Ramucirumab for Patients with Intermediate-Stage Hepatocellular Carcinoma and Elevated Alpha-Fetoprotein: Pooled Results from Two Phase 3 Studies (REACH and REACH-2).

BACKGROUND: Intermediate-stage hepatocellular carcinoma (HCC), as defined by Barcelona Clinic Liver Cancer (BCLC) stage B, is heterogeneous in terms of liver function and tumor burden. REACH and REACH-2 investigated ramucirumab in patients with HCC after prior sorafenib, with REACH-2 enrolling only patients with baseline α-fetoprotein (AFP) ≥400 ng/mL. An exploratory analysis of outcomes by BCLC stage was performed. METHODS: A pooled meta-analysis of independent patient data (stratified by study) from REACH (AFP ≥ 400 ng/mL) and REACH-2 was performed. All patients had Child-Pugh A, Eastern Cooperative Oncology Group performance status 0-1, prior sorafenib treatment, and either HCC BCLC stage B (refractory/not amenable to locoregional therapy) or BCLC stage C. Patients were randomized to ramucirumab 8 mg/kg or placebo every 2 weeks. Median overall survival (OS) and progression-free survival were estimated by the Kaplan-Meier method. Treatment effects in BCLC stage B and C were evaluated by Cox proportional-hazards model; prognosis of BCLC staging for OS was evaluated by multivariate Cox proportional-hazards model. Tumor responses were evaluated according to Response Evaluation in Solid Tumors v1.1. Liver function was assessed with albumin-bilirubin score. RESULTS: Baseline characteristics were generally balanced between treatment arms in each BCLC stage. BCLC staging trended as an independent prognostic factor for OS (B vs. C; hazard ratio [HR] 0.756 [95% CI 0.546-1.046]). Consistent treatment benefit was observed for ramucirumab versus placebo across BCLC stages. Median OS for ramucirumab versus placebo was 13.7 versus 8.2 months; HR (95%): 0.43 (0.23-0.83) and 7.7 versus 4.8 months; HR (95%): 0.72 (0.59-0.89) for BCLC stage B and C, respectively. Adverse events (AEs) were consistent with observations from both studies; hypertension was the most frequent grade ≥3 AE. Liver function was preserved throughout the study and similar between treatment arms in both BCLC stages. CONCLUSIONS: Ramucirumab provided a better survival benefit irrespective of BCLC stage and was well tolerated without compromising liver function during treatment.

Antitumor Activity and Mechanistic Characterization of APE1/Ref-1 Inhibitors in Bladder Cancer.

Bladder cancer is the ninth most common cause of cancer-related deaths worldwide. Although cisplatin is used routinely in treating bladder cancer, refractory disease remains lethal for many patients. The recent addition of immunotherapy has improved patient outcomes; however, a large cohort of patients does not respond to these treatments. Therefore, identification of innovative molecular targets for bladder cancer is crucial. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in both DNA repair and activation of transcription factors through reduction-oxidation (redox) regulation. High APE1/Ref-1 expression is associated with shorter patient survival time in many cancer types. In this study, we found high APE1/Ref-1 expression in human bladder cancer tissue relative to benign urothelium. Inhibition of APE1/Ref-1 redox signaling using APE1/Ref-1-specific inhibitors attenuates bladder cancer cell proliferation in monolayer, in three-dimensional cultures, and in vivo. This inhibition corresponds with an increase in apoptosis and decreased transcriptional activity of NF-κB and STAT3, transcription factors known to be regulated by APE1/Ref-1, resulting in decreased expression of downstream effectors survivin and Cyclin D1 in vitro and in vivo. We also demonstrate that in vitro treatment of bladder cancer cells with APE1/Ref-1 redox inhibitors in combination with standard-of-care chemotherapy cisplatin is more effective than cisplatin alone at inhibiting cell proliferation. Collectively, our data demonstrate that APE1/Ref-1 is a viable drug target for the treatment of bladder cancer, provide a mechanism of APE1/Ref-1 action in bladder cancer cells, and support the use of novel redox-selective APE1/Ref-1 inhibitors in clinical studies. SIGNIFICANCE: This work identifies a critical mechanism for APE1/Ref-1 in bladder cancer growth and provides compelling preclinical data using selective redox activity inhibitors of APE1/Ref-1 in vitro and in vivo.

APE1/Ref-1 redox-specific inhibition decreases survivin protein levels and induces cell cycle arrest in prostate cancer cells.

A key feature of prostate cancer progression is the induction and activation of survival proteins, including the Inhibitor of Apoptosis (IAP) family member survivin. Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein that is essential in activating oncogenic transcription factors. Because APE1/Ref-1 is expressed and elevated in prostate cancer, we sought to characterize APE1/Ref-1 expression and activity in human prostate cancer cell lines and determine the effect of selective reduction-oxidation (redox) function inhibition on prostate cancer cells in vitro and in vivo. Due to the role of oncogenic transcriptional activators NFĸB and STAT3 in survivin protein expression, and APE1/Ref-1 redox activity regulating their transcriptional activity, we assessed selective inhibition of APE1/Ref-1's redox function as a novel method to halt prostate cancer cell growth and survival. Our study demonstrates that survivin and APE1/Ref-1 are significantly higher in human prostate cancer specimens compared to noncancerous controls and that APE1/Ref-1 redox-specific inhibition with small molecule inhibitor, APX3330 and a second-generation inhibitor, APX2009, decreases prostate cancer cell proliferation and induces cell cycle arrest. Inhibition of APE1/Ref-1 redox function significantly reduced NFĸB transcriptional activity, survivin mRNA and survivin protein levels. These data indicate that APE1/Ref-1 is a key regulator of survivin and a potentially viable target in prostate cancer.

Coordinated induction of cell survival signaling in the inflamed microenvironment of the prostate.

PURPOSE: Both prostate cancer and benign prostatic hyperplasia are associated with inflammatory microenvironments. Inflammation is damaging to tissues, but it is unclear how the inflammatory microenvironment protects specialized epithelial cells that function to proliferate and repair the tissue. The objective of this study is to characterize the cell death and cell survival response of the prostatic epithelium in response to inflammation. METHODS: We assessed induction of cell death (TNF, TRAIL, TWEAK, FasL) and cell survival factors (IGFs, hedgehogs, IL-6, FGFs, and TGFs) in inflamed and control mouse prostates by ELISA. Cell death mechanisms were determined by immunoblotting and immunofluorescence for cleavage of caspases and TUNEL. Survival pathway activation was assessed by immunoblotting and immunofluorescence for Mcl-1, Bcl-2, Bcl-XL, and survivin. Autophagy was determined by immunoblotting and immunofluorescence for free and membrane associated light chain 3 (LC-3). RESULTS: Cleavage of all four caspases was significantly increased during the first 2 days of inflammation, and survival protein expression was substantially increased subsequently, maximizing at 3 days. By 5 days of inflammation, 50% of prostatic epithelial cells expressed survivin. Autophagy was also evident during the recovery phase (3 days). Finally, immunofluorescent staining of human specimens indicates strong activation of survival proteins juxtaposed to inflammation in inflamed prostate specimens. CONCLUSIONS: The prostate responds to deleterious inflammation with induction of cell survival mechanisms, most notably survivin and autophagy, demonstrating a coordinated induction of survival factors that protects and expands a specialized set of prostatic epithelial cells as part of the repair and recovery process during inflammation.