Smitha S. Krishnamurthi

Expression of Epiregulin and Amphiregulin and K-ras Mutation Status Predict Disease Control in Metastatic Colorectal Cancer Patients Treated With Cetuximab

PURPOSE The antiepidermal growth factor receptor (EGFR) antibody cetuximab shows activity in multiple epithelial tumor types; however, responses are seen in only a subset of patients. This study was conducted to identify markers that are associated with disease control in patients treated with cetuximab. PATIENTS AND METHODS One hundred ten patients with metastatic colorectal cancer were enrolled onto a cetuximab monotherapy trial. Transcriptional profiling was conducted on RNA from mandatory pretreatment metastatic biopsies to identify genes whose expression correlates with best clinical responses. EGFR and K-ras mutation analyses and EGFR gene copy number analyses were performed on DNA from pretreatment biopsies. RESULTS Gene expression profiles showed that patients with tumors that express high levels of the EGFR ligands epiregulin and amphiregulin are more likely to have disease control with cetuximab (EREG, P = .000015; AREG, P = .000025). Additionally, patients whose tumors do not have K-ras mutations have a significantly higher disease control rate than patients with K-ras mutations (P = .0003). Furthermore, patients with tumors that have high expression of EREG or AREG also have significantly longer progression-free survival (PFS) than patients with low expression (EREG: P = .0002, hazard ratio [HR] = 0.47, and median PFS, 103.5 v 57 days, respectively; AREG: P < .0001, HR = 0.44, and median PFS, 115.5 v 57 days, respectively). CONCLUSION Patients with tumors that have high gene expression levels of epiregulin and amphiregulin and patients with wild-type K-ras are more likely to have disease control on cetuximab treatment. The identified markers could be developed further to select patients for cetuximab therapy.

Phase I Pharmacokinetic and Pharmacodynamic Study of the Oral MAPK/ERK Kinase Inhibitor PD-0325901 in Patients with Advanced Cancers

Purpose: To determine tolerability, pharmacokinetics, and pharmacodynamics of PD-0325901, a highly potent, selective, oral mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase 1/2 inhibitor in advanced cancer patients. Experimental Design: Sixty-six patients received PD-0325901 at doses from 1 mg once daily to 30 mg twice daily (BID). Cycles were 28 days; three administration schedules were evaluated. Pharmacokinetic parameters were assessed and tumor biopsies were done to evaluate pharmacodynamics. Results: Common adverse events were rash, diarrhea, fatigue, nausea, and visual disturbances including retinal vein occlusion (RVO; n = 3). Neurotoxicity was frequent in patients receiving ≥15 mg BID. The maximum tolerated dose, 15 mg BID continuously, was associated with late-onset RVO outside the dose-limiting toxicity window. An alternative dose and schedule, 10 mg BID 5 days on/2 days off, was therefore expanded; one RVO event occurred. Three of 48 evaluable patients with melanoma achieved confirmed partial responses; 10 had stable disease ≥4 months. PD-0325901 exposure was generally dose proportional. Doses ≥2 mg BID consistently caused ≥60% suppression of phosphorylated ERK in melanoma. Fifteen patients showed significant decreases (≥50%) in Ki-67. Conclusions: PD-0325901 showed preliminary clinical activity. The maximum tolerated dose, based on first cycle dose-limiting toxicities, was 15 mg BID continuously. However, 10 and 15 mg BID continuous dosing and 10 mg BID 5 days on/2 days off schedules were associated with delayed development of RVO; thus, further enrollment to this trial was stopped. Intermittent dose scheduling between 2 and 10 mg BID should be explored to identify a recommended dose with long-term PD-0325901 use. Clin Cancer Res; 16(6); 1924–37

Colon cancer, version 1.2017: Clinical practice guidelines in oncology

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Bladder Cancer focuses on systemic therapy for muscle-invasive urothelial bladder cancer, as substantial revisions were made in the 2017 updates, such as new recommendations for nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab. The complete version of the NCCN Guidelines for Bladder Cancer addresses additional aspects of the management of bladder cancer, including non-muscle-invasive urothelial bladder cancer and nonurothelial histologies, as well as staging, evaluation, and follow-up.

