The clinical activity of cyproterone acetate in advanced ovarian carcinoma. A London Gynaecology Oncology Group Study

Abiraterone in patients with recurrent epithelial ovarian cancer: principal results of the phase II Cancer of the Ovary Abiraterone (CORAL) trial (CRUK - A16037)

BACKGROUND

Recurrent epithelial ovarian cancer (EOC) remains difficult to treat, with an urgent need for more therapy options. Androgens bind to the androgen receptor (AR), commonly expressed in EOC. CYP17 inhibitor abiraterone irreversibly inhibits androgen biosynthesis. The Cancer of the Ovary Abiraterone (CORAL) trial was designed to evaluate the clinical activity of abiraterone in EOC.

PATIENTS & METHODS

CORAL was a multi-centre, open-label, non-randomised, 2-stage phase II clinical trial. Eligible patients had progression within 12 months of last systemic therapy and no prior hormonal anti-cancer agents. Patients received abiraterone 1000 mg daily plus 5 mg prednisone until progression. The primary endpoint was objective response rate (ORR) according to combined Response Evaluation Criteria in Solid Tumours/Gynaecological Cancer Intergroup (RECIST/GCIG) criteria at 12 weeks. Secondary endpoints included clinical benefit rate (CBR) at 12 weeks.

RESULTS

A total of 42 patients were recruited; median age 65 (range 34-85) years; 37 (88.1%) had high-grade serous tumours; 20 (48%) had at least three prior lines of therapy; 29/40 (72.5%) were AR+. In stage 1, 1/26 response was observed (in an AR+, low-grade serous EOC); response lasted 47 weeks. Overall, 12 week ORR was 1/42 (2%), CBR was 11/42 (26%) (8/29 (28%) in AR+ patients). Disease control was ⩾6 months for 4/29 (14%). One patient (AR+, low-grade serous) had a RECIST response at 82 weeks. Four (10%) had grade ⩾3 hypokalaemia; 11 (26%) had dose delays.

CONCLUSIONS

CORAL represents the first trial of an AR targeted agent in ovarian cancer. While responses were rare, a subset of patients achieved sustained clinical benefit. Targeting AR in EOC including low-grade serous cancer warrants further investigation.

TRIAL REGISTRATION

CORAL is registered on the ISRCTN registry: ISRCTN63407050; http://www.isrctn.com/ISRCTN63407050.

Current drug treatment guidelines for epithelial ovarian cancer

The management of ovarian cancer is developing rapidly with the improvements in specialist multidisciplinary care. Most patients present with advanced disease and require careful surgical debulking followed by platinum-based chemotherapy. The recent introduction of paclitaxel appears to have improved the prognosis of advanced ovarian cancer by an increment that is similar in size to that seen after the introduction of cisplatin in the 1970s. Further clinical trials are required to define the optimum combination and dose of the platinum and taxane analogues, and to establish the role of the many new agents currently undergoing clinical testing. Useful chemotherapy for second-line treatment in platinum-refractory patients is now available, which, combined with more aggressive surgical management, is leading to modest improvements in survival. Improvements in supportive care have enabled increasingly intensive chemotherapy to be given safely. Bone marrow support and inhibitors of specific organ toxicities are likely to be incorporated into treatment protocols over the next decade. The impact of these treatments on patients' quality of life and the economic consequences of a more active approach to management will require careful evaluation.

Cyproterone. A review of its pharmacology and therapeutic efficacy in prostate cancer

Cyproterone (cyproterone acetate) is a steroidal antiandrogenic agent that inhibits the action of adrenal and testicular androgens on prostatic cells. Additionally, its progestogenic activity causes a centrally mediated reduction in testicular secretion of androgens. Studies have demonstrated the effectiveness of cyproterone monotherapy in patients with prostate cancer, and for those in whom orchiectomy is not an acceptable option cyproterone may be a useful alternative. In addition, the drug may be administered in combination with surgical or gonadotrophin-releasing hormone (GnRH) agonist-mediated castration to ensure ablation of adrenal androgens. However, the effectiveness of cyproterone in combination with these forms of testicular androgen deprivation remains to be fully established. Trials to date have not demonstrated prolonged survival in patients receiving the combination therapy. Importantly, however, cyproterone does prevent acute exacerbation of disease during initial treatment with a GnRH agonist. Furthermore, combination therapy tends to be associated with a lower incidence of hot flushes than GnRH agonist-mediated or surgical castration alone. Thus, cyproterone 200 mg/day has proven efficacy in preventing acute flare of disease and reducing the incidence of hot flushes associated with GnRH agonist therapy or orchiectomy. It may also facilitate maximal androgen deprivation in patients receiving GnRH agonist therapy. If this drug is used as monotherapy, dosages of 250 mg/day or greater will probably be required.

Phase II trial of flutamide in advanced ovarian cancer: an EORTC Gynaecological Cancer Cooperative Group study

New active non-toxic therapeutic regimens are warranted in ovarian cancer relapsing after platinum-based chemotherapy. Some investigators have determined that androgen receptors predominated over oestrogen and progesterone receptors in untreated common epithelial ovarian cancer tissue cytosols. In an effort to test its antitumoural activity, 68 pretreated patients with epithelial ovarian cancer were given flutamide 750 mg/day orally for at least 2 months. Of 32 patients who received a minimum of 2 months of therapy, pretreated with at least one platinum-based chemotherapy, and a median of two chemotherapy regimens, two (6.3%) objective responses (one complete and one partial) and nine (28%) disease stabilisations were observed; these lasted 44 and 72 weeks, respectively (for the complete and partial response), and for a median of 24 weeks for stabilisations (range 12-48+). Nausea and vomiting were the most frequent side-effects. These occurred in 19/55 (34.5%) patients evaluable for toxicity. Flutamide has to be considered ineffective in patients extensively pretreated with chemotherapy, and it is not devoid of side-effects.