A phase 2 study of ARQ 501 in combination with gemcitabine in adult patients with treatment naïve, unresectable pancreatic adenocarcinoma

15017

Background: ARQ 501 is a DNA damage checkpoint pathway activator whose effect is to induce selective cell death in cancer cells, independent of the tumor cell’s p53 status. Current evidence implicates a rapid and sustained increase of the pro-apoptotic protein E2F-1 by ARQ 501 as the mechanism of action. Cancer cells are selectively affected due to their pre-existing DNA damage. Induction of E2F-1 in combination with gemcitabine demonstrated potent anti-tumor activity in xenografts of human pancreatic cancer (PACA-2). A recommended phase 2 dose of 400 mg/m2 of ARQ 501 and 800 mg/m2 gemcitabine was identified. Methods: A Phase 2 study in adult patients with treatment naïve, non-resectable adenocarcinoma of the pancreas was initiated to assess the effect of ARQ 501 and gemcitabine on ORR in approximately 66 patients. Cycles consisting of weekly ARQ 501 (400mg/m2) and gemcitabine (800 mg/m2 were repeated every 4 weeks until progression, unacceptable toxicity, or another discontinuation criterion was met. Results: 73 patients were enrolled, with 58 treated to date with at least one infusion. Data is available for 27 patients (16M/11F, median age, 63 years). Of these 27, 5 did not reach a post baseline assessment (3 deaths, 2 PD prior to week 8), 20 are evaluable for response at eight weeks (1 PR, 12 SD of 8–24+ weeks), 7 PD) and 2 have yet to be assessed but are active. Tumor regressions have been observed in 6/20 patients assessed to date. This includes 1 PR, 4 MR (14.3% - 24%) and 1 patient with significant reduction (29.6%) in pancreatic lesions although new superficial liver lesions were observed. Adverse events (N=235) the most common being: anemia (54, 22%), hemolysis (17, 7%), fatigue (15, 6%), edema (7, 3%), and nausea (5, 2%). Conclusions: ARQ 501 has been administered to 58 patients with treatment-naïve, non-resectable adenocarcinoma of the pancreas. Enrollment is complete and early efficacy data is encouraging. A high proportion of patients (13/20) have achieved a minimum SD at the first tumor evaluation. In addition, objective tumor regressions has been observed in this study, providing preliminary confirmation of the utility of induction of E2F-1 in combination with gemcitabine.

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A phase II study of ARQ 501 in patients with advanced squamous cell carcinoma of the head and neck

16509

Background: ARQ 501 is a DNA damage checkpoint pathway activator whose effect is to induce selective cell death in cancer cells, independent of the tumor cell's p53 status. Current evidence implicates a rapid and sustained increase of the pro-apoptotic protein E2F-1 by ARQ 501 as the mechanism of action. Cancer cells are selectively affected due to their pre-existing DNA damage. In initial clinical trials, there was evidence of activity in some patients with head and neck cancer and pre-clinical investigations also supported this application. Therefore, a phase 2 trial is warranted in this patient population. Methods: A phase 2 study in patients with locally advanced, recurrent or metastatic squamous cell carcinoma of the head and neck who had received up to 3 prior systemic therapies was initiated to assess overall response rate, progression free survival at six months, and to further characterize safety. Cycles consist of four weekly administrations of ARQ 501 at a dose of 450 mg/m2. Dose escalation is allowed if a patient successfully completed a full cycle of therapy and had no related grade 2 adverse events. Results: 59 patients have been enrolled to date and 47 have received at least one infusion of ARQ 501. Data is available for 34 patients (27M / 7F, median age, 57 years). Of the 47 patients treated, 11 patients did not reach a post baseline assessment (2 deaths, 8 PD prior to week 8 and 1 withdrew consent). Although at the current date, most patients have not reached their first tumor evaluation, 5 have been assessed for response per RECIST at eight weeks and one patient is demonstrating stable disease. The drug has been well tolerated with the most common adverse event being anemia (11% ) with corresponding edema, fatigue (both 5%), dyspnea (4%), and hyperbilirubinemia (2%). Conclusions: ARQ 501 is well tolerated in patients with advanced, recurrent or persistent squamous cell carcinoma of the head and neck. Enrollment is ongoing and further results will be presented.

No significant financial relationships to disclose.