John Kauh

Safety and Activity of Anti–PD-L1 Antibody in Patients with Advanced Cancer

BACKGROUND Programmed death 1 (PD-1) protein, a T-cell coinhibitory receptor, and one of its ligands, PD-L1, play a pivotal role in the ability of tumor cells to evade the hosts immune system. Blockade of interactions between PD-1 and PD-L1 enhances immune function in vitro and mediates antitumor activity in preclinical models. METHODS In this multicenter phase 1 trial, we administered intravenous anti-PD-L1 antibody (at escalating doses ranging from 0.3 to 10 mg per kilogram of body weight) to patients with selected advanced cancers. Anti-PD-L1 antibody was administered every 14 days in 6-week cycles for up to 16 cycles or until the patient had a complete response or confirmed disease progression. RESULTS As of February 24, 2012, a total of 207 patients--75 with non-small-cell lung cancer, 55 with melanoma, 18 with colorectal cancer, 17 with renal-cell cancer, 17 with ovarian cancer, 14 with pancreatic cancer, 7 with gastric cancer, and 4 with breast cancer--had received anti-PD-L1 antibody. The median duration of therapy was 12 weeks (range, 2 to 111). Grade 3 or 4 toxic effects that investigators considered to be related to treatment occurred in 9% of patients. Among patients with a response that could be evaluated, an objective response (a complete or partial response) was observed in 9 of 52 patients with melanoma, 2 of 17 with renal-cell cancer, 5 of 49 with non-small-cell lung cancer, and 1 of 17 with ovarian cancer. Responses lasted for 1 year or more in 8 of 16 patients with at least 1 year of follow-up. CONCLUSIONS Antibody-mediated blockade of PD-L1 induced durable tumor regression (objective response rate of 6 to 17%) and prolonged stabilization of disease (rates of 12 to 41% at 24 weeks) in patients with advanced cancers, including non-small-cell lung cancer, melanoma, and renal-cell cancer. (Funded by Bristol-Myers Squibb and others; ClinicalTrials.gov number, NCT00729664.).

Multi-Institutional Phase II Study of Selumetinib in Patients With Metastatic Biliary Cancers

PURPOSE Biliary cancers (BCs) carry a poor prognosis, but targeting the RAS/RAF/mitogen-activated protein kinase kinase (MEK)/extracellular signal-related kinase (ERK) pathway is of significance. Selumetinib is an inhibitor of MEK1/2, so this trial was designed to determine the safety and efficacy of selumetinib in BC. PATIENTS AND METHODS This was a multi-institutional phase II study of selumetinib at 100 mg given orally twice per day to patients with advanced BC. The primary end point was response rate. All patients were required to provide tissue before enrolling. The levels of phosphorylated ERK (pERK) and AKT (pAKT) were assessed by immunohistochemistry. Tumors were genotyped for the presence of BRAF- and/or RAS-activating mutations. RESULTS Twenty-eight eligible patients with a median age of 55.6 years were enrolled. Thirty-nine percent of patients had received one prior systemic therapy. Three patients (12%) had a confirmed objective response. Another 17 patients (68%) experienced stable disease (SD), 14 of whom (56%) experienced prolonged SD (> 16 weeks). Patients gained an average nonfluid weight of 8.6 pounds. Median progression-free survival was 3.7 months (95% CI, 3.5 to 4.9) and median overall survival was 9.8 months (95% CI, 5.97 to not available). Toxicities were mild, with rash (90%) and xerostomia (54%) being most frequent. Only one patient experienced grade 4 toxicity (fatigue). All patients had tissue available for analysis. No BRAF V600E mutations were found. Two patients with short-lived SD had KRAS mutations. Absence of pERK staining was associated with lack of response. CONCLUSION Selumetinib displays interesting activity and acceptable tolerability in patients with metastatic BC. Our results warrant further evaluation of selumetinib in patients with metastatic BC.

Comparison of yttrium-90 radioembolization and transcatheter arterial chemoembolization for the treatment of unresectable hepatocellular carcinoma.

PURPOSE To compare the effectiveness and toxicity of transcatheter arterial chemoembolization (chemoembolization) and yttrium-90-labeled microspheres (radioembolization) in patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS Outcomes from patients who underwent radioembolization or chemoembolization as the only treatment for unresectable HCC from 1996 to 2006 were compared. Response was assessed with Response Evaluation Criteria in Solid Tumors, survival was assessed with the Kaplan-Meier method, and toxicity was graded with National Cancer Institute criteria. Multivariate analysis for factors affecting survival was performed. RESULTS Seventy-one patients were treated with either chemoembolization (n = 44, 62%) or radioembolization (n = 27, 38%). Treatment groups were similar in age, sex, Child class, Model for End-Stage Liver Disease score, tumor size, and vascular invasion. Progressive disease at 3 months was observed in 16 (36%) of the 44 patients treated with chemoembolization and nine (33%) of the 27 patients treated with radioembolization (P = not statistically significant). The median overall survival was similar for both groups (6 months with chemoembolization vs 6 months with radioembolization, P= .7). Grade 3 or higher toxicity was observed in 24 of the 71 patients (34%). Tumor multifocality, vascular invasion, and hepatitis C seropositivity were independently associated with worse survival, whereas method of treatment was not. CONCLUSIONS In this single-center study, preliminary evidence suggests that chemoembolization and radioembolization provided similar effectiveness and toxicity in patients with unresectable HCC.

