A multicenter phase 1/2 study investigating the safety, pharmacokinetics, pharmacodynamics and efficacy of a small molecule antimetabolite, RX-3117, plus nab-paclitaxel in pancreatic adenocarcinoma.

Background RX-3117 is an oral small molecule antimetabolite, cyclopentyl pyrimidyl nucleoside that is activated by cancer cells over-expressing uridine cytidine kinase 2 (UCK2). Single agent RX-3117 demonstrated efficacy in a phase I trial in patients with metastatic (met) pancreatic adenocarcinoma (PC). RX-3117 plus nab-paclitaxel (nab-Pac) was evaluated as a first line treatment in met-PC cancer. Methods This was a multicenter open label phase I/II 2-stage study investigating the combination of RX3117 plus nab-Pac in the frontline treatment of patients with met-PC. The phase I portion comprised a dose de-escalation design with primary objectives of determining the safety, tolerability and recommended phase 2 dose (RP2D) of RX-3117 (orally 700, 600, or 500 mg/day for 5 consecutive days with 2 days off/week) plus nab-Pac (intravenous (IV) 125 mg/m2 once weekly) for 3 weeks with 1 week off per a 4-week cycle. The primary objective was to determine the antitumor efficacy. Results 46 patients were enrolled (22 male/24 female; median age 67; 91% Caucasian). The RP2D of RX-3117 plus nab-Pac was 700 mg/day. No dose-limiting toxicities were observed (DLTs). The overall response rate (ORR) was 23.1% and disease control rate (DCR) 74.4%. RX-3117 pharmacokinetics (PK) results were similar to previously reported monotherapy phase 1 trial. All patients experienced a treatment emergent adverse event (TEAE) with the most common diarrhea, nausea, and fatigue.10.9% of patients experienced a serious adverse event (SAE) related to the combination. Conclusion RX-3117 plus nab-Pac in newly diagnosed met-PC patients demonstrated tolerability, safety, and early treatment efficacy.

A phase II study of chloroquinoxaline sulfonamide (CQS) in patients with metastatic colorectal carcinoma (MCRC).

PURPOSE: Phase II multicenter study investigated the efficacy and toxicity of the novel halogenated derivative of sulfaquixonaline Chloroquinoxaline Sulfonamide (CQS) in metastatic colorectal cancer. EXPERIMENTAL DESIGN: Eligible patients with metastatic or recurrent colorectal cancer received CQS at a dose schedule of 2000 mg/m2 over an hour weekly for 4 weeks every 42 days. Treatment was continued until unexpected toxicity or disease progression. RESULTS: A total of seventeen patients were enrolled on this study. 94% of all patients enrolled had prior treatment. Sixteen patients were evaluable for response with fifteen patients showing evidence of disease progression and one patient with prolonged stable disease. One patient had non-evaluable disease. Following this interim analysis, the drug was considered ineffective and the study was terminated early. The most frequent adverse event was anemia. No patients discontinued the treatment because of toxicity. CONCLUSION: CQS, when given at a dose of 2000 mg/m2 weekly for 4 weeks every 42 days to patients with metastatic colorectal cancer, does not result in significant tumor regression.