Phase II study of oxaliplatin in platinum-resistant and refractory ovarian cancer: a gynecologic group study

One- and Two-Photon Activated Release of Oxaliplatin from a Pt(IV)-Functionalized Poly(phenylene ethynylene)

We report a water-soluble poly(phenylene ethynylene) (PPE-Pt(IV)) that is functionalized with oxidized oxaliplatin Pt(IV) units and its use for photoactivated chemotherapy. The photoactivation strategy is based on photoinduced electron transfer from the PPE backbone to oxaliplatin Pt(IV) as an electron acceptor; this process triggers the release of oxaliplatin, which is a clinically used anticancer drug. Mechanistic studies carried out using steady-state and time-resolved fluorescence spectroscopy coupled with picosecond-nanosecond transient absorption support the hypothesis that electron transfer triggers the drug release. Photoactivation is effective, producing oxaliplatin with a good chemical yield in less than 1 h of photolysis (400 nm, 5 mW cm-2). Photorelease of oxaliplatin from PPE-Pt(IV) can also be effected with two-photon excitation by using 100 fs pulsed light at 725 nm. Cytotoxicity studies using SK-OV-3 human ovarian cancer cells demonstrate that without photoactivation PPE-Pt(IV) is not cytotoxic at concentrations up to 10 μM in polymer repeating unit (PRU) concentration. However, following a short period of 460 nm irradiation, oxaliplatin is released from PPE-Pt(IV), resulting in cytotoxicity at concentrations as low as 2.5 μM PRU.

Oxaliplatin plus leucovorin and 5-fluorouracil (FOLFOX-4) as a salvage chemotherapy in heavily-pretreated platinum-resistant ovarian cancer

Background

The purpose of this study was to evaluate the clinical impact of oxaliplatin, leucovorin, and 5-fluorouracil (FOLFOX-4) chemotherapy in terms of the response rate, progression-free/overall survival (PFS/OS) and safety profile in patients with heavily pretreated recurrent epithelial ovarian cancer.

Methods

Clinical data were reviewed in 29 patients who received FOLFOX-4 as more than third-line chemotherapy, consisting of 85 mg/m² of oxaliplatin, 200 mg/m² of leucovorin, and bolus 400 mg/m² on day 1 of 5-fluorouracil, followed by a 22-h infusion of 600 mg/m² of 5-fluorouracil for 2 consecutive days every 3 weeks. We also compared the efficacy and toxicity of FOLFOX-4 with that of topotecan, a standard treatment, given at a dosage of 1.5 mg/m² every three weeks in 26 patients.

Results

The median age of enrolled patients was 60 years (range 33 to 85). A median of 4 cycles (range 1–17) of FOLFOX-4 were administered. Complete response and partial response were observed in one (3.5%) and 5 (17.2.2%) patients, respectively, while stable disease was reported in 8 (27.6%) patients. Among all patients, grade 3–4 anemia, neutropenia, and thrombocytopenia were observed in 0 (0%), 5 (17.2%), and 3 (10.3%) cases, respectively. Grade 3–4 fatigue was recorded in one (3.4%) patient and diarrhea in 2 (6.9%). Median PFS and OS were 2.8 months [95% confidence interval (CI) 1.7–4.9] and 6.2 months (95% CI 2.4–14.6), respectively. No significant differences in terms of efficacy and toxicity were observed between patients receiving FOLFOX-4 and those treated with topotecan.

Conclusions

The FOLFOX-4 regimen would seem to obtain similar survival rates to those of standard therapy with topotecan in platinum-resistant ovarian cancer. Further randomized trials are warranted to confirm our findings.

Salvage chemotherapy with the combination of oxaliplatin, leucovorin, and 5-fluorouracil in advanced gastric cancer refractory or intolerant to fluoropyrimidines, platinum, taxanes, and irinotecan

BACKGROUND

Although nivolumab showed survival benefit in patients with advanced gastric cancer (AGC) progressing after standard chemotherapy, there is a lack of data regarding oxaliplatin-based chemotherapy in this clinical setting.

METHODS

We retrospectively evaluated the efficacy and safety of oxaliplatin with l-leucovorin and bolus/continuous infusion of 5-fluorouracil as salvage treatment in patients with AGC refractory or intolerant to fluoropyrimidines, cisplatin, taxanes, and irinotecan.

RESULTS

Overall, 50 patients treated between December 2009 and December 2013 were included in this analysis. The overall response rate (ORR) was 21.2% among 33 patients with measurable disease. The median time to treatment failure (TTF) and overall survival (OS) were 2.4 and 4.2 months. In multivariate analysis, factors associated with OS included poor performance status [hazard ratio (HR) 3.20; 95% confidence interval (CI) 1.55-6.60], shorter time from the start of first-line therapy (HR 2.20; 95% CI 1.18-4.12), and higher neutrophil/lymphocyte ratio value (HR 4.87; 95% CI 2.32-10.25). In patients (n = 35) with at most one risk factor, the ORR, median TTF, and OS were 26.1%, 3.6, and 6.7 months, respectively. The most common grade 3 or 4 adverse events were neutropenia (30%), anemia (22%), febrile neutropenia (8%), and peripheral neuropathy (8%). Initial and subsequent dose reduction was performed in 18 (36%) and 23 (46%) patients. There was one treatment-related death caused by septic infection.

CONCLUSIONS

Salvage chemotherapy with the combination of oxaliplatin, leucovorin, and 5-fluorouracil has a potential activity and is tolerable for heavily treated AGC with appropriate dose modification and patient selection.