Phase I Study of Bosutinib, a Src/Abl Tyrosine Kinase Inhibitor, Administered to Patients with Advanced Solid Tumors

Purpose: Bosutinib, a potent ATP-competitive, quinolinecarbonitrile Src/Abl kinase inhibitor, was tested in this first-in-human phase I trial in patients with advanced solid tumor malignancies. Patients and Methods: This trial was conducted in 2 parts. In part 1 (dose escalation), increasing oral bosutinib doses were administered using a 3 + 3 design. In part 2 (dose expansion), approximately 30 patients each with refractory colorectal, pancreas, or non–small cell lung cancer were treated at the recommended phase II dose (RP2D). Primary efficacy endpoints for part 2 were median progression-free survival (colorectal and non–small cell lung) and median overall survival (pancreas). Results: In part 1, dose-limiting toxicities of grade 3 diarrhea (two patients) and grade 3 rash occurred with bosutinib 600 mg/day and the maximum tolerated dose identified was 500 mg/day. However, the majority of patients treated with 500 mg/day had grade 2 or greater gastrointestinal toxicity, and 400 mg/day was identified as the RP2D. The most common bosutinib-related adverse events were nausea (60% patients), diarrhea (47%), vomiting (40%), fatigue (38%), and anorexia (36%). Bosutinib had a mean half-life of 19 to 20 hours at the RP2D. A partial response (breast) and unconfirmed complete response (pancreas) were observed; 8 of 112 evaluable patients had stable disease for 22 to 101 weeks. However, the primary efficacy endpoints for part 2 were not met. Conclusions: Bosutinib was generally well tolerated in patients with solid tumors, with the main toxicity being gastrointestinal. The RP2D was 400 mg/day orally. Further study of bosutinib is planned in combination regimens. Clin Cancer Res; 18(4); 1092–100. ©2011 AACR.

Randomized Multicenter Phase II Study of Modified Docetaxel, Cisplatin, and Fluorouracil (DCF) Versus DCF Plus Growth Factor Support in Patients With Metastatic Gastric Adenocarcinoma: A Study of the US Gastric Cancer Consortium

PURPOSE Docetaxel, cisplatin, and fluorouracil (DCF) is a standard first-line three-drug chemotherapy regimen for advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma and is associated with significant toxicity. We examined the safety and efficacy of a modified DCF (mDCF) regimen in a randomized multicenter phase II study. PATIENTS AND METHODS Previously untreated patients with metastatic gastric or GEJ adenocarcinoma were randomly assigned to receive either mDCF (fluorouracil 2,000 mg/m2 intravenously [IV] over 48 hours, docetaxel 40 mg/m2 IV on day 1, cisplatin 40 mg/m2 IV on day 3, every 2 weeks) or parent DCF (docetaxel 75 mg/m2, cisplatin 75 mg/m2, and fluorouracil 750 mg/m2 IV over 5 days with granulocyte colony-stimulating factor, every 3 weeks). The study had 90% power to differentiate between 6-month progression-free survival of 26% and 43%, with type I and II error rates of 10% each. An early stopping rule for toxicity was included, defined as grade 3 to 4 adverse event rate > 70% in the first 3 months. RESULTS From November 2006 to June 2010, 85 evaluable patients were enrolled (male, n = 61; female, n = 24; median age, 58 years; Karnofsky performance status, 90%; GEJ, n = 28; gastric, 57). mDCF (n = 54) toxicity rates included 54% grade 3 to 4 toxicity (22% hospitalized) within the first 3 months and 76% grade 3 to 4 toxicity over the course of treatment. The DCF arm (n = 31) closed early because of toxicity, with rates of 71% grade 3 to 4 toxicity (52% hospitalized) within 3 months and 90% grade 3 to 4 toxicity over the course of treatment. Six-month PFS was 63% (95% CI, 48% to 75%) for mDCF and 53% (95% CI, 34% to 69%) for DCF. Median overall survival was improved for mDCF (18.8 v 12.6 months; P = .007). CONCLUSION mDCF is less toxic than parent DCF, even when supported with growth factors, and is associated with improved efficacy. mDCF should be considered a standard first-line option for patients with metastatic gastric or GEJ adenocarcinoma.

