Workshop: options for therapy in ovarian cancer

Cost-Effectiveness of Niraparib and Olaparib as Maintenance Therapy for Patients with Platinum-Sensitive Recurrent Ovarian Cancer

BACKGROUND

The recent approval of olaparib and niraparib as maintenance therapy can significantly affect the management of ovarian cancer. Clinical benefits, however, come with trade-offs in adverse events and costs.

OBJECTIVE

To evaluate the cost-effectiveness of new ovarian cancer poly-ADP ribose polymerase (PARP) inhibitor therapies, olaparib and niraparib, as maintenance therapy for patients with platinum-sensitive recurrent ovarian cancer.

METHODS

A decision tree model was constructed to evaluate the costs and effectiveness of olaparib and niraparib compared with placebo from a U.S. health care sector perspective. Costs included drug costs and costs of disease monitoring and management of adverse events throughout the treatment course. Costs were estimated from RED BOOK, Medicare reimbursement rates, and the literature and reported in 2017 U.S. dollars. Clinical effectiveness was measured in progression-free survival (PFS) life-years based on clinical trial results (NCT00753545, NCT01874353, and NCT01847274). The incremental cost-effectiveness ratio (ICER) was computed by dividing the incremental cost by the incremental effectiveness.

RESULTS

At base case, niraparib was the more effective treatment option with slightly higher PFS, followed by olaparib. The ICERs for niraparib and olaparib compared with common baseline placebo were $235K and $287K per PFS life-year, respectively, with olaparib extended-dominated by niraparib. Both drugs were associated with lower ICERs in patients with a gBRCA mutation than in patients without a gBRCA mutation. One-way sensitivity analysis suggested that drug prices and PFS could affect ICERs significantly, but the ICERs remained above $100K per PFS life-year within the plausible ranges of all parameters. Probabilistic sensitivity analysis suggested that niraparib was associated with higher net benefits compared with placebo only when willingness-to-pay (WTP) values were above $210K per PFS life-year thresholds.

CONCLUSIONS

PARP inhibitors niraparib and olaparib will extend PFS in platinum-sensitive recurrent ovarian cancer patients but are also associated with high drug acquisition costs. The base case ICERs were around or above $250K per PFS life-year in this model. No formal cost-effectiveness WTP threshold for health technology assessment exists in the United States. At a reference WTP of $100K per PFS life-year, the PARP inhibitors may not be cost-effective options.

DISCLOSURES

This study was unfunded. The authors have nothing to disclose.

Rucaparib maintenance treatment for recurrent ovarian carcinoma after response to platinum therapy (ARIEL3): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Rucaparib, a poly(ADP-ribose) polymerase inhibitor, has anticancer activity in recurrent ovarian carcinoma harbouring a BRCA mutation or high percentage of genome-wide loss of heterozygosity. In this trial we assessed rucaparib versus placebo after response to second-line or later platinum-based chemotherapy in patients with high-grade, recurrent, platinum-sensitive ovarian carcinoma.

METHODS

In this randomised, double-blind, placebo-controlled, phase 3 trial, we recruited patients from 87 hospitals and cancer centres across 11 countries. Eligible patients were aged 18 years or older, had a platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube carcinoma, had received at least two previous platinum-based chemotherapy regimens, had achieved complete or partial response to their last platinum-based regimen, had a cancer antigen 125 concentration of less than the upper limit of normal, had a performance status of 0-1, and had adequate organ function. Patients were ineligible if they had symptomatic or untreated central nervous system metastases, had received anticancer therapy 14 days or fewer before starting the study, or had received previous treatment with a poly(ADP-ribose) polymerase inhibitor. We randomly allocated patients 2:1 to receive oral rucaparib 600 mg twice daily or placebo in 28 day cycles using a computer-generated sequence (block size of six, stratified by homologous recombination repair gene mutation status, progression-free interval after the penultimate platinum-based regimen, and best response to the most recent platinum-based regimen). Patients, investigators, site staff, assessors, and the funder were masked to assignments. The primary outcome was investigator-assessed progression-free survival evaluated with use of an ordered step-down procedure for three nested cohorts: patients with BRCA mutations (carcinoma associated with deleterious germline or somatic BRCA mutations), patients with homologous recombination deficiencies (BRCA mutant or BRCA wild-type and high loss of heterozygosity), and the intention-to-treat population, assessed at screening and every 12 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01968213; enrolment is complete.