Overcoming platinum resistance in ovarian cancer treatment: from clinical practice to emerging chemical therapies

INTRODUCTION

The objective of this review is to summarize results from clinical trials that tested cytotoxic drugs and target strategies for the treatment of platinum resistant (PR) recurrent ovarian cancer (ROC) with particular attention to Phase III and ongoing trials. Areas covered: Since platinum free interval (PFI) represents the most important predictive factor for response to platinum re-treatment in ROC, non-platinum regimens are conventionally considered the most appropriate approaches. Impressive progress has been made in recent decades, resulting in the identification of most effective cytotoxic agents and in the development of new target strategies. However, the efficacy of most of these drugs for the treatment of PR disease is still limited. Expert opinion: The most favorable benefit for the treatment of PR disease, has been described by the AURELIA trial that showed a 3.3 months increase in progression free survival (PFS) when bevacizumab was combined with non-platinum single agent chemotherapy in bevacizumab-naïve patients. Nevertheless, the use of novel agents is associated to important costs for just little gains in survival. Thus, in our opinion the economic evaluation, such as the incorporation of quality of life into the clinical studies is crucial for the development of future trials for PR-ROC.

Outcome of recurrent uterine papillary serous carcinoma treated with platinum-based chemotherapy

OBJECTIVE

The aim of this study was to estimate the outcome and response to platinum-based chemotherapy (CT) in patients with recurrent uterine papillary serous carcinoma (UPSC).

METHODS

Patients with recurrent UPSC from 2000 to 2012 were included retrospectively. All patients received platinum-based CT for recurrent disease. Platinum-free interval was divided into less than 6 months (platinum resistant) and 6 months or longer (platinum sensitive).

RESULTS

Twenty-two patients with recurrent UPSC were included. The median age was 66.5 years. The majority of the patients initially presented with advanced-stage disease (68%). A total of 84% (18/22) received adjuvant CT; all regimens were platinum based.The overall response rate (RR) and stable disease were 50% and 36.4%. The mean duration of response and stable disease were 9.4 and 5.6 months. Among the platinum-sensitive group, the overall RR was 64.7% compared with 0% in the platinum-resistant group. Among the patients who received prior adjuvant platinum-based CT, the RR was 38.8% compared with 100% among those who did not receive adjuvant CT. When stratified by platinum-based regimen, those who received the platinum-taxane regimen had a higher RR compared with those who received the platinum-gemcitabine regimen (62.5% vs 20%) among those who received prior adjuvant platinum therapy. The median progression-free survival and overall survival for the entire cohort were 8.4 and 24.9 months, respectively. The median progression-free survival was significantly longer for platinum-sensitive disease compared with platinum-resistant disease (10.2 vs 3.3 months, respectively; P = 0.002). Similarly, the median overall survival was longer for platinum-sensitive disease compared with platinum-resistant disease (27.1 vs 13.7 months, respectively). However, this difference was not statistically significant (P = 0.15).

CONCLUSIONS

Platinum-based CT is an active regimen in recurrent UPSC even if patients received prior adjuvant platinum CT. Platinum-free interval predicts response and outcome of platinum-based CT in recurrent setting such as in ovarian cancer. Plantinum-taxane is more active than platinum-gemcitabine in recurrent UPSC.

Chemotherapy for Late-Stage Cancer Patients: Meta-Analysis of Complete Response Rates

Complete response (CR) rates reported for cytotoxic chemotherapy for late-stage cancer patients are generally low, with few exceptions, regardless of the solid cancer type or drug regimen. We investigated CR rates reported in the literature for clinical trials using chemotherapy alone, across a wide range of tumour types and chemotherapeutic regimens, to determine an overall CR rate for late-stage cancers. A total of 141 reports were located using the PubMed database. A meta-analysis was performed of reported CR from 68 chemotherapy trials (total 2732 patients) using standard agents across late-stage solid cancers—a binomial model with random effects was adopted. Mean CR rates were compared for different cancer types, and for chemotherapeutic agents with different mechanisms of action, using a logistic regression. Our results showed that the CR rates for chemotherapy treatment of late-stage cancer were generally low at 7.4%, regardless of the cancer type or drug regimen used. We found no evidence that CR rates differed between different chemotherapy drug types, but amongst different cancer types small CR differences were evident, although none exceeded a mean CR rate of 11%. This remarkable concordance of CR rates regardless of cancer or therapy type remains currently unexplained, and motivates further investigation.

Phase I study of intravenous (IV) docetaxel and intraperitoneal (IP) oxaliplatin in recurrent ovarian and fallopian tube cancer

OBJECTIVE

The primary objective was to define the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of IV docetaxel and IP oxaliplatin in women with recurrent ovarian (OV), fallopian tube (FT) or peritoneal (PP) cancer. Secondary objectives included response rate, time to progression, pharmacokinetics (PK) and quality of life (QoL).

METHODS

Patients received docetaxel 75mg/m(2) IV day (d) 1 and oxaliplatin escalating from 50mg/m(2) IP d2 every 3weeks using a 3+3 design. Treatment continued until disease progression, remission, or intolerable toxicity. Plasma and IP samples were taken to determine drug concentrations. MD Anderson Symptom Inventory and symptom interference scale were completed weekly.

RESULTS

Thirteen patients were included. Median number of cycles was 6 (range 1-10). Ten patients had measureable disease. Best response was partial response (PR-2), stable disease (SD-7), and progressive disease (PD-1). Twenty-one Grades 3-4 toxicities were noted, commonly hematologic. Two patients had DLTs: prolonged neutropenia (1) and abdominal pain (1). MTD was d1 docetaxel 75mg/m(2) IV and d2 oxaliplatin 50mg/m(2) IP. Symptom burden peaked week one and returned to baseline by week two of each cycle on dose level 1. Dose level 2 had persistently high symptom burden and interference. At IP oxaliplatin doses of 50mg/m(2), total unbound drug exposure (AUC) averaged 8 times larger and Cmax reached concentrations 50-fold greater in IP fluid compared to plasma.

CONCLUSIONS

Docetaxel 75mg/m(2) IV d1 and oxaliplatin 50mg/m(2) IP d2 is the MTD. Most patients had PR or SD. Patient-reported outcomes demonstrate temporary but tolerable decrements in QoL. IP oxaliplatin provides PK advantages over IV administration.

Rapamycin enhanced the antitumor efficacy of oxaliplatin in cisplatin-resistant ovarian cancer cells A2780cis both in vitro and in vivo

OBJECTIVE

This study aimed to investigate the efficacy of combination of rapamycin, an mammalian target of rapamycin (mTOR) inhibitor for treating rejection after organ transplantation, and oxaliplatin, a third-generation of platinum drug usually used to treat chemoresistant or progressive ovarian cancer, in cisplatin-resistant ovarian carcinoma cells A2780cis.

