Real-world treatment patterns and clinical outcomes with first-line therapy in patients with locally advanced/metastatic urothelial carcinoma by cisplatin-eligibility.

INTRODUCTION: Patients with locally advanced/metastatic urothelial carcinoma (la/mUC) have a poor prognosis. With recent therapeutic advances, data on real-world treatment patterns and overall survival (OS) in patients with la/mUC treated with first-line therapy are limited, particularly when comparing patients who are cisplatin-ineligible versus cisplatin-eligible. METHODS: This was a retrospective observational study of real-world first-line treatment patterns and OS in patients with la/mUC stratified by cisplatin-eligibility and treatment. Data were from a nationwide electronic health record-derived de-identified database. Eligible patients were adults diagnosed with la/mUC from May 2016 to April 2021 and followed until death or end of data availability in January 2022. OS stratified by first-line treatment and cisplatin eligibility was estimated using Kaplan-Meier methods and compared via multivariable Cox proportional-hazard models adjusted for clinical covariates. RESULTS: Of 4,757 patients with la/mUC, 3,632 (76.4%) received first-line treatment, with 2,029 (55.9%) cisplatin-ineligible and 1,603 (44.1%) cisplatin-eligible. Patients who were cisplatin-ineligible were older (mean age, 74.9 vs. 68.8 years) and had lower CrCl (median, 46.4 vs. 87.0 ml/min). Only 43.8% of patients receiving first-line treatment (37.6% cisplatin-ineligible vs. 51.6% cisplatin-eligible) received second-line therapy. Median OS in all patients receiving first-line treatment was 10.8 (95% CI, 10.2-11.3) months and was shorter in patients who were cisplatin-ineligible than cisplatin-eligible (8.5 [95% CI, 7.8-9.0] vs. 14.4 [13.3-16.1]; hazard ratio [HR], 0.9 [0.7-1.1]). Cisplatin-based therapy was associated with longer OS (17.6 [15.1-20.4] months) than other first-line treatments (the shortest OS was with PD-1/L1 inhibitor monotherapy; 7.7 [6.8-8.8] months), including among patients who were classified as cisplatin-ineligible. CONCLUSIONS: Outcomes for patients with newly diagnosed la/mUC are poor, particularly for patients who are cisplatin-ineligible and/or do not receive cisplatin-based therapy. Many patients with la/mUC did not receive first-line treatment and among those who did, fewer than half received second-line therapy. These data highlight the need for more effective first-line therapies for all patients with la/mUC.

Expression of IFN-beta enhances both efficacy and safety of oncolytic vesicular stomatitis virus for therapy of mesothelioma.

Our preclinical and clinical trials using a replication-defective adenoviral vector expressing IFN-beta have shown promising results for the treatment of malignant mesothelioma. Based on the hypotheses that a replication-competent vesicular stomatitis virus (VSV) oncolytic vector would transduce more tumor cells in vivo, that coexpression of the immunostimulatory IFN-beta gene would enhance the immune-based effector mechanisms associated both with regression of mesotheliomas and with VSV-mediated virotherapy, and that virus-derived IFN-beta would add further safety to the VSV platform, we tested the use of IFN-beta as a therapeutic transgene expressed from VSV as a novel treatment for mesothelioma. VSV-IFN-beta showed significant therapy against AB12 murine mesotheliomas in the context of both local and locoregional viral delivery. Biologically active IFN-beta expressed from VSV added significantly to therapy compared with VSV alone, dependent in part on host CD8+ T-cell responses. Immune monitoring suggested that these antitumor T-cell responses may be due to a generalized T-cell activation rather than the priming of tumor antigen-specific T-cell responses. Finally, IFN-beta also added considerable extra safety to the virus by providing protection from off-target viral replication in nontumor tissues and protected severe combined immunodeficient mice from developing lethal neurotoxicity. The enhanced therapeutic index provided by the addition of IFN-beta to VSV therefore provides a powerful justification for the development of this virus for future clinical trials.

Yeast cytosine deaminase mutants with increased thermostability impart sensitivity to 5-fluorocytosine.

Prodrug gene therapy (PGT) is a treatment strategy in which tumor cells are transfected with a 'suicide' gene that encodes a metabolic enzyme capable of converting a nontoxic prodrug into a potent cytotoxin. One of the most promising PGT enzymes is cytosine deaminase (CD), a microbial salvage enzyme that converts cytosine to uracil. CD also converts 5-fluorocytosine (5FC) to 5-fluorouracil, an inhibitor of DNA synthesis and RNA function. Over 150 studies of CD-mediated PGT applications have been reported since 2000, all using wild-type enzymes. However, various forms of CD are limited by inefficient turnover of 5FC and/or limited thermostability. In a previous study, we stabilized and extended the half-life of yeast CD (yCD) by repacking of its hydrophobic core at several positions distant from the active site. Here we report that random mutagenesis of residues selected based on alignment with similar enzymes, followed by selection for enhanced sensitization to 5FC, also produces an enzyme variant (yCD-D92E) with elevated T(m) values and increased activity half-life. The new mutation is located at the enzyme's dimer interface, indicating that independent mutational pathways can lead to an increase in stability, as well as a more subtle effect on enzyme kinetics. Each independently derived set of mutations significantly improves the enzyme's performance in PGT assays both in cell culture and in animal models.