The recommended dose for disease-directed studies of OSI-774 administered orally on a daily, continuous, uninterrupted schedule is 150 mg/d. OSI-774 was well tolerated, and several patients with epidermoid malignancies demonstrated either antitumor activity or relatively long periods of stable disease. The precise contribution of OSI-774 to these effects is not known.

PurposeWe assessed the safety and antitumor activity of avelumab, a fully human anti–programmed death-ligand 1 (PD-L1) IgG1 antibody, in patients with refractory metastatic urothelial carcinoma.MethodsIn this phase Ib, multicenter, expansion cohort, patients with urothelial carcinoma progressing after platinum-based chemotherapy and unselected for PD-L1 expression received avelumab 10 mg/kg intravenously every 2 weeks. The primary objectives were safety and tolerability. Secondary objectives included confirmed objective response rate (Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1), progression-free survival, overall survival (OS), and PD-L1–associated clinical activity. PD-L1 positivity was defined as expression by immunohistochemistry on ≥ 5% of tumor cells.ResultsForty-four patients were treated with avelumab and followed for a median of 16.5 months (interquartile range, 15.8 to 16.7 months). The data cutoff was March 19, 2016. The most frequent treatment-related adverse events of any grade were fatigue/asthenia (31.8%), infusion-related reaction (20.5%), and nausea (11.4%). Grades 3 to 4 treatment-related adverse events occurred in three patients (6.8%) and included asthenia, AST elevation, creatine phosphokinase elevation, and decreased appetite. The confirmed objective response rate by independent central review was 18.2% (95% CI, 8.2% to 32.7%; five complete responses and three partial responses). The median duration of response was not reached (95% CI, 12.1 weeks to not estimable), and responses were ongoing in six patients (75.0%), including four of five complete responses. Seven of eight responding patients had PD-L1–positive tumors. The median progression-free survival was 11.6 weeks (95% CI, 6.1 to 17.4 weeks); the median OS was 13.7 months (95% CI, 8.5 months to not estimable), with a 12-month OS rate of 54.3% (95% CI, 37.9% to 68.1%).ConclusionAvelumab was well tolerated and associated with durable responses and prolonged survival in patients with refractory metastatic UC.

Merck KGaA, and Pfizer Inc.

Rigorous quality control steps, termed checkpoints, tightly regulate progression through the cell cycle. DNA-damaging chemotherapy and radiation activate functional cellular checkpoints. These checkpoints can facilitate DNA repair and promote cell death in unrepaired cells. There are at least three DNA damage checkpoints -at G1/S, S, and G2/M -as well as a mitotic spindle checkpoint. Most cancer cells harbour mutations in tumour suppressors and/or oncogenes, which impair certain cell checkpoints. Inhibiting the remaining cell checkpoints -particularly after exposure of cancer cells to chemotherapy and/or radiation -allows cell death, a strategy now being employed in cancer therapeutics. With our increasing knowledge of cell cycle regulation, many compounds have been developed to inhibit specific checkpoint components, particularly at the G2/M transition. One such target is checkpoint kinase-1 (Chk1). We review here the molecular framework of the cell cycle, the rationale for targeting Chk1, the preclinical concepts related to the development of Chk1 inhibitors, and the efficacy and safety results from Chk1 inhibitors now in phase I/II trials. British Journal of Cancer (2008) The cell cycle is organised into a series of dependent pathways, whereby the initiation of each event is dependent upon successful completion of previous events. In this way, replicating cells traverse the four distinct phases of the cell cycle consecutively: G1 followed by S, followed by G2 and, finally, M. This ordered progression is guarded by checkpoints capable of delaying the cell cycle in response to intra-or extracellular stressors. As part of the cell cycle surveillance system, the DNA damage and spindle checkpoints protect the cell from genomic instability. Checkpoints are important quality control measures that ensure the proper sequence of cell cycle events and allow cells to respond to DNA damage.Increasingly, checkpoint inhibition has become an area of novel drug development. In the setting of DNA damage, checkpoint inhibition leads to genomic instability, and subsequent cell death. The first checkpoint, found at the G1/S transition, is compromised in many malignant cells, due to mutations in various tumour suppressor genes, including retinoblastoma protein (Rb) and p53. Cells deficient in the G1 checkpoint are dependent on the S and G2 checkpoints for DNA repair. Checkpoint kinase-1 (Chk1) is an active transducer kinase at both the S and G2 checkpoints, rendering it a target for rational anticancer drug development. In the presence of DNA damage, Chk1 inactivation abrogates G2 arrest, resulting in preferential cancer cell death .This article serves to review the (1) current molecular pathways comprising the cell cycle checkpoint machinery, (2) inhibition of Chk1 as an effective means of abrogating G2 arrest, and (3) current Chk1 inhibitors in use in phase I clinical trials.

Orthotopic liver transplantation (OLT) can be a definitive treatment for patients with hepatocellular carcinoma (HCC).