METHODS/MATERIALS

Expressions of mTOR and its target molecules p70S6K and 4E-BP1 were determined in cisplatin-sensitive and -resistant cells A2780 and A2780cis, respectively, using Western blotting. Proliferation of A2780cis exposure to oxaliplatin or oxaliplatin plus rapamycin was examined using MTT assay in vitro as well as a nude mice model in vivo. Cell apoptosis and proapoptosis proteins including caspase-8 and -3 and PARP were determined using flow cytometry and Western blotting.

RESULTS

We found that A2780cis cells had partial cross-resistance between cisplatin and oxaliplatin. The levels of phosphorylated mTOR (p-mTOR), p70S6K, and 4E-BP1 were significantly increased in A2780cis cells compared to A2780 cells, which might be implicated in cisplatin-induced chemoresistance. Rapamycin obviously enhanced the inhibitory effect of oxaliplatin on the growth of A2780cis both in vitro and in vivo. Rapamycin slightly induced cell apoptosis but significantly enhanced the effect of oxaliplatin in soliciting apoptosis of A2780cis cells, which might be ascribed to its ability in further increasing the levels of cleaved caspase-8 and -3 and PARP induced by oxaliplatin.

CONCLUSION

These results suggested that combination of oxaliplatin and rapamycin enhanced the antitumour efficacy of oxaliplatin in A2780cis cells and therefore might have a role in treating cisplatin-resistant ovarian carcinoma.

Gemcitabine-oxaliplatin (GEMOX) as salvage treatment in pretreated epithelial ovarian cancer patients

Background

Currently, no clearly superior management strategy exists for recurrent, platinum-resistant ovarian cancer. We tested the efficacy and safety of gemcitabine combined with oxaliplatin (GEMOX) in a multicentre phase II clinical trial.

Methods

Forty one patients with recurrent, platinum-resistant ovarian cancer were enrolled. Prior to study entry, all the participants had received at least one platinum-based regimen. Gemcitabine was administered at 1000 mg/m² as protracted infusion (100 min) on day 1, and oxaliplatin at the dose of 100 mg/m² on day 2 in a 2 hour infusion. Cycles were repeated every two weeks.

Results

We observed an overall response rate of 37% [95% Confidence Interval (CI), 22.3–51.7]. Objective responses plus disease stabilization (clinical benefit) occurred in 78% of patients. Median progression-free survival was 6.8 months (95% CI, 5.8–7.8), and median overall survival was 16.5 months (95% CI, 12.2–20.8). Median time to self-reported symptom relief, which was described by 22 out of 27 symptomatic patients (81.5%), was 4 weeks (range, 2–8). Grade 4 neutropenia and febrile neutropenia were observed in 2 (5%) and 1 (2.5%) patients, while grade 3 anemia was encountered in 2 (5%) patients, respectively. The most common adverse effects of any grade were gastrointestinal symptoms, fatigue and neutropenia. Nine patients (22%) experienced mild allergic reaction to oxaliplatin, with no treatment discontinuation.

Conclusions

In our cohort of recurrent, platinum-resistant ovarian cancer patients, GEMOX showed encouraging activity and manageable toxicity. Under circumstances requiring a rapid disease control, this combination regimen may offer a particularly viable option, particularly in heavily pretreated patients.

Evolution of the Gynecologic Oncology Group protocols in the treatment of epithelial ovarian cancer

This chapter reviews some of the sentinel Gynecologic Oncology Group (GOG) ovarian trials, describes their rationale, provides summary tables for reference, and is organized into early ovarian cancer (GOG 1, 7601, 7602, 95, 157, 175, 212), advanced ovarian cancer optimal (2, 25, 52, 104, 114, 158, 172, 182, 178, 212, 252), and suboptimal disease (3, 22, 47, 97, 111, 162, 182, 218, 252, 262).

Phase II trial of the mTOR inhibitor, temsirolimus and evaluation of circulating tumor cells and tumor biomarkers in persistent and recurrent epithelial ovarian and primary peritoneal malignancies: a Gynecologic Oncology Group study

OBJECTIVE

Patients with persistent/recurrent epithelial ovarian cancer/primary peritoneal cancer (EOC/PPC) have limited treatment options. AKT and PI3K pathway activation is common in EOC/PPC, resulting in constitutive activation of downstream mTOR. The GOG conducted a phase II evaluation of efficacy and safety for the mTOR inhibitor, temsirolimus in EOC/PPC and explored circulating tumor cells (CTC) and AKT/mTOR/downstream tumor markers.

METHODS

Eligible women with measurable, persistent/recurrent EOC/PPC who had received 1-3 prior regimens were treated with 25mg weekly IV temsirolimus until progression or intolerable toxicity. Primary endpoints were progression-free survival (PFS) ≥6-months, tumor response, and toxicity. CellSearch® system was used to examine CTC, and AKT/mTOR/downstream markers were evaluated by archival tumor immunohistochemistry. Kendall's tau-b correlation coefficient (r) and Cox regression modeling were used to explore marker associations with baseline characteristics and outcome.

RESULTS

Sixty patients were enrolled in a two-stage sequential design. Of 54 eligible and evaluable patients, 24.1% (90% CI 14.9%-38.6%) had PFS ≥6 months (median 3.1 months), 9.3% (90% CI 3.7%-23.4%) experienced a partial response. Grade 3/4 adverse events included metabolic (8), gastrointestinal (8), pain (6), constitutional (5) and pulmonary (4). Suggested associations were between cyclin D1 and PFS ≥6 months, PFS or survival; positive CTC pre-treatment and lack of response; and high CTC expression of M30 and PFS ≥6 months/longer PFS.

CONCLUSIONS

Temsirolimus appears to have modest activity in persistent/recurrent EOC/PPC; however, PFS is just below that required to warrant inclusion in phase III studies in unselected patients. Cyclin D1 as a selection marker and CTC measures merit further study.