Phase II Study of Dasatinib (BMS-354825) in Patients With Metastatic Adenocarcinoma of the Pancreas

BACKGROUND Src, EphA2, and platelet-derived growth factor receptors α and β are dysregulated in pancreatic ductal adenocarcinoma (PDAC). METHODS Dasatinib is an oral multitarget tyrosine kinase inhibitor that targets BCR-ABL, c-Src, c-KIT, platelet-derived growth factor receptor β, and EphA2. We conducted a phase II, single-arm study of dasatinib as first-line therapy in patients with metastatic PDAC. METHODS Dasatinib (100 mg twice a day, later reduced to 70 mg twice a day because of toxicities) was orally administered continuously on a 28-day cycle. The primary endpoint was overall survival (OS). Response was measured using the Response Evaluation Criteria in Solid Tumors. Circulating tumor cells (CTCs) were also collected. RESULTS Fifty-one patients enrolled in this study. The median OS was 4.7 months (95% confidence interval [CI]: 2.8-6.9 months). Median progression-free survival was 2.1 months (95% CI: 1.6-3.2 months). In 34 evaluable patients, the best response achieved was stable disease in 10 patients (29.4%). One patient had stable disease while on treatment for 20 months. The most common nonhematologic toxicities were fatigue and nausea. Edema and pleural effusions occurred in 29% and 6% of patients, respectively. The number of CTCs did not correlate with survival. CONCLUSION Single-agent dasatinib does not have clinical activity in metastatic PDAC.

Comparison of hybrid FDG PET/MRI compared with PET/CT in colorectal cancer staging and restaging: a pilot study

PurposeWe report our initial clinical experience from a pilot study to compare the diagnostic accuracy of hybrid PET/MRI with PET/CT in colorectal cancer and discuss potential PET/MRI workflow solutions for colorectal cancer.MethodsPatients underwent both FDG PET/CT and PET/MRI (Ingenuity TF PET/MRI, Philips Healthcare) for rectal cancer staging or colorectal cancer restaging. The PET acquisition of PET/MRI was similar to that of PET/CT whereas the MRI protocol was selected individually based on the patient’s medical history. One nuclear medicine physician reviewed the PET/CT studies and one radiologist reviewed the PET/MRI studies independently. The diagnostic accuracy of each modality was determined in consensus, using available medical records as a reference.ResultsOf the 12 patients enrolled, two were for initial staging and ten for restaging. The median scan delay between the two modalities was 60 min. The initial imaging was PET/CT in nine patients and PET/MRI in three patients. When PET/CT was performed first, the SUV values of the 16 FDG avid lesions were greater at PET/MRI than at PET/CT. In contrast, when PET/MRI was performed first, the SUV values of the seven FDG avid lesions were greater at PET/CT than at PET/MRI. PET/MRI provided more detailed T staging than PET/CT. On a per-patient basis, with both patient groups combined for the evaluation of N and M staging/restaging, the true positive rate was 5/7 (71%) for PET/CT and 6/7 (86%) for PET/MRI, and true negative rate was 5/5 (100%) for both modalities. On a per-lesion basis, PET/CT identified 26 of 29 (90%) tumor lesions that were correctly detected by PET/MRI. Our proposed workflow allows for comprehensive cancer staging including integrated local and whole-body assessment.ConclusionsOur initial experience shows a high diagnostic accuracy of PET/MRI in T staging of rectal cancer compared with PET/CT. In addition, PET/MRI shows at least comparable accuracy in N and M staging as well as restaging to PET/CT. However, the small sample size limits the generalizability of the results. It is expected that PET/MRI would yield higher diagnostic accuracy than PET/CT considering the high soft tissue contrast provided by MRI compared with CT, but larger studies are necessary to fully assess the benefit of PET/MRI in colorectal cancer.

