© 2000 AlphaMed Press
Highlights in Ovarian CancerMassachusetts General Hospital, Boston, Massachusetts, USA Correspondence: Michael V. Seiden, M.D., Ph.D., Massachusetts General Hospital, Cox 640, 100 Blossom Street, Boston, Massachusetts 02114, USA. Telephone: 617-724-3123; Fax: 617-724-3166; e-mail: Seiden.Michael{at}MGH.Harvard.edu
The ovarian cancer presentations at the 2000 ASCO meeting did not yield any major paradigm shifts in the treatment of women with epithelial ovarian cancer. Emphasis at this year's meeting focused on the potential incorporation of drugs such as topotecan, oxaliplatin, doxil, and gemcitabine into the initial treatment strategies of women with advanced ovarian cancer. These studies included the introduction of several active and tolerable regimens that are potentially worthy of direct comparison to the carboplatin and paclitaxel combination. In the woman with recurrent or persistent ovarian cancer there was a greater focus on phase III studies directly comparing various chemotherapy strategies in the treatment of women with recurrent disease. This included the comparisons of single-versus two-drug salvage regimens, alternate salvage schedules, and direct comparison of agents active in taxane- and platinum-resistant disease. Finally, several early studies of novel non-chemotherapeutic strategies were presented. Key Words. Ovarian cancer • Treatment • ASCO
Randomized Trial of Paclitaxel and Carboplatin versus a Control Arm of Carboplatin or CAP (Cyclophosphamide, Doxorubicin, and Cisplatin): The Third International Collaborative Ovarian Neoplasm Study (ICON 3). N Colombo, on behalf of the ICON Collaborators (ABSTRACT 1500).
Study Design and Results
Although not fully mature, the median follow-up is now 29 months, and the analysis of this trial currently supports the conclusions made during last year's ASCO meeting, namely that control therapy gives equivalent overall survival and progression-free survival (PFS) as carboplatin and paclitaxel. Table 1
Commentary The results from this very large multinational study continue to stand in direct contrast with the results of Gynecologic Oncology Group (GOG) 111 [2] and the Intergroup studies [3] that represent similar, albeit not identical, studies performed in the United States, Canada, and Europe, and it seems unlikely that further follow-up will change the conclusions of any of these trials. The reason for the discrepancies between ICON 3 and its well-known predecessor trials is unclear although the unusual method of assigning control arms, the inclusion of low- and high-stage patients, the potential for taxol contamination in the control arms, and the unexplained good median survival of 36 months in the control arm are all topics that give cause for caution in accepting these results. The question will require further observation as the trial matures over the next two years. While the ICON 3 trial does not support the inclusion of paclitaxel into the upfront treatment of epithelial ovarian cancer, on balance, the total body of clinical trial evidence still supports paclitaxel with carboplatin as the standard first-line regimen in women with ovarian cancer who require systemic therapy. Nevertheless, it is probably reasonable to consider that paclitaxel and carboplatin may not be vastly superior to treatment with carboplatin followed subsequently by paclitaxel. Indeed, similar conclusions have been suggested by GOG 132 [4] that suggested cisplatin followed by paclitaxel was equivalent to cisplatin and paclitaxel. Indeed, ICON 3, GOG 132, and several of the second-line studies discussed below suggest that doublet and triplet therapy may not be superior to sequential single-agent therapy. Multicenter Phase II/III Trial of Oxaliplatin plus Cyclophosphamide versus Cisplatin plus Cyclophosphamide in Advanced Chemonaïve Ovarian Cancer Patients: Final Results. JL Misset, P Vennin, P Chollet, J Pouillart, D Frober, M Castera, M Fabr, E Cortesei, E Gamelin, G Dupont-Andre, A Laadem, J Otero (ABSTRACT 1502).
Study Design and Results
The trial enrolled 177 women between 1992 and early 1996 with stage II, III, and IV ovarian cancer, with 85 evaluable patients in the oxaliplatin arm and 92 patients in the cisplatin arm. Compared to the cisplatin arm, the oxaliplatin arm had fewer dose delays, less hematologic toxicity and fewer withdrawals from the treatment plan. Specifically 18% of the woman assigned to cisplatin were withdrawn from treatment for toxicity concerns compared to only 2% of patients on the oxaliplatin arm. Table 3
Although not sufficiently large to generate meaningful survival comparisons, oxaliplatin was clearly active with a median overall survival of 36 months for the oxaliplatin arm compared to 25 months for the cisplatin arm (not significant); both treatments had an identical PFS of 13 months.