Management strategies for recurrent platinum-resistant ovarian cancer

Although ovarian cancer is often a chemosensitive malignancy, patients who are resistant to platinum-based chemotherapy represent a therapeutic challenge. Currently, the only drugs that are US FDA approved to treat this subset of patients are paclitaxel, pegylated liposomal doxorubicin (PLD) and topotecan. The response rates with these agents is in the 10-15% range and overall survival is around 12 months. Other drugs that have shown some activity in platinum-resistant ovarian cancer include the taxane analogues, oral etoposide, pemetrexed and bevacizumab. Unfortunately, randomized phase III trials of second-line chemotherapy in patients with platinum-resistant ovarian cancer have not shown an advantage over existing therapy with respect to progression-free survival or overall survival. The only trial that has reported a significant progression-free survival advantage over standard therapy is a randomized phase II trial of PLD with or without EC145, a folate-linked vinca alkaloid. Final survival results of this trial are pending.

A Gynecologic Oncology Group phase II trial of the protein kinase C-beta inhibitor, enzastaurin and evaluation of markers with potential predictive and prognostic value in persistent or recurrent epithelial ovarian and primary peritoneal malignancies

OBJECTIVES

Protein kinase C (PKC) activation contributes to proliferation and angiogenesis in epithelial ovarian or primary peritoneal carcinoma (EOC/PPC). A multi-institutional phase II trial was conducted to evaluate the efficacy and safety of PKCβ inhibitor enzastaurin in persistent or recurrent EOC/PPC and to explore potential prognostic and predictive biomarkers.

METHODS

Eligible women with measurable platinum-sensitive and resistant EOC/PPC were treated with continuous administration of oral enzastaurin until disease progression or unacceptable toxicity. A two-stage sequential design was used to evaluate progression-free survival (PFS) ≥6-months, tumor response, and toxicity. Translational studies included sequencing of the TP53, PTEN, PIK3CA and PKCβII genes for somatic mutations, quantitative PCR assays for AKT2 and PTEN copy number alterations, and measurement of circulating VEGF-A plasma levels.

RESULTS

Among 27 eligible and evaluable patients, 3 women with PFS≥6-months (11%) and 2 women with partial responses (7%) were observed. One of them achieved a durable response and remains on the study. No grade 4 adverse events were observed. Most common grade 3 adverse events were constitutional (4) and gastrointestinal (3). Mutations in the TP53 gene and abnormal copy number in the PTEN gene were common (56% and 48% of cases, respectively).

CONCLUSIONS

Enzastaurin was tolerable but had insufficient activity to proceed with the second stage of accrual. However, 1 patient has been progression-free for 44 months. No association between a biomarker and response to enzastaurin has been found. Exploratory analysis suggested an association between survival and PTEN copy number losses.

Characterization of two independent, exposure-time dependent paclitaxel-resistant human ovarian carcinoma cell lines

This experiment was conducted to address the question of whether acquired paclitaxel resistance is dependent upon whether it is given as a single brief exposure or as a long-term exposure. PX2 and PX24 were established from 2008 human ovarian cancer cells by 2-h single exposure or 24-h continuous exposure to paclitaxel. PX2 acquired paclitaxel resistance faster than PX24 by twofold. Drug resistant pattern was exposure-time dependent. In 2-h exposure, PX2 showed 53.86 ± 4.96 (mean ± standard deviation [SD]) fold paclitaxel resistance while PX24 showed 9.51 ± 1.01 fold resistance (P = 0.002). In 24-h exposure, PX2 showed 2.31 ± 0.3 fold paclitaxel resistance while PX24 showed 28.17 ± 0.98 fold resistance (P = 0.040). PX2 and PX24 acquired cross-resistance to docetaxel and SN38 and the resistance degrees were significantly higher in PX2 than PX24. They displayed approximately twofold cisplatin collateral sensitivity. PX24 also displayed sensitivity to other platinum drugs, oxaliplatin and ZD0473, whereas PX2 acquired significant resistance to both of them. Although differential tubulin-isotype expressions were noted among 2008, PX2 and PX24, they were not significant. In electron microscopy, prominent, densely stained lysosomes were observed more in the resistant cells than 2008. Two independent, exposure-time dependent paclitaxel-resistant human ovarian carcinoma cell lines were established. Understanding the characteristics of the differential resistance pattern could be clinically beneficial for the selection of second line chemotherapy for relapsed ovarian cancer.

Targeted treatment of recurrent platinum-resistant ovarian cancer: current and emerging therapies

With advances in surgical techniques and chemotherapeutic agents, mortality rates from epithelial ovarian cancer (EOC) have slightly decreased over the last 30 years. However, EOC still ranks as the most deadly gynecologic cancer with an overall 5-year survival rate of 45%. Prognosis is especially disappointing for women with platinum-resistant disease, where 80% of patients will fail to respond to available therapies. Emerging treatment strategies have sub-sequently focused on targets which are integral to tumor growth and metastasis. In this review, we will focus on those innovative agents currently under investigation in clinical trials.

Trials with impact on clinical management: first line

INTRODUCTION

Advanced-stage epithelial ovarian cancer is generally managed with cytoreductive surgery and chemotherapy consisting of carboplatin and paclitaxel. Although initially responsive, most tumors recur and demonstrate progressive chemotherapy resistance. During the last 20 years, many thousands of women have participated in international front-line phase 3 trials that have contributed to our understanding of ovarian cancer biology and helped to define optimal treatment strategies. Emerging data from these trials need to be interpreted within an evolving paradigm of cancer biology, disease management, and availability of clinical resources.

METHODS

Survey of recent phase 3 trials and emerging principles of ovarian tumor biology.

RESULTS

There is no evidence that adding a third cytotoxic agent improves clinical outcomes. However, weekly dose-dense scheduling of paclitaxel appears superior to standard dosing.

CONCLUSION

Primary therapy with carboplatin and paclitaxel remains a well-tolerated standard regimen, including the option of weekly paclitaxel dosing. Data are awaited from completed trials incorporating bevacizumab. Emerging biological paradigms will contribute to individualized treatment options in the future.

