A non-randomized phase II study of sequential irinotecan (CPT) and flavopiridol (F) in patients (pts) with advanced hepatocellular carcinoma (HCC)

4148 Background: F is a CDK inhibitor which potentiates CPT- induced apoptosis. In a phase I trial of CPT 100mg/m2 followed 7 hours later by F given over 1 hour weekly for 4 out of 6 weeks (Shah, Clin Can Res 2005), 2 pts with advanced HCC had stable disease (SD) for 14+ months. In the same phase I study, patients who were p53 wild-type (negative p53 staining), and whose p21 remained stable or was non-detectable on the post-treatment biopsy, were noted to have SD or a partial response. Methods: Pts with advanced HCC, no prior systemic therapy, Child’s-Pugh score A, B7 or B8, and KPS ≥ 70%, received 100 mg/m2 of CPT, followed 7 hours later by 60 mg/m2 of F over 1 hour weekly for 4 out of 6 weeks. The trial had a two stage design, with a planned accrual of 30 pts. The primary endpoint was TTP. Tumor response was assessed every 2 cycles using revised WHO criteria. p53 immuno-staining was performed on pre-treatment paraffin preserved tissues. A cut-off of 20% defined positive mutant versus negative wild-type p53 status. Results: 16 pts were enrolled: median age 64 (range 26–84), KPS 80% (70–90%), and 10 males/6 females. 13 pts received therapy, two progressed before starting, and one patient (pt) was excluded because pathology re-review did not confirm HCC. 1 pt was excluded because of consent withdrawal after first dose of therapy. This pt was included in the toxicity analysis. The median number of cycles given was 2 (range 1–8 cycles). Grade 3 and 4 toxicities included dehydration (4: 30%) diarrhea (2: 15%) febrile neutropenia (6: 46% - 4 events in one pt) and fatigue/weakness (3: 23%). Therapy had to be discontinued in 2 pts because of toxicity. TTP was 2.6 months (95% CI 2.43–8.42). One patient had SD for over a year, 8 had progression of disease (POD), and 4 came off study because of toxicity. Mutational p53 was evaluated in 7 pts. The pt with SD had wild type p53. Three pts with POD had mutant p53, while the other 3 had wild type 53. Conclusions: CPT followed by F is an ineffective therapy for HCC. This therapy was relatively poorly tolerated, likely contributed to by underlying cirrhosis in HCC, but similar to our experience of CPT in HCC. While p21 level pre and post therapy is lacking, the wild type p53 of the patient with SD maybe a predictor of response in HCC where p53 mutations are common. No significant financial relationships to disclose.