Bethany J. Horton

Performance of toxicity probability interval based designs in contrast to the continual reassessment method

Toxicity probability interval designs have received increasing attention as a dose-finding method in recent years. In this study, we compared the two-stage, likelihood-based continual reassessment method (CRM), modified toxicity probability interval (mTPI), and the Bayesian optimal interval design (BOIN) in order to evaluate each methods performance in dose selection for phase I trials. We use several summary measures to compare the performance of these methods, including percentage of correct selection (PCS) of the true maximum tolerable dose (MTD), allocation of patients to doses at and around the true MTD, and an accuracy index. This index is an efficiency measure that describes the entire distribution of MTD selection and patient allocation by taking into account the distance between the true probability of toxicity at each dose level and the target toxicity rate. The simulation study considered a broad range of toxicity curves and various sample sizes. When considering PCS, we found that CRM outperformed the two competing methods in most scenarios, followed by BOIN, then mTPI. We observed a similar trend when considering the accuracy index for dose allocation, where CRM most often outperformed both mTPI and BOIN. These trends were more pronounced with increasing number of dose levels. Copyright

A Phase II study of Dovitinib in Patients With Recurrent or Metastatic Adenoid Cystic Carcinoma

Purpose: Genetic and preclinical studies have implicated FGFR signaling in the pathogenesis of adenoid cystic carcinoma (ACC). Dovitinib, a suppressor of FGFR activity, may be active in ACC. Experimental Design: In a two-stage phase II study, 35 patients with progressive ACC were treated with dovitinib 500 mg orally for 5 of 7 days continuously. The primary endpoints were objective response rate and change in tumor growth rate. Progression-free survival, overall survival, metabolic response, biomarker, and quality of life were secondary endpoints. Results: Of 34 evaluable patients, 2 (6%) had a partial response and 22 (65%) had stable disease >4 months. Median PFS was 8.2 months and OS was 20.6 months. The slope of the overall TGR fell from 1.95 to 0.63 on treatment (P < 0.001). Toxicity was moderate; 63% of patients developed grade 3–4 toxicity, 94% required dose modifications, and 21% stopped treatment early. An early metabolic response based on 18FDG-PET scans was seen in 3 of 15 patients but did not correlate with RECIST response. MYB gene translocation was observed and significantly correlated with overexpression of MYB but did not correlate with FGFR1 phosphorylation or clinical response to dovitinib. Conclusions: Dovitinib produced few objective responses in patients with ACC but did suppress the TGR with a PFS that compares favorably with those reported with other targeted agents. Future studies of more potent and selective FGFR inhibitors in biomarker-selected patients will be required to determine whether FGFR signaling is a valid therapeutic target in ACC. Clin Cancer Res; 23(15); 4138–45. ©2017 AACR.

Quantitative Analysis of the Cellular Microenvironment of Glioblastoma to Develop Predictive Statistical Models of Overall Survival

Glioblastomas, the most common primary malignant brain tumors, have a distinct tissue microenvironment. Although non-neoplastic cells contribute to glioblastoma progression, very few quantitative studies have shown the effect of tumor microenvironmental influences on patient survival. We examined relationships of the cellular microenvironment, including astrocytes, microglia, oligodendrocytes, and blood vessels, to survival in glioblastoma patients. Using histological staining and quantitative image analyses, we examined the tumor-associated parenchyma of 33 patients and developed statistical models to predict patient outcomes based on the cellular picture of the tumor parenchyma. We found that blood vessel density correlated with poorer prognosis. To examine the role of adjacent parenchymal versus higher tumor cell density bulk parenchymal tissue, we examined the glial components in these highly variable regions. Comparison of bulk and adjacent astrocytes and microglia in tissue yielded the strongest prediction of survival, with high levels of adjacent astrocytes predicted poor prognosis and high levels of microglia correlated with a better prognosis. These results indicate that parenchymal components predict survival in glioblastoma patients and in particular that the balance between reactive glial populations is important for patient prognosis.