Assessment of tumor response as a surrogate endpoint of survival in recurrent/platinum-resistant ovarian carcinoma: a Gynecologic Oncology Group study

PURPOSE

We investigated whether tumor response rate (TRR), disease control rate (DCR), or progression-free survival (PFS) was a valid surrogate for overall survival (OS) in phase II trials of second-line therapies for patients with platinum-resistant ovarian carcinoma (PROC).

METHODS

We retrospectively evaluated data from 11 second-line phase II trials conducted for PROC by the Gynecologic Oncology Group (GOG). TRR included complete response and partial response (CR/PR) and DCR was defined as either tumor response or stable disease (CR/PR+SD). Survival by tumor response was analyzed using a landmark approach. Correlations of OS with TRR, DCR, and PFS were estimated.

RESULTS

Among 407 patients analyzed the TRR was 13.8% (56/407) and DCR was 38.8% (158/407). Median OS was 10.2 months while median PFS was only 2.4 months. Median OS among patients with a best response of CR/PR, SD, and progressive disease (PD) was 13.3, 12.1 and 5.7 months, respectively, showing no difference between CR/PR and SD. From a protocol level, DCR correlated better with OS (Pearson r=0.748; Tau-b r=0.514) compared to TRR (Pearson r=0.564; Tau-b r=0.404). PFS rate at 6 months (Pearson r=0.661; Tau-b r=0.514) also correlated strongly with OS.

CONCLUSIONS

This study demonstrates the limitations of the use of response rate alone in PROC. Clinical benefit, as defined by OS, appeared similar for patients with an objective response and those with SD. The DCR, by including tumor response and SD may have utility as a surrogate endpoint for survival in phase II therapeutic trials in PROC.

Phase II evaluation of pemetrexed in the treatment of recurrent or persistent platinum-resistant ovarian or primary peritoneal carcinoma: a study of the Gynecologic Oncology Group

PURPOSE

To estimate the antitumor activity of pemetrexed in patients with persistent or recurrent platinum-resistant epithelial ovarian or primary peritoneal cancer and to determine the nature and degree of toxicities.

PATIENTS AND METHODS

A phase II trial was conducted by the Gynecologic Oncology Group. Patients must have had cancer that had progressed on platinum-based primary chemotherapy or recurred within 6 months. Pemetrexed at a dose of 900 mg/m(2) was to be administered as an intravenous infusion over 10 minutes every 21 days. Dose delay and adjustment was permitted for toxicity. Treatment was continued until disease progression or unacceptable adverse effects.

RESULTS

From July 6, 2004, to August 23, 2006, 51 patients were entered. A total of 259 cycles (median, four; range one to 19 cycles) of pemetrexed were administered, with 40% of patients receiving six or more cycles. Overall, the treatment was well tolerated. More serious toxicities (grade 3 and 4) included neutropenia in 42%, leukopenia in 25%, anemia in 15%, and constitutional in 15% of patients. No treatment-related deaths were reported. One patient (2%) had a complete and nine patients (19%) had partial responses, with a median duration response of 8.4 months. Seventeen patients (35%) had stable disease for a median of 4.1 months. Eighteen patients (38%) had increasing disease. Three patients (6%) were not assessable. Median progression-free survival was 2.9 months, and overall survival was 11.4 months.

CONCLUSION

Pemetrexed has sufficient activity in the treatment of recurrent platinum-resistant ovarian cancer at the dose and schedule tested to warrant further investigation.

Combination chemotherapy of oxaliplatin and 5-fluorouracil may be an effective regimen for mucinous adenocarcinoma of the ovary: a potential treatment strategy

Resistance of ovarian mucinous adenocarcinoma to standard chemotherapy with paclitaxel and carboplatin is associated with poor prognosis, and an effective treatment is needed. The present study aimed to identify an effective chemotherapy for ovarian mucinous adenocarcinoma. Five human ovarian mucinous adenocarcinoma cell lines (MN-1, OMC-1, RMUG-L, RMUG-S, TU-OM-1) were used in this study. Sensitivity of the cells to the anticancer agents was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and we assessed drug sensitivity by calculating the assay area under the curve for each agent. Protein expression was confirmed by Western blot analysis. We also examined the efficacy of combination chemotherapy on survival in a xenograft model of nude mice. The IC(50) to anticancer agents ranged widely. The assay area under the curve indicated that two of five cell lines (MN-1, TU-OM-1) were sensitive to oxaliplatin, 5-fluorouracil and etoposide, and only one (TU-OM-1) was sensitive to 7-ethyl-10-hydroxycamptothecin, which is an active metabolite of camptothecin. All cell lines were resistant to cisplatin and paclitaxel. The combination of oxaliplatin and 5-fluorouracil resulted in additive or synergistic effects on all cell lines. The combination of oxaliplatin and 5-fluorouracil significantly prolonged survival in a ovarian mucinous adenocarcinoma xenograft model of nude mice. Protein expression levels of the excision repair cross-complementation group 1 were lower in oxaliplatin sensitive cell lines. Exposure to 5-fluorouracil down-regulated cross-complementation group 1 expression in ovarian mucinous adenocarcinoma cells. We conclude that combination chemotherapy consisting of oxaliplatin and 5-fluorouracil was an effective treatment for ovarian mucinous adenocarcinoma and may be a pivotal candidate for a novel treatment strategy.

A phase II study of vorinostat in the treatment of persistent or recurrent epithelial ovarian or primary peritoneal carcinoma: a Gynecologic Oncology Group study

PURPOSE

This multi-institutional phase II trial assessed the activity and toxicity of a new histone deacetylase inhibitor, vorinostat (suberoylanilide hydroxamic acid--SAHA) in patients with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma.

PATIENTS AND METHODS

Women with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma who were platinum-resistant/refractory (progression-free interval <12 months since platinum) were eligible for trial entry if they had measurable disease, a good performance status, and good overall organ function. Women were treated with a 400 mg daily oral dose of vorinostat and continued on treatment until disease progression or unacceptable toxicity. The primary endpoints were progression-free survival (PFS) at 6 months and toxicity. Secondary endpoints were tumor response, duration of PFS and duration of overall survival (OS).

