Research protocol to identify progression and death amongst patients with metastatic hormone-sensitive prostate cancer treated with available treatments: PIONEER IMI's "big data for better outcomes" program

Androgen deprivation therapy-based with or without first-generation anti-androgens, was the standard of care for patients with metastatic hormone-sensitive prostate cancer (mHSPC) for decades. However, the development of docetaxel chemotherapy and new androgen receptor-targeted agents, abiraterone acetate and prednisolone, apalutamide , enzalutamide and darolutamide (in combination with docetaxel chemotherapy) has proven that combination of treatments is more effective. Recently, intensification therapy, so-called "triplets", have emerged in the armamentarium of mHSPC treatment. Metastatic disease is a clinical state that remains poorly understood. The optimal diagnostic and management of patients with mHSPC are changing thanks to the development of new imaging techniques and therapies. The primary objective of this study is to develop and validate a predictive model for the occurrence of symptomatic progression, initiation of new treatments and death amongst patients with mHSPC treated with one of the approved treatment plans, on characteristics present at admission.

Unanswered questions in prostate cancer - findings of an international multi-stakeholder consensus by the PIONEER consortium

PIONEER is a European network of excellence for big data in prostate cancer consisting of 37 private and public stakeholders from 9 countries across Europe. Many progresses have been done in prostate cancer management, but unanswered questions in the field still exist, and big data could help to answer these questions. The PIONEER consortium conducted a two-round modified Delphi survey aiming at building consensus between two stakeholder groups - health-care professionals and patients with prostate cancer - about the most important questions in the field of prostate cancer to be answered using big data. Respondents were asked to consider what would be the effect of answering the proposed questions on improving diagnosis and treatment outcomes for patients with prostate cancer and to score these questions on a scale of 1 (not important) to 9 (critically important). The mean percentage of participants who scored each of the proposed questions as critically important was calculated across the two stakeholder groups and used to rank the questions and identify the highest scoring questions in the critically important category. The identification of questions in prostate cancer that are important to various stakeholders will help the PIONEER consortium to provide answers to these questions to improve the clinical care of patients with prostate cancer.

Abstract C179: Preclinical characterization of GPA512: A prodrug of a direct STAT3 inhibitor for the treatment of prostate cancer

Background: The transcription factor STAT3 is a promising target for the treatment of castration-resistant prostate cancer (CRPC) as STAT3 is implicated in drug resistance and castration resistance as well as metastatic spread, tumor growth and immune escape. Galiellalactone (GL) is a direct inhibitor of STAT3 that prevents DNA binding, inhibits proliferation of prostate cancer cells expressing active STAT3 and induces apoptosis by down-regulation of STAT3 activated genes. In this study we aimed to characterize a prodrug of GL, GPA512, with improved drug-like properties and to demonstrate its effect on tumor growth in a xenograft model of prostate cancer following oral administration.

Methods: Stability studies of prodrugs based on GL were performed in 0.1 M PBS buffer (pH 7.4) and in plasma at 37°C. In vitro efficacy of prodrugs was studied by WST-1 proliferation assay in DU145 prostate cancer cells expressing active STAT3. The systemic exposure of GL in mice was studied following a single oral dose of GPA512 or GL (both 10 mg/kg). The plasma concentrations of GL were determined by LC-MS/MS. For the xenograft study NMRI-nude male mice were inoculated subcutaneously with DU145 cells and once tumors were established the mice were divided in two groups with ten mice in each. Mice were treated orally with 40 mg/kg GPA512 daily five times/week for four weeks. Tumor growth was measured by caliper and at the end of the study tumors were harvested for subsequent analyses using immunohistochemistry and mRNA expression analysis.

Results: In vitro studies showed that the prodrug GPA512 is rapidly converted to GL in plasma and that GPA512 is stable in buffer solution and has similar inhibitory effects on proliferation as GL on DU145 cells. The pharmacokinetics of GPA512 following a single oral dose indicated that the compound was rapidly absorbed and converted to GL with a tmax of 15 min. Oral administration of GPA512 in mice increased the plasma exposure (AUC) of the active parent compound 20-fold compared to when GL was dosed orally. GPA512 treated mice bearing subcutaneous DU145 tumors had significantly smaller tumors compared to mice treated with vehicle. No adverse effects or weight loss were observed. Analysis of tumors showed decreased cell proliferation and increased amount of apoptotic cells in GPA512 treated mice compared to control. The mRNA expression of STAT3 regulated anti-apoptotic gene MCl-1 was significantly reduced by GPA512 treatment.

Conclusions: The drug-like properties and safety profile of the prodrug GPA512 and galiellalactone's direct inhibition of STAT3, warrant further studies of GPA512 as a drug candidate for treatment of patients with CRPC.

Citation Format: Rebecka Hellsten, Zilma Escobar, Anders Bjartell, Giacomo Canesin, Susan Evans Axelsson, Olov Sterner, Martin Johansson. Preclinical characterization of GPA512: A prodrug of a direct STAT3 inhibitor for the treatment of prostate cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C179.

Surgical treatment of temporomandibular joint luxation

Eminectomy with or without diskectomy was performed in 19 patients with temporomandibular joint luxation. Three of them were long-standing luxations (duration between three months and one year). The remaining 16 patients had recurrent luxations. The follow-up period was three years. No complications such as infection or permanent palsy of the facial nerve occurred. However, transient palsy of the temporal branch of the facial nerve, which resolved within three months was seen in 4 patients (21%). After treatment two patients had recurrent luxations. In the remaining 17 patients, two developed painful clicking of one TMJ, requiring additional surgery (one patient had arthroscopic lysis and lavage and the other one diskectomy). If these two are also regarded as unsuccessful cases, the overall long-term success rate was 79%. A comparison of the subgroups who underwent eminectomy alone and eminectomy with diskectomy showed that all unsuccessful cases occurred in the former group.