Comparison of conventional transarterial chemoembolization (TACE) and chemoembolization with doxorubicin drug eluting beads (DEB) for unresectable hepatocelluar carcinoma (HCC)

Chemoembolization with doxorubicin drug eluting beads (DEB) is a novel locoregional treatment modality for unresectable hepatocellular carcinoma (HCC). Initial animal studies and clinical trials suggest that treatment with DEB may provide safer and more effective short‐term outcomes than conventional chemoembolization. Current study explores long‐term survival benefits.

Phase II Study of the Mitogen-Activated Protein Kinase 1/2 Inhibitor Selumetinib in Patients With Advanced Hepatocellular Carcinoma

PURPOSE Hepatocellular carcinoma (HCC) is a common and deadly malignancy with few systemic therapy options. The RAF/mitogen-activated protein kinase kinase (MEK)/extracellular signal-related kinase (ERK) pathway is activated in approximately 50% to 60% of HCCs and represents a potential target for therapy. Selumetinib is an orally available inhibitor of MEK tyrosine kinase activity. PATIENTS AND METHODS Patients with locally advanced or metastatic HCC who had not been treated with prior systemic therapy were enrolled on to the study. Patients were treated with selumetinib at its recommended phase II dose of 100 mg twice per day continuously. Cycle length was 21 days. Imaging was performed every two cycles. Biopsies were obtained at baseline and at steady-state in a subset of patients, and pharmacokinetic (PK) analysis was performed on all patients. Results Nineteen patients were enrolled, 17 of whom were evaluable for response. Most (82%) had Child-Pugh A cirrhosis. Toxicity was in line with other studies of selumetinib in noncirrhotic patients. PK parameters were also comparable to those in noncirrhotic patients. No radiographic response was observed in this group, and the study was stopped at the interim analysis. Of 11 patients with elevated α-fetoprotein, three (27%) had decreases of 50% or more. Median time to progression was 8 weeks. Inhibition of ERK phosphorylation was demonstrated by Western blotting. CONCLUSION In this study of selumetinib for patients with HCC, no radiographic responses were seen and time to progression was short, which suggests minimal single-agent activity despite evidence of suppression of target activation.

Modified FOLFIRINOX regimen with improved safety and maintained efficacy in pancreatic adenocarcinoma.

Objectives FOLFIRINOX (5-fluorouracil [5-FU], oxaliplatin, and irinotecan) as compared with gemcitabine in pancreatic cancer (PC) has superior activity and increased toxicity. The bolus 5-FU contributes to the toxicity. We hypothesized that the elimination of bolus 5-FU and use of hematopoietic growth factor will improve the safety profile without compromising the activity of FOLFIRINOX. Methods Sixty patients with PC treated with modified FOLFIRINOX (no bolus 5-FU) were reviewed. Patients were divided into metastatic or nonmetastatic (locally advanced or borderline resectable) disease. Toxicity, response rate, progression-free survival, and overall survival were evaluated. Results Nonmetastatic and metastatic disease were present in 24 (40%) and 36 (60%) patients, respectively. The incidence of grade 4 neutropenia, grade 3/4 diarrhea, and fatigue were 3%, 13%, and 13%, respectively. Response rate was 30%. The median progression-free survival for nonmetastatic disease was 13.7 months (95% confidence interval [CI], 9.6–24.6 months), and that for metastatic disease was 8.5 months (95% CI, 3.7–11.0 months), respectively. The median overall survival for nonmetastatic disease was 17.8 months (95% CI, 9.9 months to not estimable), and that for metastatic disease was and 9.0 months (95% CI, 7.1 months to not estimable), respectively. Conclusions Modified FOLFIRINOX has an improved safety profile with maintained efficacy in metastatic PC. Modified FOLFIRINOX has promising activity in nonmetastatic disease.