RESULTS

Twenty-seven women were enrolled through the Gynecologic Oncology Group (GOG) on the planned first stage of accrual for this trial and were eligible for analysis. Two women survived progression-free over 6 months, with one having a partial response. Two grade 4 toxicities were reported (one leukopenia and one neutropenia). The most common grade 3 toxicities were constitutional (3/27; 11%) and gastrointestinal (3/27, 11%). Other grade 3 toxicities included neutropenia, metabolic abnormalities, and thrombocytopenia (two patients each, 7%) as well as neurologic complaints and pain (1 patient each; 4%).

CONCLUSION

Vorinostat is well tolerated but had minimal activity as a single agent in unscreened patients with recurrent platinum-refractory ovarian or primary peritoneal carcinoma.

Recurrent epithelial ovarian cancer: pharmacotherapy and novel therapeutics

Epithelial ovarian cancer will strike between 1 - 2% of women in developed countries and, unfortunately, it largely remains a lethal disease due to late-stage at diagnosis and the eventual development of chemotherapy resistance. Ovarian cancer is initially treated with surgical resection and chemotherapy (primarily platinum/taxane combinations) and remission can be attained for the majority of patients. Despite this, most women will recur and require multiple further therapies. The purpose of this paper is to review the existing treatment options, including surgery, traditional chemotherapy as well as upcoming novel and targeted therapies that may one day improve outcomes in this disease.

Oxaliplatin for the treatment of cisplatin-resistant cancer: A systematic review

Oxaliplatin is widely regarded as being active in cisplatin-resistant cancer. We undertook a systematic review of the literature to identify, describe and critique the clinical and pre-clinical evidence for the use of oxaliplatin in patients with "cisplatin-resistant" cancer. We identified 25 pre-clinical cell models of platinum resistance and 24 clinical trials reporting oxaliplatin based salvage therapy for cisplatin-resistant cancer. The pre-clinical data suggests that there is cross-resistance between cisplatin and oxaliplatin in low-level resistance models. In models with high level resistance (>10-fold) there is less cross-resistance between cisplatin and oxaliplatin, which may be a reason why oxaliplatin is thought to be active in cisplatin-resistant cancer. In clinical trials where oxaliplatin has been used as part of salvage therapy for patients who have failed cisplatin or carboplatin combination chemotherapy, there was a much lower response rate in patients with platinum-refractory or resistant cancers compared to platinum-sensitive cancers. This suggests that there may be cross-resistance between cisplatin and oxaliplatin in the clinic. Oxaliplatin as a single agent had a poor response rate in cisplatin refractory and resistant cancer. Oxaliplatin performed better in combination with other agents for the treatment of platinum-resistant/refractory cancer suggesting that the benefit of oxaliplatin may lie in its more favourable toxicity and ability to be combined with other drugs rather than an underlying activity in cisplatin resistance. Oxaliplatin therefore should not be considered broadly active in cisplatin-resistant cancer.

Docetaxel and oxaliplatin in the second-line treatment of platinum-sensitive recurrent ovarian cancer: a phase II study

BACKGROUND

A prospective phase II study was conducted to evaluate the efficacy and toxicity of the combination docetaxel (Taxotere) (DTX) and oxaliplatin (OXA) in ovarian cancer patients recurring after a platinum-free interval (PFI) >12 months.

PATIENTS AND METHODS

DTX, 75 mg/m(2), was administered by 60 min i.v. infusion, followed by OXA, 100 mg/m(2), given by a 2 h i.v., on day 1 every 21 days.

RESULTS

From October 2003 to June 2006, 43 ovarian cancer patients were enrolled. Median PFI was 26 months. All patients were available for response evaluation: 17 complete responses and 12 partial responses were registered, for an overall response rate of 67.4%. The median response duration was 10 months. Stable disease was documented in 11 patients (median duration = 5.5 months). The median time to progression and overall survival were 14 and 28 months. A total of 259 courses were administered. Grade 3-4 leukopenia was documented in 32.5% of the patients, while no case of severe anemia and thrombocytopenia was observed. Grade 3-4 neurotoxicity and grade 2 alopecia were observed in 9.3% and 34.9% of cases, respectively.

CONCLUSION

DTX/OXA combination is an active regimen with a favorable toxicity profile, for treatment of recurrent platinum-sensitive ovarian cancer patients.

Phase II study of irinotecan plus doxorubicin for early recurrent or platinum-refractory ovarian cancer: interim analysis

The aim of this study was to evaluate the efficacy and toxicity of irinotecan and doxorubicin in the treatment of patients with early recurrent or platinum-refractory ovarian cancer. Nineteen woman from five different institutions were treated. Two patients had platinum-refractory cancer, 11 had platinum-resistant disease, and 6 had platinum-sensitive tumors. An intravenous infusion of Irinotecan (50 mg/m(2)) was given on days 1, 8, and 15, while doxorubicin (40 mg/m(2)) was administered as an intravenous bolus on day 3. This treatment schedule was repeated every 4 weeks. Among the 13 patients defined as having platinum-refractory/platinum-resistant disease, 4 patients achieved a clinical response (30.8%, 95% CI: 9.1-61.4), while only one of 6 patients defined as having platinum-sensitive disease achieved a clinical response (16.7%, 95% CI: 0.4-64.1). Leukopenia and neutropenia were the major dose-limiting toxicities. Grade 3 or 4 leukopenia and neutropenia were noted in 24 (48%) and 33 (66%) of the courses, while febrile neutropenia occurred in 2 courses. Five patients (26%) had grade 2 or worse diarrhea during 7 courses. Our data demonstrated that this regimen might be comparable to standard approved agents in patients with early recurrent or platinum refractory ovarian cancer.