FINDINGS

Between April 7, 2014, and July 19, 2016, we randomly allocated 564 patients: 375 (66%) to rucaparib and 189 (34%) to placebo. Median progression-free survival in patients with a BRCA-mutant carcinoma was 16·6 months (95% CI 13·4-22·9; 130 [35%] patients) in the rucaparib group versus 5·4 months (3·4-6·7; 66 [35%] patients) in the placebo group (hazard ratio 0·23 [95% CI 0·16-0·34]; p<0·0001). In patients with a homologous recombination deficient carcinoma (236 [63%] vs 118 [62%]), it was 13·6 months (10·9-16·2) versus 5·4 months (5·1-5·6; 0·32 [0·24-0·42]; p<0·0001). In the intention-to-treat population, it was 10·8 months (8·3-11·4) versus 5·4 months (5·3-5·5; 0·36 [0·30-0·45]; p<0·0001). Treatment-emergent adverse events of grade 3 or higher in the safety population (372 [99%] patients in the rucaparib group vs 189 [100%] in the placebo group) were reported in 209 (56%) patients in the rucaparib group versus 28 (15%) in the placebo group, the most common of which were anaemia or decreased haemoglobin concentration (70 [19%] vs one [1%]) and increased alanine or aspartate aminotransferase concentration (39 [10%] vs none).

INTERPRETATION

Across all primary analysis groups, rucaparib significantly improved progression-free survival in patients with platinum-sensitive ovarian cancer who had achieved a response to platinum-based chemotherapy. ARIEL3 provides further evidence that use of a poly(ADP-ribose) polymerase inhibitor in the maintenance treatment setting versus placebo could be considered a new standard of care for women with platinum-sensitive ovarian cancer following a complete or partial response to second-line or later platinum-based chemotherapy.

FUNDING

Clovis Oncology.

Review role of topotecan in gynaecological cancers: current indications and perspectives

BACKGROUND

Ovarian cancer is the fourth cause of death from gynaecological cancer and cervical cancer is the first in women <45 years old in developing countries. The aim of this article is to review the role of topotecan (Hycamtin), a semi-synthetic alkaloid derivative of camptothecin, in ovarian and cervical cancer in monotherapy and in combination.

METHODS

This article reviews the mechanism of action, pharmacokinetics, toxicity and efficacy of topotecan. The paper also reports the principal phases II and III studies of topotecan in advanced or recurrent ovarian and cervical cancer.

RESULTS

Topotecan (Hycamtin), currently indicated for the treatment of relapsed ovarian cancer, has demonstrated activity both in platinum-sensitive and in platinum-resistant disease. The combination cisplatin-topotecan for the treatment of advanced and recurrent cervical cancer has demonstrated a clinical benefit in terms of response rate, overall survival and progression free survival. Haematological toxicity of topotecan also is easy to manage and not cumulative, especially with the weekly scheduled recently introduced in clinical practice.

CONCLUSION

Topotecan (Hycamtin) will continue to play a role in the treatment of advanced ovarian and cervical cancer, in monotherapy or in combination with other cytotoxic agents.