Purpose: MAPK and PI3K/AKT/mTOR pathways play important roles in many tumors. In this study, safety, antitumor activity, and pharmacokinetics of buparlisib (pan class PI3K inhibitor) and trametinib (MEK inhibitor) were evaluated.Experimental Design: This open-label, dose-finding, phase Ib study comprised dose escalation, followed by expansion part in patients with RAS-or BRAF-mutant non-small cell lung, ovarian, or pancreatic cancer.Results: Of note, 113 patients were enrolled, 66 and 47 in doseescalation and -expansion parts, respectively. MTD was established as buparlisib 70 mg þ trametinib 1.5 mg daily [5/15, 33% patients with dose-limiting toxicities (DLT)] and recommended phase II dose (RP2D) buparlisib 60 mg þ trametinib 1.5 mg daily (1/10, 10% patients with DLTs). DLTs included stomatitis (8/103, 8%), diarrhea, dysphagia, and creatine kinase (CK) increase (2/103, 2% each). Treatment-related grade 3/4 adverse events (AEs) occurred in 73 patients (65%); mainly CK increase, stomatitis, AST/ALT (aspartate aminotransferase/alanine aminotransferase) increase, and rash. For all (21) patients with ovarian cancer, overall response rate was 29% [1 complete response, 5 partial responses (PR)], disease control rate 76%, and median progression-free survival was 7 months. Minimal activity was observed in patients with non-small cell lung cancer (1/17 PR) and pancreatic cancer (best overall response was SD). Relative to historical data, buparlisib exposure increased and trametinib exposure slightly increased with the combination.Conclusions: At RP2D, buparlisib 60 mg þ trametinib 1.5 mg daily shows promising antitumor activity for patients with KRAS-mutant ovarian cancer. Long-term tolerability of the combination at RP2D is challenging, due to frequent dose interruptions and reductions for toxicity.

The PI3K/AKT/mTOR and RAS/RAF/MEK/ERK pathways are two of the most frequently dysregulated kinase cascades in human cancer. Molecular alterations in these pathways are implicated in tumorigenesis and resistance to anticancer therapies. The PI3K/AKT/mTOR and RAS/RAF/MEK/ERK pathways are known to interact with each other at several nodes, and mounting evidence suggests that dual blockade of both pathways may be required to achieve anticancer effects in certain contexts. This may include tumor types with a high frequency of RAS/RAF/MEK/ERK pathway activation, or situations in which dual pathway strategies may be required to overcome resistance to current targeted therapies. Several clinical studies are currently evaluating the combination of PI3K and MEK inhibitors in a variety of different cancers with certain types of molecular alterations. This review will summarize existing knowledge of the PI3K/AKT/mTOR and RAS/RAF/MEK/ERK pathways, the cross-talk between them, and the current generation of PI3K and MEK inhibitors that target them. The preclinical rationale for dual pathway inhibition will be discussed within the context of the major tumor types currently being explored in ongoing clinical trials, namely malignant melanoma with BRAF or NRAS mutations, and colorectal, ovarian, pancreatic, and basal-like breast cancers. The emerging clinical profile of PI3K and MEK inhibitor combinations, as reported in Phase I trials, will also be discussed.

Purpose: PF299804 is a potent, orally available, irreversible inhibitor of tyrosine kinase human epidermal growth factor receptors (HER) 1 (EGFR), HER2, and HER4. This first-in-human study investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of PF299804 in patients with advanced solid malignancies. Experimental Design: PF299804 was administered once daily continuously (schedule A) and intermittently (schedule B). Dose escalation proceeded until intolerable toxicities occurred. Skin biopsies were taken predose and after 14 days of treatment to establish a pharmacokinetic/pharmacodynamic relationship. Tumor response was measured once every 2 cycles. Efficacy was correlated with tumor genotypes in non–small cell lung cancer (NSCLC) patients. Results: 121 patients were included (111 in schedule A, 10 in schedule B). The maximum tolerated dose (MTD) was 45 mg/d. Dose-limiting toxicities included stomatitis and skin toxicities. Most adverse events were mild and comprised skin toxicities, fatigue, and gastrointestinal side-effects including diarrhea, nausea, and vomiting. Pharmacokinetic analyses revealed dose-dependent increases in PF299804 exposure associated with target inhibition in skin biopsy samples. Fifty-seven patients with non–small cell lung cancer (NSCLC) were treated in this study. Four patients, all previously treated with gefitinib or erlotinib (2 with exon 19 deletions, 1 with exon 20 insertion, 1 mutational status unknown), had a partial response to PF299804. Conclusions: The MTD of PF299804 is 45 mg/d. Both continuous and intermittent treatment schedules were well tolerated, and encouraging signs of antitumor activity were observed in gefitinib/erlotinib treated NSCLC patients. Clin Cancer Res; 17(5); 1131–9. ©2011 AACR.