Targeting of the Hedgehog/GLI and mTOR pathways in advanced pancreatic cancer, a phase 1 trial of Vismodegib and Sirolimus combination.

BACKGROUND/OBJECTIVES: Preclinical data indicated a functional and molecular interaction between Hedgehog (HH)/GLI and PI3K-AKT-mTOR pathways promoting pancreatic ductal adenocarcinoma (PDAC). A phase I study was conducted of Vismodegib and Sirolimus combination to evaluate maximum tolerated dose (MTD) and preliminary anti-tumor efficacy. METHODS: Cohort I included advanced solid tumors patients following a traditional 3 + 3 design. Vismodegib was orally administered at 150 mg daily with Sirolimus starting at 3 mg daily, increasing to 6 mg daily at dose level 2. Cohort II included only metastatic PDAC patients. Anti-tumor efficacy was evaluated every two cycles and target assessment at pre-treatment and after a single cycle. RESULTS: Nine patient were enrolled in cohort I and 22 patients in cohort II. Twenty-eight patients were evaluated for dose-limiting toxicities (DLTs). One DLT was observed in each cohort, consisting of grade 2 mucositis and grade 3 thrombocytopenia. The MTD for Vismodegib and Sirolimus were 150 mg daily and 6 mg daily, respectively. The most common grade 3-4 toxicities were fatigue, thrombocytopenia, dehydration, and infections. A total of 6 patients had stable disease. No partial or complete responses were observed. Paired biopsy analysis before and after the first cycle in cohort II consistently demonstrated reduced GLI1 expression. Conversely, GLI and mTOR downstream targets were not significantly affected. CONCLUSIONS: The combination of Vismodegib and Sirolimus was well tolerated. Clinical benefit was limited to stable disease in a subgroup of patients. Targeting efficacy demonstrated consistent partial decreases in HH/GLI signaling with limited impact on mTOR signaling. These findings conflict with pre-clinical models and warrant further investigations.

A phase I study of the vascular endothelial growth factor inhibitor Vatalanib in combination with Pemetrexed disodium in patients with advanced solid tumors.

Introduction Vatalanib is an oral receptor tyrosine kinase inhibitor that blocks all known VEGF, PDGF, and c-Kit receptors. This phase I study evaluated the safety, tolerability, and biologic activity of the combination of vatalanib with pemetrexed disodium in patients with advanced solid tumors. Methods Patients were administered escalating twice daily doses of vatalanib in combination with pemetrexed disodium in 21-day cycles. A dose expansion cohort was enrolled to further define the maximum tolerated dose (MTD) and further evaluate efficacy. Results A total of 29 patients were enrolled in the study (dose escalation, 9; dose expansion, 20). Dose-limiting toxicities included grade 4 thrombocytopenia (6.9%) and febrile neutropenia, anorexia, constipation, and dehydration. Other common adverse events were fatigue (75%), nausea (66%), vomiting (48%), oral mucositis (31%) and diarrhea (28%). The majority of these toxicities were Grade 1-2. The MTD was reached at vatalanib 250 mg twice daily continuously combined with pemetrexed disodium 500 mg/m2 day 1. Overall, 2 patients (6.9%) had partial responses, 8 (27.6%) had stable disease for at least 4 cycles, 5 had progressive disease (17.2%) and 5 went off study before disease assessment. Conclusion The combination of vatalanib with pemetrexed disodium was feasible, but not well tolerated. The modest efficacy results are consistent with other results obtained from combinations of chemotherapy and a large number of VEGF tyrosine kinase inhibitors. This combination should not be developed further unless predictive biomarkers can be identified.

A phase I study of the farnesyltransferase inhibitor Tipifarnib in combination with the epidermal growth factor tyrosine kinase inhibitor Erlotinib in patients with advanced solid tumors.

Introduction Based on preclinical cytotoxic synergy between tipifarnib and erlotinib, a phase I study of this combination was conducted in patients with advanced solid tumors to evaluate safety, tolerability, maximum tolerated dose (MTD) and preliminary evidence of efficacy. Methods Patient enrollment followed the traditional "3 + 3" dose escalation scheme, through 4 dose levels, ranging from tipifarnib 200 mg twice daily plus erlotinib 75 mg once daily to tipifarnib 300 mg twice daily plus erlotinib 150 mg once daily. After the MTD of the combination was identified, 12 additional patients were treated to better define the pharmacokinetics and pharmacodynamics of these agents. Results A total of 27 patients were enrolled in the study (dose escalation, 15; dose expansion, 12). Dose limiting toxicity was seen in one patient at dose level 4 (grade 3 diarrhea). The MTD was reached at erlotinib 150 mg once daily combined with tipifarnib 300 mg twice daily. The most common side effects of the combination of all grades were diarrhea (85.2%), fatigue (77.8%), rash (70.4%), and anorexia (59.3%). Overall, 2 patients (7.4%; with liver cancer and melanoma, respectively) had partial responses, 10 (37%) had stable disease, 11 had progressive disease (40.7%) and 4 stopped treatment prematurely for assessment. Conclusion The combination of tipifarnib and erlotinib was well tolerated. Erlotinib 150 mg once daily for 28 days combined with tipifarnib 300 mg twice daily for 21 days was identified as the recommended phase 2 dose. Tipifarnib is currently being evaluated in HRAS mutant tumors, providing a potential opportunity to further test this combination.

New Pulmonary Infiltrates Observed on Computed Tomography-Based Image Guidance for Radiotherapy Warrant Diagnostic Workup for Coronavirus Disease 2019.

INTRODUCTION: Screening for coronavirus disease 2019 (COVID-19) exposure, coupled with engaged decision making to prioritize cancer treatment in parallel with reducing risk of exposure and infection, is crucial in the management of COVID-19 during cancer treatment. After two reported case studies of imaging findings during daily computed tomography (CT)-based image-guided radiotherapy (RT) scans, a call for submission of anonymized case reports was published with the objective of rapidly determining if there was a correlation between the onset of new pulmonary infiltrates found during RT and COVID-19. We hereby report the results of the aggregate analysis. METHODS: Data of deidentified case reports for patients who developed biochemically confirmed COVID-19 during RT were submitted through an online portal. Information requested included a patient's sex, age, cancer diagnosis and treatment, and COVID-19 diagnosis and outcome. Coplanar CT-based imaging was requested to reveal the presence or absence of ground-glass opacities or infiltrates. RESULTS: A total of seven reports were submitted from Turkey, Spain, Belgium, Egypt, and the United States. Results and imaging from the patients reported by Suppli et al. and McGinnis et al. were included for a total of nine patients for analysis. All patients were confirmed COVID-19 positive using polymerase chain reaction-based methods or nasopharyngeal swabs. Of the nine patients analyzed, abnormalities consistent with ground-glass opacities or infiltrates were observed in eight patients. CONCLUSIONS: This is the largest case series revealing the potential use of CT-based image guidance during RT as a tool for identifying patients who need further workup for COVID-19. Considerations for reviewing image guidance for new pulmonary infiltrates and immediate COVID-19 testing in patients who develop new infiltrates even without COVID-19 symptoms are strongly encouraged.