Gemcitabine and pegylated liposomal doxorubicin alternating with cisplatin plus cyclophosphamide in platinum refractory/resistant, paclitaxel-pretreated, ovarian carcinoma

OBJECTIVES

This phase II study conducted to investigate the efficacy and toxicity of the combination of gemcitabine (GEM) and pegylated liposomal doxorubicin (LDOX) alternating with cisplatin (CDDP) and cyclophosphamide (CTX) in platinum-resistant/refractory, paclitaxel pretreated epithelial ovarian cancer (EOC).

PATIENTS AND METHODS

Forty-eight patients with CDDP-resistant/refractory and paclitaxel pretreated patients were treated with 8 cycles of GEM 800 mg/m2 days 1 and 8 and LDOX 30 mg/m2 day 1, alternating with CDDP 60 mg/m2 and CTX 600 mg/m2 every 3 weeks.

RESULTS

Objective responses were observed in 37.5% of patients (4 complete and 11 partial responses) with measurable disease (n=40). CA125 response occurred in 30 (71.4%) of patients with elevated CA125 (n=42). After a median follow-up of 23 months, the median progression-free survival (PFS) was 6.9 months (95% confidence interval, CI: 5.2-8.5), while the median overall survival (OS) was 18.2 months (95% CI: 12.7-23.6). A progression-free interval (PFI) of 0-3 months was associated with lower objective responses (10% versus 46.6%, p=0.06). Chemotherapy was well tolerated. The most frequent toxicities were myelosuppression, neurotoxicity, nephrotoxicity, nausea/vomiting, fatigue and palmar-plantar erythrodysesthesia (PPE). Overall 31 (65%) patients received G-CSF and 13 (27%) antibiotics because of neutropenia and/or febrile neutropenia.

CONCLUSION

This alternating combination chemotherapy is feasible for patients with platinum-resistant EOC and is associated with encouraging outcomes and a favorable toxicity profile.

Optimal therapy for platinum-resistant recurrent ovarian cancer: doxorubicin, gemcitabine or topotecan?

Ovarian cancer is more fatal than all the other gynaecological malignancies combined. Although most patients respond to first-line combination chemotherapy, the vast majority (50-75%) of patients with advanced disease will relapse. The management of patients with recurrent ovarian cancer is based on their response profile to platinum: patients with platinum-sensitive disease can be rechallenged with platinum-based chemotherapy, whereas the management of patients with platinum-resistant or -refractory disease remains an area of active investigation. In this review, the data for second-line therapy in this latter group of patients will be summarised and recommendations for their optimal management will be made.

Microvessel density in ovarian carcinoma: computer image analysis in patients with shorter and longer survival

We previously reported that tumor microvessel density (MVD) may have prognostic significance in ovarian carcinoma. The aim of this study was to compare the intratumoral microvessels using a computer-aided image analysis system between FIGO stage IIIC, serous, G3, ovarian carcinomas obtained from living patients who had no evident disease 5 years after primary treatment and ovarian carcinomas, matched for stage, histopathology, grade of differentiation, and treatment, obtained from patients who had died of progression of disease no later than 1 year after primary treatment. We observed that MVD is statistically correlated, according to the logistic regression in univariate and multivariate ways, with the survival (P= 0.03 and P= 0.05, respectively) and with the progression of the disease during first-line chemotherapy (P= 0.009 and P= 0.012, respectively). In the past years, the modulation of first-line chemotherapeutic treatment has been a question of discussion, because the oncologist observes extremely unpredictable behaviors with surprisingly long survivals and also short survivals. Pathologists may give clinicians some additional prognostic information useful in the management of ovarian carcinoma patients. The results of this study support the hypothesis that the evaluation of MVD with computer image analysis can help clinicians in the choice of the tailored treatment of the single case.