Risk of Major Bleeding with Ibrutinib

&NA; Ibrutinib is a highly effective therapy for non‐Hodgkin lymphoma and chronic lymphocytic leukemia. However, ibrutinib has also been associated with an increased risk of bleeding, although major bleeding has been infrequent in clinical trials. In the present retrospective analysis, major bleeding occurred in 19% of patients receiving ibrutinib and was associated with baseline anemia, an elevated international normalized ratio, and concurrent antiplatelet and anticoagulant use. A risk versus benefit analysis of these factors is essential for treatment with ibrutinib. Background: The Bruton tyrosine kinase inhibitor, ibrutinib, is an effective therapy against mature B‐cell malignancies. Although generally well tolerated, serious bleeding emerged during developmental clinical trials as an unexpected, although uncommon, adverse event. As the use of ibrutinib increases outside of the clinical trial setting and in patients with more comorbidities, the rate of major bleeding could be greater. Materials and Methods: A retrospective analysis the data from all patients at our center and its regional clinics who had been prescribed ibrutinib from January 2012 to May 2016 were reviewed for demographic data, comorbid illnesses, bleeding events, and concurrent medications. Results: We identified 70 patients. Bleeding of any grade occurred in 56% of patients, mostly grade 1 to 2 bruising and epistaxis. Major bleeding, defined as grade ≥ 3, occurred in 19% of patients, greater than previously reported. Anemia (hemoglobin < 12 g/dL; hazard ratio [HR], 5.0; 95% confidence interval [CI], 1.4‐18.2; P = .02) and an elevated international normalized ratio (> 1.5; HR, 9.5; 95% CI, 2.7‐33.5; P < .01) at ibrutinib initiation were associated with an increased risk of major bleeding. Of those with major bleeding, most patients were also taking an antiplatelet agent (70%), an anticoagulant (17%), or a CYP 3A4 inhibitor (7%), with 13% taking both antiplatelet and anticoagulant medications. The use of both antiplatelet and anticoagulant therapy significantly increased the risk of a major bleed event (HR, 19.2; 95% CI, 2.3‐166.7; P < .01). Conclusion: The results of the present study have demonstrated a greater rate of major bleeding with ibrutinib use in a standard clinical setting than previously reported. Patients with anemia or an elevated international normalized ratio or requiring anticoagulant and/or antiplatelet medications during ibrutinib therapy have a significantly increased risk of major bleeding. Careful consideration of the risks and benefits for this population is needed. The combination of antiplatelet and anticoagulation medications with ibrutinib therapy is of particular concern.

Diagnostic Efficiency in Digital Pathology: A Comparison of Optical Versus Digital Assessment in 510 Surgical Pathology Cases.

Prior work has shown that digital images and microscopic slides can be interpreted with comparable diagnostic accuracy. Although accuracy has been well-validated, the interpretative time for digital images has scarcely been studied and concerns about efficiency remain a major barrier to adoption. We investigated the efficiency of digital pathology when compared with glass slide interpretation in the diagnosis of surgical pathology biopsy and resection specimens. Slides were pulled from 510 surgical pathology cases from 5 organ systems (gastrointestinal, gynecologic, liver, bladder, and brain). Original diagnoses were independently confirmed by 2 validating pathologists. Diagnostic slides were scanned using the Philips IntelliSite Pathology Solution. Each case was assessed independently on digital and optical by 3 reading pathologists, with a ≥6 week washout period between modalities. Reading pathologists recorded assessment times for each modality; digital times included time to load the case. Diagnostic accuracy was determined based on whether a rendered diagnosis differed significantly from the original diagnosis. Statistical analysis was performed to assess for differences in interpretative times across modalities. All 3 reading pathologists showed comparable diagnostic accuracy across optical and digital modalities (mean major discordance rates with original diagnosis: 4.8% vs. 4.4%, respectively). Mean assessment times ranged from 1.2 to 9.1 seconds slower on digital versus optical. The slowest reader showed a significant learning effect during the course of the study so that digital assessment times decreased over time and were comparable with optical times by the end of the series. Organ site and specimen type did not significantly influence differences in interpretative times. In summary, digital image reading times compare favorably relative to glass slides across a variety of organ systems and specimen types. Mean increase in assessment time is 4 seconds/case. This time can be minimized with experience and may be further balanced by the improved ease of electronic chart access allowed by digital slide viewing, as well as quantitative assessments which can be expedited on digital images.