Phase I trial of docetaxel and thalidomide: a regimen based on metronomic therapeutic principles

SummaryPurpose: Pre-clinical models have demonstrated the benefit of metronomic schedules of cytotoxic chemotherapy combined with anti-angiogenic compounds. This trial was undertaken to determine the toxicity of a low dose regimen using docetaxel and thalidomide. Patients and Methods: Patients with advanced solid tumors were enrolled. Thalidomide 100mg twice daily was given with escalating doses of docetaxel from 10 to 30mg/m2/week. One cycle consisted of 12 consecutive weeks of therapy. The maximal tolerated dose (MTD) was defined as the dose of thalidomide along with docetaxel that caused ≤grade 1 non-hematologic or ≤grade 2 hematologic toxicity for cycle one. Results: Twenty-six patients were enrolled. Dose-limiting toxicities (DLTs) were bradycardia, fatigue, fever, hyperbilirubinemia, leukopenia, myocardial infarction, and neutropenia. Prolonged freedom from disease progression was observed in 44.4% of the evaluable patients. Conclusions: This anti-angiogenic regimen was well tolerated and demonstrated clinical benefit. The recommended phase II dosing schedule is thalidomide 100mg twice daily with docetaxel 25mg/m2/week.

A multicenter phase II study of "adjuvant" irinotecan following resection of colorectal hepatic metastases.

Objectives:This study evaluates the efficacy and toxicity of single-agent irinotecan following hepatectomy for metachronous colorectal metastases, and examines the predictive value of p27 and p53 expression and of microsatellite instability (MSI) status. Methods:Twenty-nine patients, previously treated with 5-fluorouracil, with operable hepatic colorectal metastases underwent hepatectomy and received adjuvant irinotecan (thrice weekly) for 6 planned cycles. Metastases were examined for p53 and p27 expression by immunohistochemistry and for MSI using mono- and dinucleotide markers. Results:The starting dose of irinotecan was 350 mg/m2 (in 3 patients), 300 mg/m2 (n = 14), and 250 mg/m2 (n = 12). Four patients failed to complete 6 cycles (2 progressive disease and 2 toxicity). Grade ≥3 toxicity was experienced in 8% of cycles (13 of 165). The estimated median relapse-free survival (RFS) was 45.2 months. RFS at 18 months was estimated to be 59% (95% confidence interval [CI], 43–80), 2-year overall survival (OS) was 85% (95% CI, 72–99.8), and the median follow-up was 27.9 months. Six patients (21%) have died; median OS has not been reached. In univariate analyses, p27 and MSI status were not predictive for RFS while p53 approached statistical significance (P = 0.051). Duration of chemotherapy was the only significant predictive factor (P = 0.006). Conclusion:The tolerability of this regimen after major liver resection supports further evaluation of irinotecan-based adjuvant chemotherapy in this group of patients.

NCCN Guidelines® Insights Colon Cancer, Version 2.2018 Featured Updates to the NCCN Guidelines

The NCCN Guidelines for Colon Cancer provide recommendations regarding diagnosis, pathologic staging, surgical management, perioperative treatment, surveillance, management of recurrent and metastatic disease, and survivorship. These NCCN Guidelines Insights summarize the NCCN Colon Cancer Panel discussions for the 2018 update of the guidelines regarding risk stratification and adjuvant treatment for patients with stage III colon cancer, and treatment of BRAF V600E mutation-positive metastatic colorectal cancer with regimens containing vemurafenib.