12 and 200/9, totaling 26 cycles. The MTD has been reached, with GI/constitutional symptoms being dose limiting at 200/12. Demographics: M:F= 7:2 median age 59.8y (40–76). Most common AEs in the first 3 pts are nausea and chills (100% of patients); fatigue (gr.1–2) and fever (66%; gr. 1–3). Best responses: 3 SD, 1 PR. PK evaluation on both schedules revealed no interaction between INF and MG98. DNMT1 inhibition data will be presented. Conclusions: Combination of INF and MG98 exhibits clinical activity and acceptable safety. [Table: see text]