A Phase I Study Investigating AZD8186, a Potent and Selective Inhibitor of PI3Kß/δ, in Patients with Advanced Solid Tumors.

PURPOSE: To characterize safety and tolerability of the selective PI3Kß inhibitor AZD8186, identify a recommended phase II dose (RP2D), and assess preliminary efficacy in combination with abiraterone acetate or vistusertib. PATIENTS AND METHODS: This phase I open-label study included patients with advanced solid tumors, particularly prostate cancer, triple-negative breast cancer, and squamous non-small cell lung cancer. The study comprised four arms: (i) AZD8186 monotherapy dose finding; (ii) monotherapy dose expansion; (iii) AZD8186/abiraterone acetate (with prednisone); and (iv) AZD8186/vistusertib. The primary endpoints were safety, tolerability, and identification of the RP2D of AZD8186 monotherapy and in combination. Secondary endpoints included pharmacokinetics (PK), pharmacodynamics, and tumor and prostate-specific antigen (PSA) responses. RESULTS: In total, 161 patients were enrolled. AZD8186 was well tolerated across all study arms, the most common adverse events being gastrointestinal symptoms. In the monotherapy dose-finding arm, four patients experienced dose-limiting toxicities (mainly rash). AZD8186 doses of 60-mg twice daily [BID; 5 days on, 2 days off (5:2)] and 120-mg BID (continuous and 5:2 dosing) were taken into subsequent arms. The PKs of AZD8186 were dose proportional, without interactions with abiraterone acetate or vistusertib, and target inhibition was observed in plasma and tumor tissue. Monotherapy and combination therapy showed preliminary evidence of limited antitumor activity by imaging and, in prostate cancer, PSA reduction. CONCLUSIONS: AZD8186 monotherapy had an acceptable safety and tolerability profile, and combination with abiraterone acetate/prednisone or vistusertib was also tolerated. There was preliminary evidence of antitumor activity, meriting further exploration of AZD8186 in subsequent studies in PI3Kß pathway-dependent cancers.

GRP receptor imaging of prostate cancer using [(99m)Tc]Demobesin 4: a first-in-man study.

PURPOSE: We explored the imaging of bombesin receptors and evaluated the clinical use of [(99m)Tc]Demobesin 4 ([(99m)Tc]DB4) in prostate cancer patients. PROCEDURES: [(99m)Tc]DB4 was prepared according to Good Manufacturing Practice. Patients with prostate cancer underwent serial planar and SPECT imaging up to 3 h after administration. Blood and urine samples were taken to assess pharmacokinetics. RESULTS: [(99m)Tc]DB4 is safe and clears rapidly from the bloodstream via the kidneys resulting in low background activity. The tracer binds strongly to the gastrin-releasing peptide receptor (GRPR) in vivo as indicated by the high uptake in the pancreas seen in all patients. In patients who had undergone hormone therapy, [(99m)Tc]DB4 did not efficiently image metastatic prostate cancer. In contrast, in newly diagnosed patients local disease was visualised. CONCLUSIONS: The GRPR is an unsuitable target for imaging refractory prostate cancer but may be useful in untreated disease. [(99m)Tc]DB4 is a promising radiopharmaceutical which merits further exploration in this specific group of patients.

High throughput production of recombinant human proteins for crystallography.

This chapter presents in detail the process used in high throughput bacterial production of recombinant human proteins for crystal structure determination. The core principles are: (1) Generating at least 10 truncated constructs from each target gene. (2) Ligation-independent cloning (LIC) into a bacterial expression vector. All proteins are expressed with an N-terminal, TEV protease cleavable fusion peptide. (3) Small-scale test expression to identify constructs producing soluble protein. (4) Liter-scale production in shaker flasks. (5) Purification by Ni-affinity chromatography and gel filtration. (6) Protein characterization and preparation for crystallography. The chapter also briefly presents alternative procedures, to be applied based on specific knowledge of protein families or when the core protocol is unsatisfactory. This scheme has been applied to more than 550 human proteins (>10,000 constructs) and has resulted in the deposition of 112 unique structures. The methods presented do not depend on specialized equipment or robotics; hence, they provide an effective approach for handling individual proteins in a regular research lab.