A phase I trial of oxaliplatin and topotecan in recurrent ovarian carcinoma

OBJECTIVE

Oxaliplatin and topotecan have demonstrated activity as single agents against recurrent platinum-sensitive and -resistant ovarian cancer, as well as synergy in vitro. This was a dose-finding study of combination therapy with weekly topotecan and alternating-week oxaliplatin in patients with recurrent epithelial ovarian cancer.

METHODS

Eligible patients had a diagnosis of recurrent ovarian or primary peritoneal carcinoma, a performance status of 0-2, and normal bone marrow, renal, and hepatic function. On days 1 and 15 of a 28-day cycle, patients received a fixed dose of oxaliplatin (85 mg/m2) via intravenous infusion. On days 1, 8, and 15, patients received an escalating dose of intravenous topotecan (2.0-4.0 mg/m2). Five dose levels were planned with a minimum cohort of 3 patients at each level.

RESULTS

Thirteen patients were enrolled and received a total of 50 cycles of chemotherapy. The maximum tolerated dose was 85 mg/m2 of oxaliplatin and 3.0 mg/m2 of topotecan, and grade 3 neutropenia was the dose-limiting toxicity. Four of nine (44%) evaluable patients had stable disease or a partial response to the drug combination as assessed by cancer antigen-125 levels.

CONCLUSIONS

A 28-day schedule of oxaliplatin and topotecan is safe and well tolerated. Because of the in vitro synergy observed between topoisomerase I inhibitors and platinum derivatives and the tolerability reported in the current study, this regimen warrants further investigation.

Clinical application of oxaliplatin in epithelial ovarian cancer

Platinum remains the most active drug class in ovarian cancer treatment; however, new single-agent and combination therapies are needed to improve the clinical outcome of ovarian cancer therapies. Oxaliplatin, a third-generation platinum derivative, has shown effective antitumor activity and a favorable toxicity profile in epithelial ovarian cancer. Preclinical evidence of the synergistic cytotoxic effect of oxaliplatin in combination with several other chemotherapeutic agents and clinical evidence of the absence of any dose-limiting hematologic toxicity associated with this agent have made oxaliplatin an attractive compound for combination agent therapy. This article reviews the current status of the clinical application of oxaliplatin alone and in a combination regimen in epithelial ovarian cancer treatment.

Emerging drugs for ovarian cancer

Because most patients presenting with advanced ovarian cancer are not curable by surgery alone, chemotherapy represents an essential component of treatment. The disease may be considered as chemosensitive, as in around three-quarters of patients major (complete) responses are seen to initial treatment with the platinum-containing drugs cisplatin and carboplatin either used alone or in combination with the taxane, paclitaxel. However, only 15-20% of patients experience long-term remission as tumours often become resistant. The probability of achieving a second response depends on the duration of remission after first-line therapy: if this is < 6 months (considered as platinum resistant) second responses are uncommon and usually short-lived; if this is > 6, and especially if > 12 months (platinum sensitive), responses may be seen in about a quarter of patients, to the same drugs as used first line or to drugs such as pegylated liposomal doxorubicin, topotecan and hexamethylmelamine (all three are approved in this setting by the FDA). Gemcitabine, oral etoposide, docetaxel and oxaliplatin also show some activity either in sequential addition to existing approved of first-line therapy (as with gemcitabine) or as second-line therapy. However, there is an urgent unmet clinical need for new drugs capable of prolonging survival either by increasing long-term remission rates and/or duration as first-line treatment or to improve on outcomes of second-line treatment. Strategies currently being exploited in clinical trials include attempts to deliver more killing selectively to tumours (e.g., intraperitoneal administration of cisplatin or radiolabelled monoclonal antibodies), agents designed to target drug resistance mechanisms (e.g., TLK-286 activated by glutathione transferase), agents targeting proteins/receptors shown to be selectively expressed in the disease (e.g., monoclonal antibodies recognising CA-125 or HER1; small molecules targeting HER1 such as gefitinib) and disrupting established tumour vasculature (e.g., 5,6-dimethyl xanthenone 4-acetic acid). At the pre-clinical level, agents being developed to target the phosphatidylinositol 3 kinase/AKT/mTOR pathway, and K-Ras inhibitors, may offer efficacy in the future.

A phase II study of a paclitaxel and oxaliplatin combination in platinum-sensitive recurrent advanced ovarian cancer patients

PURPOSE

A multicentric, phase II study to evaluate the efficacy and safety of the combination paclitaxel and oxaliplatin in patients with platinum-sensitive recurrent ovarian cancer.

PATIENTS AND METHODS

Patients received 175 mg/m(2) paclitaxel (over 3 h) followed by 130 mg/m(2) oxaliplatin (over 2 h) every 21 days for up to nine cycles without hydration or primary granulocyte colony-stimulating factor prophylaxis. Patients had to have an Eastern Cooperative Oncology Group performance status of 0-2 and to have received no more than one prior cisplatin- and/or carboplatin-containing chemotherapy regimen with a platinum-progression-free interval > or =6 months.

RESULTS

Of the 105 patients enrolled and treated, 98 were eligible. An overall response rate of 81% (79 of 98 patients) (95% confidence interval 71% to 88%) was observed according to RECIST criteria (third party reviewed), and 88% (86 of 98) when this was complemented with CA-125 response. With a median follow up of 43.6 months (range 30.2-64.2) the median progression-free survival was 10.2 months (range 0.3-21.4) and the overall survival 32.4 months. Seven hundred and eight cycles were administered (median seven per patient; range one to nine). A total of 67% of patients experienced National Cancer Institute Common Toxicity Criteria grade 3-4 neutropenia, including 8% with concomitant febrile episode, without treatment-related deaths. Ninety-three per cent of patients experienced neuropathy of grade 1 or more, including 25% with cumulative reversible peripheral neuropathy of grade 3-4. Oxaliplatin doses were reduced in 30 patients due to neurotoxicity.

CONCLUSIONS

The oxaliplatin/paclitaxel combination can be administered in an outpatient setting every 3 weeks without specific measures. The high level of activity and its duration observed warrants further evaluation of this combination in pretreated platinum-sensitive advanced ovarian cancer patients.