Commentary
A Phase I, Dose-Finding Study of Carboplatin, Paclitaxel, and Liposomal Doxorubicin in Advanced Epithelial Ovarian Carcinoma. (EOC). D Gibbs, L Pyle, M Allen, A Webb, S Johnston, ME Gore (ABSTRACT 1539). A Phase II Study of Docetaxel and Carboplatin in the Treatment of Suboptimally Debulked Stage III and Stage IV Ovarian Carcinoma. JA Ruiz, I Smith, A Wertheim, A Troxel, P Rosenman, KH Antman, A Tiersten (ABSTRACT 1593). Effective First Line Therapy of Ovarian Cancer with Cisplatin and Prolonged Topotecan Infusion a NYGOG/ ECOG Study. J Speyer, H Hochster, S Wadler, C Runowicz, J Michalak, J Mandeli, A Fields, P Anderson, J Sorich, H Wasserstrom, R Wallach, F Muggia (ABSTRACT1503). Paclitaxel, Topotecan, and Cisplatin Combination Chemotherapy in Advanced Ovarian Cancers. Results of a Pilot Study. D Coeffic, EC Antoine, MA Rocher, JP Spano, JP Grapin, I Lorenzi, E Mularoni, G Auclerc, D Nizri, M Delgado, D Khayat (ABSTRACT1601). The ASCO 2000 had numerous posters exploring the efficacy and toxicity of novel doublets such as gemcitabine with cisplatin, docetaxel with cisplatin, and topotecan with carboplatin, as well as novel triplets incorporating either topotecan or doxil into the taxol and platinum backbone. All of these regimens demonstrate efficacy and acceptable toxicity if dosed appropriately. Further definition of the activity of these doublets and triplet regimens will require randomized trials comparing the novel regimen to carboplatin with paclitaxel.
This year's ASCO presentations included three relatively large randomized studies evaluating treatment strategies for recurrent disease. Trials evaluating three different and important questions were asked. First, is there superiority for one salvage regimen over another (e.g., doxil versus topotecan) in terms of survival, response, or toxicity? Second, is there superiority of schedules of the same drug (e.g., paclitaxel)? Third, is there superiority of doublet salvage therapy compared to treatment with a single drug (e.g., epirubicin/paclitaxel versus paclitaxel alone)? All three of these trials are important in beginning to address central issues in the management of women receiving palliative care for their recurrent disease. Interim Analysis of a Phase II Randomized Trial of Doxil/Caelyx versus Topotecan in the Treatment of Patients with Relapsed Ovarian Cancer. A Gordon, J Fleagle, D Guthrie, D Parkin, M Gore, A Lacave, D Mutch (ABSTRACT1504).
Study Design and Results
Review of the patient population reveals good balance between the known prognostic factors. Response rates, time to progression as well as overall survival are equivalent in the two groups (Table 4
Commentary At the time of final analysis, this will be the largest randomized trial of patients with relapsed ovarian cancer. The results confirm that both agents are active in recurrent ovarian cancer including platinum-resistant ovarian cancer. Topotecan, a myelotoxic drug, frequently requires growth-factor support, while doxil is toxic to both skin and oral mucosa. doxil's simple administration schedule and potentially superior safety profile make it a strong candidate for second-line therapy in the treatment of women with recurrent disease. Several additional pieces of information are needed before making firm conclusions, including the review of the quality-of-life data collected in this trial, final analysis of the entire patient data set for response and toxicity, and further data on the potential survival advantage of doxil in platinum-sensitive patients. Finally, two further points must be considered, but unfortunately will not be answered by this study. First, the dose of both doxil and topotecan used in clinical practice is now typically delivered at about 80% of the dose intensity delivered in this study and hence, the toxicities reported for both drugs in this trial are higher than those seen in typical practice. Also if one assumes that many patients with recurrent ovarian cancer will receive both doxil and topotecan as part of their salvage therapies, it may be logical to give the most myelotoxic regimen, (i.e., topotecan) first followed by doxil. Finally, response rates of 7% to 12% in platinum-resistant disease are far from satisfactory and highlight the need for new agents in this difficult patient population. An Updated Analysis of a Randomized Study of Single Agent Paclitaxel Given Weekly versus Every Three Weeks to Patients with Ovarian Cancer Treated with Prior Platinum Therapy. H Andersson, K Bowman, M Ridderheim, P Rosenberg, B Sorbe, U Puistola, G Horvath (ABSTRACT1505).
Study Design and Results To minimize the potential effect of dose intensity, patients on the weekly schedule started on 67 mg/m2/week while patients on the q three-week schedule were treated with 200 mg/m2/3 week, which calculates to identical dose intensity. Depending on toxicity, patients could be either dose de-escalated or dose escalated. The primary endpoint was overall response rate, and patients were allowed only one prior platinum-containing regimen. Patients had not received paclitaxel prior to study entry. Two hundred and six eligible patients were evaluated with approximately 50% of patients defined as platinum-resistant. Patients treated on the weekly schedule achieved a dose intensity of 77 mg/m2/week of paclitaxel, while those on every three-week paclitaxel had a median-dose intensity of 72 mg/m2/week. The three-week paclitaxel schedule had significantly more leukopenia, neutropenia, and alopecia while there was more nail toxicity with weekly taxol. Response rates were essentially identical at 37% with a very similar time to progression.
