A Clinical Research Study to Determine Whether PD 0332991 May Be Effective in Treating Patients With Liver Cancer

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third most frequent cause of cancer-related mortality. To date, surgical resection and liver transplantation are considered the main curative treatment options for HCC (El-Serag et al. 2006). However, the majority (\~75%) of patients present with advanced tumor stage and poor liver function, rendering the patient ineligible for surgical interventions. Until the multikinase inhibitor sorafenib (Nexavar) was approved for the treatment of HCC in patients with unresectable disease (disease that can't be removed by surgery), there were no standard systemic therapies, as classical cell killing drugs (administered singularly or in combination) had not led to reproducible response rates or survival benefit. Despite this, response rates to sorafenib are low with overall benefits modest, and moreover the toxicity profile of the drug limits treatment for many patients. There is still a critical need for additional effective drugs to treat advanced HCC. PD-0332991 is an orally available, selective inhibitor of cyclin-dependent kinase 4/6 (CDK4/6), a key regulator of cell growth. Pre-clinical data with PD-0332991 demonstrated potent target-specificity. PD-0332991 demonstrated significant inhibition of tumor cell growth in hepatoma cell lines, as well as animal and xenograft model systems, and was more effective than the currently approved drug, sorafenib in these systems. Initial clinical trials have demonstrated and acceptable toxicity profile for the drug. Thus, PD-0332991 represents an ideal candidate for the treatment of patients with advanced HCC. This trial is an open-label non-randomized single-institution study for subjects with inoperable, recurrent/refractory, advanced hepatocellular carcinoma (HCC). Subjects must have failed or be intolerant of standard first line therapy, sorafenib (Nexavar®). Eligible subjects will receive 125 mg PD-0332991 capsules orally once daily, administered on days 1-21 of a 28-day cycle, in repeated cycles. The primary objective of the study is to assess the time to disease progression (TTP). Secondary objectives include assessment of safety and tolerability, and determination of overall survival (OS) and response rate (RR). Subjects will be permitted to receive protocol directed therapy until disease progression as determined by modified RECIST (Response Evaluation Criteria in Solid Tumors) guidelines or clinical progression, unacceptable toxicity, withdrawal of consent or death. Tumor response assessment will be performed by the Investigator and will consist of evaluation by CT or MRI every 8 weeks. Subjects who discontinue therapy will still be followed for safety on Day 28 (± 3 days), Day 56 (± 3 days) and every 3 months thereafter from the last administration of protocol-directed therapy or until death. Subjects will be continuously assessed for evidence of acute and cumulative toxicity. Vital signs, physical examinations, performance status, laboratory safety tests will be obtained and assessed prior to drug administration at regular intervals throughout the study. Toxicity will be evaluated every 2 weeks during the first 3 cycles and thereafter monthly (once per cycle) by the Investigator according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), Version 4.0.