A6, a urokinase plasminogen activator (uPA)-derived peptide in patients with advanced gynecologic cancer: a phase I trial

OBJECTIVES

The aim of this study was to define the toxicity, maximum feasible dose (MFD), and pharmacokinetics (PK) of A6, a peptide derived from human urokinase plasminogen activator (uPA), in patients with advanced gynecologic cancers, and to explore anti-tumor activity and the effects of A6 on biomarkers of the urokinase system.

METHODS

A6 was administered subcutaneously daily, and doses were escalated in cohorts of three to six subjects. Serial blood specimens were obtained for pharmacokinetics and levels of urokinase plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor-1 (PAI-1).

RESULTS

Sixteen patients were enrolled and eligible for evaluation. No serious drug-related adverse events or dose-limiting toxicity occurred. A6-related toxicities were limited to grades 1 and 2 adverse effects including local injection site reactions. Five patients had stable tumor measurements for at least 4 cycles, one of whom stayed on study for 12 months. One patient had a confirmed cancer antigen (CA)-125 response (decrease in CA-125 of >50%) with stable disease on CT scan after 14 cycles and continues on study. Time to peak plasma level of A6 was 1-2 h. C(max) is proportional to dose. The half-life of A6 was approximately 2 h. Baseline biomarker levels did not predict response and trends over time did not correlate with outcome.

CONCLUSIONS

A6 given daily continuously is well tolerated at all dose levels, without any dose-limiting toxicity. Based on the preliminary activity of A6, a phase II trial is underway in ovarian cancer.

Oxaliplatin plus high-dose leucovorin and 5-fluorouracil (FOLFOX 4) in platinum-resistant and taxane-pretreated ovarian cancer: a phase II study

OBJECTIVE

A prospective phase II study was conducted to evaluate the efficacy and toxicity of oxaliplatin plus 5-fluoruracil (5-FU) and high-dose leucovorin (LV) (FOLFOX-4) in patients with platinum-resistant, taxane-pretreated recurrent ovarian cancer.

PATIENTS AND METHODS

Thirty-eight patients, with a median age of 58 years (range 33-77), were treated with oxaliplatin 85 mg m(-2) as a 2-h infusion on day 1, LV 200 mg m(-2) day(-1) as a 2-h infusion followed by bolus 5-FU 400 mg m(-2) day(-1) and a 22-h infusion of 5-FU 600 mg m(-2) day(-1) for 2 consecutive days. Treatment was repeated every 3 weeks. Patients were evaluated for response every two cycles.

RESULTS

The vast majority of patients had performance status 0 or 1 and 76.3% had > or = 2 metastatic sites. A median number of four cycles per patient (range, 1-8) were administered. Based on an intention-to-treat analysis, 3 patients (7.9%) achieved a complete response (CR) and 8 (21.1%) achieved a partial response (PR), for an overall response rate of 29%. Another 29% of patients had stable disease (SD). The median relapse-free survival was 5.2 months (range 2.5-17), the median time to tumor progression was 4.8 months (range 0.6-19), and the median overall survival was 10.1 months (range 0.2-36). Toxicity was mild to moderate. Grade 3/4 neutropenia and thrombocytopenia occurred in 29% and 21.1% of patients, respectively. Febrile neutropenia was encountered in 3 patients (7.9%), who were successfully treated. Grade 3/4 neurotoxicity developed in 15.8% of patients; neurotoxicity gradually declined after treatment discontinuation. Alopecia, nausea-vomiting, diarrhea, mucositis, and asthenia were not a serious problem. There were no treatment-related deaths.

CONCLUSION

The combination of oxaliplatin and 5-FU/LV (FOLFOX-4) appears to be an effective regimen with a good toxicity profile for the treatment of platinum-resistant, taxane-pretreated ovarian cancer.

Phase II trial of Oxaliplatin and 5-Fluorouracil/Leucovorin combination in epithelial ovarian carcinoma relapsing within 2 years of platinum-based therapy

OBJECTIVE

To evaluate the efficacy and toxicity of Oxaliplatin and 5-Fluorouracil (5-FU)/Leucovorin (LV) combination in ovarian cancer relapsing within 2 years of prior platinum-based chemotherapy in a phase II trial.

METHODS

Eligible patients had at least one prior platinum-based chemotherapy regimen, elevated CA-125 > or = 60 IU/l, radiological evidence of disease progression and adequate hepatic, renal and bone marrow function. Patients with raised CA-125 levels alone as marker of disease relapse were not eligible. Oxaliplatin (85 mg/m(2)) was given on day 1, and 5-Fluorouracil (370 mg/m(2)) and Leucovorin (30 mg) was given on days 1 and 8 of a 14-day cycle.

RESULTS

Twenty-seven patients were enrolled. The median age was 57 years (range 42-74 years). The median platinum-free interval (PFI) was 5 months (range 0-17 months) with only 30% of patients being platinum sensitive (PFI > 6 months). Six patients (22%) had two prior regimens of chemotherapy. A total of 191 cycles were administered (median 7; range 2-12). All patients were evaluable for toxicity. The following grade 3/4 toxicities were noted: anemia 4%; neutropenia 15%; thrombocytopenia 11%; neurotoxicity 8%; lethargy 4%; diarrhea 4%; hypokalemia 11%; hypomagnesemia 11%. Among 27 enrolled patients, 20 patients were evaluable for response by WHO criteria and 25 patients were evaluable by Rustin's CA-125 criteria. The overall response rate (RR) by WHO criteria was 30% (95% CI: 15- 52) [three complete responses (CRs) and three partial responses (PRs)]. The CA-125 response rate was 56% (95% CI: 37-73). Significantly, a 25% (95% CI: 9-53) radiological and a 50% (95% CI: 28-72) CA-125 response rate were noted in platinum resistant patients (PFI < 6 months). The median response duration was 4 months (range 3-12) and the median overall survival was 10 months.

CONCLUSION

Oxaliplatin and 5-Fluorouracil/Leucovorin combination has a good safety profile and is active in platinum-pretreated advanced epithelial ovarian cancer.