Overcoming mTOR inhibition-induced paradoxical activation of survival signaling pathways enhances mTOR inhibitors’ anticancer efficacy

The mammalian target of rapamycin (mTOR) has emerged as an important cancer therapeutic target. Several mTOR inhibitors are currently being tested in cancer clinical trials. Both PI3K/Akt and MEK/ERK signaling regulate mTOR axis. However, inhibition of mTOR activates Akt survival signaling, which in turn attenuates mTOR inhibitors’ anticancer efficacy. We are interested in developing strategies for enhancing mTOR-targeted cancer therapy. In this study, we report that mTOR inhibition also induced activations of the MEK/ERK signaling pathway in some cancer cell lines after a prolonged treatment. The combination of rapamycin with the MEK inhibitor U0126 significantly enhanced growth inhibitory effects of cancer cells, suggesting that MEK/ERK activation may counteract mTOR inhibitors’ anticancer efficacy. Similarly, the combination of an mTOR inhibitor with the EGF receptor inhibitor erlotinib synergistically inhibited the growth of both human cancer cells in cell cultures and xenografts in nude mice. Moreover, the presence of erlotinib suppressed rapamycin-induced phosphorylation of Akt, ERK and eIF4E as well, implying that erlotinib can suppress mTOR inhibition-induced feedback activation of several survival signaling pathways including Akt, ERK and eIF4E. Thus, we suggest a therapeutic strategy for enhancing mTOR-targeted cancer therapy by preventing mTOR inhibition-induced feedback activation of several survival mechanisms.

Examining Racial Disparities in Colorectal Cancer Care

African Americans are disproportionately burdened with colorectal cancer. Although incidence and mortality rates have declined in the past two decades, the disparity in health outcomes has progressively increased. This comprehensive review examines the existing literature regarding racial disparities in colorectal cancer screening, stage at diagnosis, and treatment to determine if differences exist in the quality of care delivered to African Americans. A comprehensive review of relevant literature was performed. Two databases (EBSCOHOST Academic Search Premier and Scopus) were searched from 2000 to 2007. Articles that assessed racial disparities in colorectal cancer screening, stage of disease at diagnosis, and treatment were selected. The majority of studies identified examined colorectal cancer screening outcomes. Although racial disparities in screening have diminished in recent years, African American men and women continue to have higher colorectal cancer incidence and mortality rates and are diagnosed at more advanced stages. Several studies regarding stage of disease at diagnosis identified socioeconomic status (SES) and health insurance status as major determinants of disparity. However, some studies found significant racial disparities even after controlling for these factors. Racial disparities in treatment were also found at various diagnostic stages. Many factors affecting disparities between African Americans and Whites in colorectal cancer incidence and mortality remain unexplained. Although the importance of tumor biology, genetics, and lifestyle risk factors have been established, prime sociodemographic factors need further examination to understand variances in the care of African Americans diagnosed with colorectal cancer.

Fractionated radioimmunotherapy with 90Y-clivatuzumab tetraxetan and low-dose gemcitabine is active in advanced pancreatic cancer: A phase 1 trial

It has been demonstrated that the humanized clivatuzumab tetraxetan (hPAM4) antibody targets pancreatic ductal carcinoma selectively. After a trial of radioimmunotherapy that determined the maximum tolerated dose of single‐dose yttrium‐90‐labeled hPAM4 (90Y‐hPAM4) and produced objective responses in patients with advanced pancreatic ductal carcinoma, the authors studied fractionated radioimmunotherapy combined with low‐dose gemcitabine in this disease.

Phosphorylated Eukaryotic Translation Initiation Factor 4 (eIF4E) is Elevated in Human Cancer Tissues

Eukaryotic translation initiation factor 4E (eIF4E) is a rate-limiting factor for cap-dependent protein synthesis and is regulated by PI3 kinase/mTOR and mitogen-activated protein kinase (MAPK)/Mnk signaling pathways. Recent studies have shown that Mnk-mediated eIF4E phosphorylation is absolutely required for eIF4E’s oncogenic function. Overexpression of eIF4E has been reported in many types of cancers; however, the expression of phosphorylated eIF4E (p-eIF4E) in human cancer tissues, particularly solid tumor tissues, has not been reported. The current study focused on evaluating p-eIF4E expression patterns in the tumor tissues obtained from patients with a variety of malignancies. Using three different tissue microarrays consisting of a total of 380 cases of human cancers and 146 cases of adjacent normal tissues, we detected p-eIF4E positive staining in 63.4% (241/380) of cancers, but only in 30.1% (44/146) of adjacent normal tissues. Thus, p-eIF4E expression is significantly higher in cancers than in adjacent normal tissues (P < 0.001). In general, there was no major difference in p-eIF4E staining between cancers with and without lymph node metastasis. In certain types of maligancies such as lung, gastric and colorectal cancers, p-eIF4E staining was significantly higher in the early stage (T1) than in the late stage (T3) disease (P < 0.05). Collectively, these findings suggest that p-eIF4E may play a critical role in cancer development, particularly early stages of tumorigenesis and support p-eIF4E as a good cancer therapeutic target.