In vitro and in vivo characterization of a novel biocompatible polymer–lipid implant system for the sustained delivery of paclitaxel

Recently, a novel chitosan-based implantable formulation (chitosan-ePC) was developed to provide controlled, local release of paclitaxel (PTX) for the treatment of ovarian tumors. Hence, the objective of this study was to evaluate this delivery system in vitro in human ovarian SKOV-3 cells and in vivo in mice with intraperitoneal implants of drug-free or 14C-PTX-chitosan-ePC films. In vitro, 14C-PTX-chitosan-ePC implants (10 mg) provided zero-order constant release of 0.92+/-0.03 pg/day PTX over 5 days. Released PTX retained dose-dependent activity; effectively inhibiting SKOV-3 proliferation with an ED50 of 211 ng/ml of released PTX. Drug-free implants did not affect cell viability or cell morphology of SKOV-3 cells. A sustained, zero-order release of PTX was also seen in vivo over a 2 week period in mice implanted with 14C-PTX-chitosan-ePC films. Correlations between the in vitro and in vivo release of PTX was highly significant (R2 = 0.975). After 2-4 weeks, mice with chitosan-ePC implants did not demonstrate any signs of encapsulation, inflammation or infection. Overall, our in vitro and in vivo results demonstrated zero-order drug release and biocompatibility of the novel chitosan-ePC film. This indicates potential usefulness of chitosan-ePC implants in the sustained and local delivery of anti-neoplastic agents.

pRb2/p130 decreases sensitivity to apoptosis induced by camptothecin and doxorubicin but not by taxol

PURPOSE

In addition to their original function as cell cycle regulators, retinoblastoma (Rb) family members were recently reported to modulate the sensitivity of cancer cells to chemotherapeutic agents. The purpose of this study is to investigate the possible role of pRb2/p130 in the sensitivity of ovarian cancer to camptothecin, doxorubicin, and taxol.

EXPERIMENTAL DESIGN

pRb2/p130 was overexpressed in the CAOV-3 ovarian cancer cell line, and the effect of pRb2/p130 overexpression on sensitivity to apoptosis trigged by IC(50) doses of different drugs was evaluated by various methods, including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Western blot analyses.

RESULTS

The results reported in this study support the conclusion that overexpression of pRb2/p130 in the CAOV-3 ovarian cancer cell line lacking wild-type p53 is able to inhibit apoptosis triggered by camptothecin and doxorubicin through the c-Jun NH(2)-terminal kinase signaling transduction pathway. Conversely, taxol-induced cell death is not influenced by the pRb2/p130 protein level.

CONCLUSIONS

A careful analysis of pRb2/p130 expression in tumor specimens could help to identify the best clinical protocol to be used for each patient, improving efficacy and tolerance and therefore offering additional progress in the treatment of advanced ovarian cancer.

Salvage temozolomide for prior temozolomide responders

BACKGROUND

Temozolomide (TMZ) often is used as adjuvant or first-line therapy for patients with glioma. Because of potential hematologic complications, it usually is discontinued after 12-18 cycles, even in responders. Subsequent salvage therapies are reported to have limited efficacy at the time of disease recurrence. In the current study, the authors assessed the outcome and complications of reusing TMZ at the time of disease recurrence in patients who previously responded to treatment.

METHODS

A retrospective review of patients with recurrent/progressive glioma who had a history of response to TMZ and were treated with the same agent at the time of disease recurrence was conducted.

RESULTS

Fourteen patients were identified (8 men and 6 women). The median age of the patients was 56 years (range, 25-67 yrs) at the time of diagnosis; 9 patients had glioblastoma, 3 had anaplastic astrocytoma, and 2 patients had low-grade oligodendroglioma. No patient developed disease progression while receiving the initial TMZ treatment. At the time of the initial disease recurrence, 13 patients were readministered TMZ. One patient received TMZ at the time of second disease recurrence. All patients were assessed for radiographic response. Objective response or stable disease was achieved in 6 patients (43%; 95% confidence interval [95% CI], 21-67%) and the 6-month progression-free survival was 36% (95% CI, 16-61%).

CONCLUSIONS

TMZ was found to be well tolerated and effective in this setting, suggesting that repeat use of TMZ in previous responders warrants further investigation.