Evaluation of the dual mTOR / PI3K inhibitors Gedatolisib (PF-05212384) and PF-04691502 against ovarian cancer xenograft models

We are grateful to Wyeth/Pfizer (ONC-EU-150) and to the Scottish Funding Council (SRDG HR07005) for support of this study.This study investigated the antitumour effects of two dual mTOR/PI3K inhibitors, gedatolisib (WYE-129587/PKI-587/PF-05212384) and PF-04691502 against a panel of six human patient derived ovarian cancer xenograft models. Both dual mTOR/PI3K inhibitors demonstrated antitumour activity against all xenografts tested. The compounds produced tumour stasis during the treatment period and upon cessation of treatment, tumours re-grew. In several models, there was an initial rapid reduction of tumour volume over the first week of treatment before tumour stasis. No toxicity was observed during treatment. Biomarker studies were conducted in two xenograft models; phospho-S6 (Ser235/236) expression (as a readout of mTOR activity) was reduced over the treatment period in the responding xenograft but expression increased to control (no treatment) levels on cessation of treatment. Phospho-AKT (Ser473) expression (as a readout of PI3K) was inhibited by both drugs but less markedly so than phospho-S6 expression. Initial tumour volume reduction on treatment and regrowth rate after treatment cessation was associated with phospho-S6/total S6 expression ratio. Both drugs produced apoptosis but minimally influenced markers of proliferation (Ki67, phospho-histone H3). These results indicate that mTOR/PI3K inhibition can produce broad spectrum tumour growth stasis in ovarian cancer xenograft models during continuous chronic treatment and this is associated with apoptosis.Publisher PDFPeer reviewe

Deep sequencing of gastric carcinoma reveals somatic mutations relevant to personalized medicine

<p>Abstract</p> <p>Background</p> <p>Globally, gastric cancer is the second most common cause of cancer-related death, with the majority of the health burden borne by economically less-developed countries.</p> <p>Methods</p> <p>Here, we report a genetic characterization of 50 gastric adenocarcinoma samples, using affymetrix SNP arrays and Illumina mRNA expression arrays as well as Illumina sequencing of the coding regions of 384 genes belonging to various pathways known to be altered in other cancers.</p> <p>Results</p> <p>Genetic alterations were observed in the WNT, Hedgehog, cell cycle, DNA damage and epithelial-to-mesenchymal-transition pathways.</p> <p>Conclusions</p> <p>The data suggests targeted therapies approved or in clinical development for gastric carcinoma would be of benefit to ~22% of the patients studied. In addition, the novel mutations detected here, are likely to influence clinical response and suggest new targets for drug discovery.</p

Phase III Study to Evaluate Efficacy and Safety of Andecaliximab With mFOLFOX6 as First-Line Treatment in Patients With Advanced Gastric or GEJ Adenocarcinoma (GAMMA-1).

Purpose Andecaliximab (ADX) is a monoclonal antibody that inhibits matrix metalloproteinase 9, an extracellular enzyme involved in matrix remodeling, tumor growth, and metastases. A phase I and Ib study of modified oxaliplatin, leucovorin, and fluorouracil (mFOLFOX6) with ADX revealed encouraging antitumor activity in patients with gastric or gastroesophageal junction (GEJ) adenocarcinoma.Materials and methods This phase III, randomized, double-blinded, placebo (PBO)-controlled multicenter study investigated the efficacy and safety of mFOLFOX6 with and without ADX in patients with untreated human epidermal growth factor receptor 2-negative gastric or GEJ adenocarcinoma. Random assignment was 1:1 to mFOLFOX6 + ADX or mFOLFOX6 + PBO. ADX/PBO 800 mg was infused on days 1 and 15 of each 28-day cycle. Protocol therapy was given until disease progression or intolerance. The primary end point was overall survival (OS), and secondary end points were progression-free survival (PFS), objective response rate (RECIST 1.1), and safety.Results Between September 2015 and May 2017, 432 patients were randomly assigned, 218 to ADX and 214 to PBO. The median OS was 12.5 versus 11.8 months in the ADX and PBO groups, respectively. The median PFS was 7.5 versus 7.1 months in the ADX and PBO groups, respectively. The objective response rate was 51% in the ADX group and 41% in the PBO group. Among the subgroup analyses, patients of age ≥ 65 years had an improved OS and PFS with ADX versus PBO; the P values and CIs were not adjusted for multiplicity. There were no meaningful differences in the safety profile of the ADX versus PBO groups.Conclusion The addition of ADX to mFOLFOX6 did not improve OS in unselected patients with untreated human epidermal growth factor receptor 2-negative gastric or GEJ adenocarcinoma