Advances in ovarian cancer disease control

Ruxolitinib synergistically enhances the anti-tumor activity of paclitaxel in human ovarian cancer

Treatment for ovarian cancer remains challenging despite a high initial response rate to first line platinum-taxane treatment. Most patients eventually experience recurrence and require further treatment. Persistent activation of STAT3 is associated with cancer growth and progression and is also involved in cell resistance to platinum and taxane treatment. Targeting JAK/STAT3, therefore, could be a potential novel therapeutic approach for treating advanced and chemoresistant ovarian cancer. We investigated the therapeutic potential of ruxolitinib, a JAK1/JAK2 inhibitor that has been FDA-approved for the treatment of myelofibrosis, to treat ovarian cancer either alone or in combination with conventional chemotherapy agents. We show that ruxolitinib inhibits STAT3 activation and ovarian tumor growth both in ovarian cancer cells and in an ovarian cancer mouse model. In addition, ruxolitinib significantly increases the anti-tumor activity of chemotherapy agents, including paclitaxel, cisplatin, carboplatin, doxorubicin and topotecan in ovarian cancer cells. Evaluation of the combination index (CI) shows that ruxolitinib synergistically interacts with paclitaxel in all three human ovarian cancer cells. Finally, our results demonstrate that combination of ruxolitinib and paclitaxel leads to a greater reduction of tumor growth compared to single treatment of either agent in a tumor mouse model that represents late stage ovarian cancer with peritoneal metastasis and ascites formation. Taken together, our findings provide a foundation for clinical trials with ruxolitinib, either as a single agent or in combination with paclitaxel, for the treatment of recurrent and advanced ovarian cancer.

Adjuvant (post-surgery) chemotherapy for early stage epithelial ovarian cancer

BACKGROUND

This is the second update of the review first published in the Cochrane Database of Systematic Reviews in 2009, Issue 1. Epithelial ovarian cancer is diagnosed in over 200,000 women worldwide each year. Ten to 20% of women are diagnosed early, when there is still a good possibility of cure. The treatment of early-stage (stage I and IIa) disease involves surgery to remove the disease, often followed by chemotherapy (adjuvant chemotherapy). The largest clinical trials of adjuvant chemotherapy show an overall survival (OS) advantage with platinum-based chemotherapy; however the precise role and type of this treatment in subgroups of women with differing prognoses needs to be defined.

OBJECTIVES

To undertake a systematic review of the evidence for adjuvant chemotherapy in early-stage epithelial ovarian cancer to determine whether chemotherapy following surgery offers a survival advantage over the policy of observation following surgery (with chemotherapy reserved for treatment of disease recurrence); and to determine if clinical subgroups of women with differing prognoses, based on histological subtype or completeness of surgical staging, have more or less to gain from adjuvant chemotherapy.

SEARCH METHODS

We performed an electronic search using the Cochrane Gynaecological Cancer Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 3), MEDLINE (1948 to March week 5, 2015), and EMBASE (1980 to week 14, 2015). We developed the search strategy using free-text and medical subject headings (MeSH). We also searched registers of clinical trials and citation lists of included studies for potentially relevant studies.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) of women with early stage (I/IIa) epithelial ovarian cancer staged at laparotomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed study quality of included RCTs. We resolved any disagreements by discussion with a third review author. We used random-effects methods for all meta-analyses, including subgroup analyses.

MAIN RESULTS

The original version of this Cochrane review included five RCTs involving 1277 women. In this 2015 update, no new studies met the inclusion criteria but we included an additional paper with mature data (10-year follow-up) relating to a previously included study (ICON1).We included four studies in the meta-analyses and considered them to be at a low risk of bias. Most study participants (> 95%) had stage I ovarian cancer. Meta-analysis of five-year data from three studies indicated that women who received adjuvant platinum-based chemotherapy had better overall survival (OS) than those who did not (Hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.53 to 0.93; 1008 women; 3 studies; I² statistic = 0%; high quality evidence). Likewise, meta-analysis of five-year data from four studies indicated that women who received adjuvant chemotherapy had better progression-free survival (PFS) than those who did not (HR 0.67, 95% CI 0.53 to 0.84; 1170 women, 4 studies; I² statistic = 0%; high quality evidence). These findings were robust over time, with 10-year HR estimates of 0.72 (95% CI 0.57 to 0.92; 925 women, 2 studies) and 0.67 (95% CI 0.53 to 0.83; 925 women, 2 studies) for OS and PFS, respectively (high quality evidence). The risk of death at 10 years follow-up favoured the adjuvant chemotherapy arm (0.76, 95% CI 0.62 to 0.94; 923 women, 2 studies; I² statistic = 0%), as did the findings for risk of progression at 10 years (RR 0.72, 95% CI 0.60 to 0.87; 925 women, 2 studies; I² statistic = 0%). Low quality evidence suggested that women with high-risk disease may have the most to gain from adjuvant chemotherapy. However, subgroup analyses could neither confirm nor exclude survival benefits in lower risk disease or in optimally staged disease. We found insufficient data to compare adverse events and long term risks between chemotherapy and observation groups.

AUTHORS' CONCLUSIONS

High-quality evidence indicates that adjuvant platinum-based chemotherapy is effective in prolonging survival in women with early stage (FIGO stage I/IIa) epithelial ovarian cancer. It remains uncertain whether women with low- and intermediate-risk early stage disease will benefit as much from adjuvant chemotherapy as women with high-risk disease. Decisions to use adjuvant chemotherapy (AC) in these women should be mindful of this uncertainty, and the uncertainty regarding adverse events. Treatment of women with lower risk disease should be individualised to take into account individual factors.

A novel angiopoietin-2 selective fully human antibody with potent anti-tumoral and anti-angiogenic efficacy and superior side effect profile compared to Pan-Angiopoietin-1/-2 inhibitors

There is increasing experimental evidence for an important role of Angiopoietin-2 (Ang-2) in tumor angiogenesis and progression. In addition, Ang-2 is up-regulated in many cancer types and correlated with poor prognosis. To investigate the functional role of Ang-2 inhibition in tumor development and progression, we generated novel fully human antibodies that neutralize specifically the binding of Ang-2 to its receptor Tie2. The selected antibodies LC06 and LC08 recognize both rodent and human Ang-2 with high affinity, but LC06 shows a higher selectivity for Ang-2 over Ang-1 compared to LC08 which can be considered an Ang-2/Ang-1 cross-reactive antibody. Our data demonstrate that Ang-2 blockade results in potent tumor growth inhibition and pronounced tumor necrosis in subcutaneous and orthotopic tumor models. These effects are attended with a reduction of intratumoral microvessel density and tumor vessels characterized by fewer branches and increased pericyte coverage. Furthermore, anti-Ang-2 treatment strongly inhibits the dissemination of tumor cells to the lungs. Interestingly, in contrast to the Ang-2/Ang-1 cross-reactive antibody LC08 that leads to a regression of physiological vessels in the mouse trachea, the inhibition with the selective anti-Ang-2 antibody LC06 appears to be largely restricted to tumor vasculature without obvious effects on normal vasculature. Taken together, these data provide strong evidence for the selective Ang-2 antibody LC06 as promising new therapeutic agent for the treatment of various cancers.

Synthetic strategies to terpene quinones/hydroquinones

The cytotoxic and antiproliferative properties of many natural sesquiterpene-quinones and -hydroquinones from sponges offer promising opportunities for the development of new drugs. A review dealing with different strategies for obtaining bioactive terpenyl quinones/hydroquinones is presented. The different synthetic approches for the preparation of the most relevant quinones/hydroquinones are described.