Association Between Serum Folate Level and Toxicity of Capecitabine During Treatment for Colorectal Cancer.

BACKGROUND: Folate level was proposed to be a predictor for fluoropyrimidine-related toxicity. We conducted a prospective study to determine the association between serum and red-cell folate and capecitabine-related toxicity in patients with colorectal cancers. MATERIALS AND METHODS: Eligibility criteria included diagnosis of colorectal cancers; eligible patients who were scheduled to undergo capecitabine monotherapy or capecitabine-oxaliplatin (CAPOX) for adjuvant or palliative purposes. Exclusion criteria included concomitant radiotherapy or chemotherapy other than capecitabine or CAPOX and creatinine clearance <30 mL/min. Fasting serum and red-cell folate were measured prior to chemotherapy. Capecitabine was administered at 2,500 mg/m2 per day (monotherapy) or 2,000 mg/m2 per day (CAPOX) for 14 days every 3 weeks. The toxicity of the first four cycles was documented by clinical investigators who were blinded to folate levels. RESULTS: A total of 144 patients were recruited, of whom 126 were eligible; 40 patients had capecitabine alone, and 86 patients received CAPOX. The rates of grade 2 and grade 3 toxicity were 63.5% and 14.3%, respectively. Nausea and vomiting were the most common grade ≥2 adverse event (47.7%), followed by hand-foot syndrome (25.4%), diarrhea (23.1%), and neutropenia (22.3%). Combination with oxaliplatin (odds ratio [OR], 2.77; p = .043) and serum folate (OR, 10.33; p = .002) were independent predictors of grade ≥2 toxicity. Red-cell folate was not predictive of toxicity. For every 10 nmol/L increment in serum folate, the risk of grade ≥2 toxicity increased by 9%. CONCLUSION: Serum folate level, but not red-cell folate, was associated with higher rate of grade ≥2 toxicity during capecitabine-based treatment. Excessive folate intake may be avoided before and during capecitabine-based chemotherapy. IMPLICATIONS FOR PRACTICE: This is the first prospective study to evaluate the association between serum folate level and capecitabine-related toxicity in patients with colon cancers. It shows that higher serum folate level is associated with increased risks of moderate to severe toxicity during capecitabine-based treatment. Excessive folate intake should be avoided before and during capecitabine-based chemotherapy.

Preclinical evaluation of the PI3K-mTOR dual inhibitor PF-04691502 as a novel therapeutic drug in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is common in Southeast Asia and over 40% of NPC tissues have PIK3CA amplification. This study characterized the preclinical activity of a novel potent dual PI3K/mTOR inhibitor, PF-04691502, in five NPC cell lines: CNE-1, HK1, CNE-2, HONE-1 and C666-1, in which all of the cell lines possessed basal and activated expression of Akt and p70S6K. Over 80% inhibition of cell growth in all of these cell lines were achieved after 72 h of PF-04691502 incubation and their IC50 were in hundred nanomolar range. CNE-2, HK1 and HONE-1 were selected to further evaluate the effect of PF-04691502 on cell cycle, apoptosis and Akt downstream signaling. PF-04691502 induced G0/G1 cell cycle arrest and apoptosis at 24 h incubation and it significantly abrogated Akt and its downstream signaling by suppressing the expression of p-mTOR, p-p70S6K, p-Akt(S473, T308), p-S6 and p-4E-BP1, suggesting its effectiveness in inhibition of translation and protein synthesis. Anti-proliferation was also observed in 3D culture system and spheroids formation of NPC cell line HONE-1-EBV was strongly inhibited by PF-04691502. Antitumor activity was observed in CNE-2 xenograft in 2 weeks of 10 mg/kg PF-09641502 treatment to tumor bearing athymic nude mice. Both tumor volume and weight in treatment group were significantly lower than those in vehicle group while no obvious body weight decrease was found, suggesting this working dose was effective and well-tolerated. Additive effects were observed in combination of PF-09641502 with either cisplatin or paclitaxel. There were no synergistic effect observed in drug combination but PF-09641502 alone was effective in treating cisplatin resistant cell lines as compared to its parental control. The beneficial effects of PF-09641502 in both in vitro and in vivo studies for NPC warrant a further investigation.

Management of hepatocellular carcinoma: beyond sorafenib.

The positive results of sorafenib have unveiled a new direction of research in the management of hepatocellular carcinoma (HCC). Since then intensive efforts have been focused on development of novel management strategy to further improve the outcome for patients with HCC. Emerging data have suggested that tumor progression of HCC is driven by a number of deregulated signaling pathways and/or epigenetic mechanism. Thus much effort is dedicated to identification of novel agents targeting these dysregulated pathways. Combinations of targeted therapeutics and transarterial chemoembolization (TACE), or different systemic therapeutics also hold the promise to improve treatment outcome beyond sorafenib. This review aims to summarize the current status of clinical development of treatment in HCC. Perspectives on future direction of research will also be discussed.

Clinical trial designs for targeted agents.

With an increasing number of targeted agents available for testing, clinical trials must be rationally designed based on sound knowledge of the molecular mechanisms linking target and disease, fortified by strong preclinical data demonstrating how this relationship is modified by the targeted agent. Patients and resources are precious and should be expended judiciously on clinical trials that are well planned. Although traditional trial designs and endpoints may not be adequate for developing contemporary targeted drugs, transiting directly from phase I to phase III testing should be avoided except in distinct circumstances. Increased research efforts should be spent on the prospective evaluation and validation of novel biologic endpoints and innovative clinical designs, such that promising targeted agents can be effectively developed to benefit the care of cancer patients.