Commentary Randomized Trial Comparing Paclitaxel + Epirubicin Versus Paclitaxel as Second-Line Therapy for Advanced Ovarian Cancer Patients in Early Progression after Platinum-Based Therapy. V Torri, I Floriani, A Tinazzi, PF Conte, A Ravaioli, MG Cantù, R Rossi, L Grassi, G Parma, N Colombo, M Negri (ABSTRACT 1506).
Study Design and Results This was a large study with 227 women who were enrolled a mean of three months from the completion of primary platinum-based therapy. While approximately 50% of the patients had received only single-agent carboplatin, about 25% of woman had had a previous anthracycline with their initial therapy. All women were paclitaxel-naïve. Paclitaxel was delivered at 175 mg/m2 every three weeks in both arms, while the women assigned to the doublet arm also received epirubicin at 80 mg/m2. The women received four cycles of therapy. Those demonstrating stable or responding disease then received two additional cycles, assuming toxicity was acceptable. Paclitaxel single-agent therapy was completed in 70% of patients, although 11% of patients required dose reduction or dose delay. Only 59% of patients completed the doublet regimen as scheduled. Grade 3 or 4 neutropenia was much higher in doublet arm (41%) than in the single-agent arm (18%). Response rates were statistically identical in the two arms with no difference in progression-free or overall survival. As suggested in earlier studies, patients with platinum-resistant ovarian cancer carry a poor prognosis with median survival of only 12 months from study entry.
Commentary
Mitoxantrone Plus Paclitaxel: A Highly Active Salvage Regimen for Heavily Pretreated Ovarian Cancer. M Janat, CM Kurbacher, D Rein, IA Cree, P Mallmann, PE Andreotti, HW Bruckner (ABSTRACT 1518).
Study Design and Results The mitoxantrone and paclitaxel study explored two different schedules of mitoxantrone and paclitaxel in 33 heavily treated patients of whom 28 were regarded to be platinum-refractory. The regimen was myelotoxic and approximately half of the patients required G-CSF support. An overall response rate was 69% with 12 complete remissions. PFS was 9.5 months with an encouraging overall survival of 20.5 months. This response is more than double those seen with many other salvage regimens using similar drugs such as doxorubicin with paclitaxel or epirubicin and paclitaxel. The reasons for the superior response are not clear and the trial will require confirmation in other clinical centers.
Phase II Study of Irofulven (MGI-114) in Platinum- and Paclitaxel-Resistant Epithelial Ovarian Cancer. SJ Vukelja, AN Gordon, JJ Muscato, KC Hancock, G Weems, SL Smith, JR MacDonald, L Herdrich (ABSTRACT 1578).
Study Design and Results
Commentary A Phase I Trial of AD p53 for Ovarian Cancer Patients: Correlation with p53 and Anti-Adenovirus AB Status. JK Wolf, D Bodurka-Bevers, J Gano, MT Deavers, C Levenback, L Ramondetta, P Ramirez, D Fightmaster, DM Gershenson (ABSTRACT 1510). Phase I Trial of Intraperitoneal ONYX-015 Adenovirus in Patients with Recurrent Ovarian Cancer. PA Vase, M Seiden, V O'Neill, S Campos, S Johnston, J Davis, D Kin, SB Aye, LN Schulman (ABSTRACT 1512).
Study Design and Results Both studies evaluated the toxicities associated with intraperitoneal delivery of adenovirus over five sequential days. Dose-limiting toxicities in both studies included fatigue, fever, and abdominal pain (particularly with the Onyx-015 virus). Many patients on the Onyx-015 trial had symptoms consistent with a viral syndrome suggesting viral replication. One PR was seen in the p53 adenovirus trial. A second patient had stable disease and is continuing on her fourteenth cycle of therapy. No responses were seen in the 16 patients treated with Onyx-015, although two patients defined as having platinum-resistant ovarian cancer at the time of trial enrollment responded to subsequent carboplatin after Onyx-015 administration. The appropriate daily dose of the replication incompetent p53 adenovirus is unclear but may be 3 x 1012 pfu, while the dose-limiting toxicity for the replication impaired Onyx-015 virus was between 1 x 1010 pfu and 1 x 1011 pfu daily dose.
Commentary
ASCO 2000 serves to further explore the uses of drugs such as topotecan, oxaliplatin, gemcitabine, doxil, and paclitaxel. Unfortunately, there was little to suggest that these drugs will dramatically improve survival of women with ovarian cancer over and above current standards, thus emphasizing the need to continue to incorporate new cytotoxics and novel biologic agents into the treatment scheme for these women. Fortunately, a very large number of new agents are now in phase I clinical trial and have or will enter phase II clinical trials in ovarian cancer within the next two years. Hopefully ASCO 2001 will provide important information on how these compounds may be used to positively impact the lives of women with ovarian cancer.
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