Pilot Phase 2 Trial of 4 Months of Maintenance Pegylated Liposomal Doxorubicin in Patients with Advanced Ovarian Cancer after Complete Response to Platinum and Paclitaxel-Based Chemotherapy

Emerging serine-threonine kinase inhibitors for treating ovarian cancer

Introduction: Ovarian cancer is the leading cause of gynecologic cancer death, owing to high rates of incurable, recurrent disease after initial treatment. Serine threonine kinases (STKs) have been proposed as potential therapeutic targets in ovarian cancer because of their role in the initiation and progression of cancers. Experience in non-ovarian cancers suggests that STK inhibitors are active against tumors with specific molecular alterations.Areas covered: This review discusses STK inhibitors in active development in phase II/III clinical trials for ovarian cancer. PubMed and ClinicalTrials.gov were systematically searched to identify STK inhibitor trials for ovarian cancer; active development was confirmed via Pharmaprojects. Available data regarding the efficacy and safety of these compounds are explored.Expert opinion: STK inhibitors currently in development have modest activity as single agents and are unlikely to achieve approval as monotherapy for unselected ovarian cancer patients. Combination trials of STK inhibitors with chemotherapy and/or targeted therapies have suggested an acceptable efficacy/toxicity ratio for certain combinations but confirmatory studies are needed. Carefully designed trials, especially those including somatic molecular analysis, may help identify the subsets of patients most likely to benefit from these therapeutic strategies and determine the role of STK inhibitors in the evolving landscape of precision oncology.

Efficacy of pegylated liposomal doxorubicin maintenance therapy in platinum-sensitive recurrent epithelial ovarian cancer: a retrospective study

OBJECTIVE

To examine the effectiveness of pegylated liposomal doxorubicin (PLD) maintenance therapy (intravenous administration at dose 40 mg/m² on day 1, repeated every 4 weeks) after first-line salvage chemotherapy for platinum-sensitive recurrent epithelial ovarian cancer.

METHODS

This retrospective cohort study examined women with a first recurrence of platinum-sensitive epithelial ovarian cancer diagnosed between 2005 and 2015. Eligible cases had PLD maintenance following the first-line salvage chemotherapy (n = 28). Outcomes of interest included adverse events related to PLD maintenance therapy and survival outcome after the first recurrence.

RESULTS

The median number of PLD maintenance cycles was 7.5 (range 2-26), and 11 (40%) women received ≥ 12 cycles. The median cumulative dose of PLD was 432.5 mg/m² (range 120-1200 mg/m²). No women developed cardiotoxicity or secondary malignancies. There were 16 (57%) women who developed any grade of adverse events, including 3 (11%) women who developed grade 3 adverse events. There were no grade 4 adverse events. The most common adverse event was mucositis (n = 7, 25%). Dose reduction due to adverse events occurred in 14 (50%) women including 3 (11%) women with discontinuation due to toxicity. Median progression-free survival and overall survival after the initiation of PLD maintenance was 14.5 months (2-year rate 21.1%) and 51.2 months (5-year rate 43.4%), respectively.

CONCLUSION

Our study suggests that PLD maintenance therapy for platinum-sensitive recurrent ovarian cancer is relatively well tolerated with the use of dose reduction to manage toxicity. Our study suggests that PLD maintenance therapy may be effective for women with platinum-sensitive recurrent epithelial ovarian cancer.

Clinical utility of CA-125 for maintenance therapy in the treatment of advanced stage ovarian carcinoma

Maintenance therapy has been extensively studied to discern any prospective therapeutic advantage in the treatment of advanced stage ovarian carcinoma. The CA-125 assay may have prognostic benefit in determining whether this treatment regimen is appropriate for ovarian carcinoma patients who achieve a complete response to first-line therapy. We retrospectively documented the CA-125 levels of 2 advanced ovarian cancer patient groups who exhibited a clinically defined complete response to their primary induction therapy. Patients were then treated with a paclitaxel-based maintenance therapy regimen. The first group (group A; n = 13 patients) received 3 cycles of single-agent paclitaxel maintenance therapy, and the second group (group B; n = 13 patients) received 12 cycles of single-agent paclitaxel maintenance therapy. The premaintenance therapy CA-125 serum levels (<10 or > or =10 U/mL) of the 2 treatment groups were then retrospectively evaluated in an intragroup analysis to discern any relationship with progression-free survival (PFS) and overall survival. There was a statistically significantly relationship between the CA-125 levels (<10 U/mL) premaintenance therapy and PFS. The patients who had the lowest CA-125 levels exhibited the most favorable PFS results. Despite the limited sample size and nonrandomized nature of this study, these results are provocative and suggest that advanced ovarian cancer patients who achieve an excellent response to primary platinum-based chemotherapy with a CA-125 serum level less than 10 U/mL may be more amenable to the benefits of paclitaxel maintenance therapy.

Are three additional cycles of chemotherapy useful in patients with advanced-stage epithelial ovarian cancer after a complete response to six cycles of intravenous adjuvant paclitaxel and carboplatin?

Background

To evaluate the efficacy of three additional cycles of chemotherapy in patients with the International Federation of Gynecology and Obstetrics Stage III or IV, who achieved a complete response after six cycles of intravenous adjuvant paclitaxel/carboplatin after surgery.

Methods

The clinical data of 94 patients with complete response after six cycles of adjuvant paclitaxel/carboplatin after surgery between January 1997 and March 2007 were reviewed retrospectively. Three additional cycles using the same chemotherapy were administered to 57 patients as consolidation chemotherapy (Group 1). Thirty-seven patients without the additional cycles served as controls (Group 2). Disease-free survival (DFS) and overall survival (OS) were evaluated using the Kaplan–Meier method with the log-rank test. The importance of consolidation chemotherapy as a prognostic factor affecting survival was examined using the Cox's proportional hazard analysis. The incidence of chemotherapy-induced hematological toxicities was compared between the two groups using chi-square test.

Results

Median DFS and mean OS were not significantly different between the two groups (15 versus 22 months, P = 0.703; 69 versus 73 months, P = 0.891, respectively). Consolidation chemotherapy was not a prognostic factor of survival although optimal debulking surgery and lower value of serum CA-125 levels after six cycles of the chemotherapy were prognostic factors improving DFS (P < 0.01). Grade 3 or 4 leukopenia was more common in patients treated with consolidation chemotherapy than in those not treated (50.9 versus 21.6%, P = 0.004).

Conclusion

Consolidation chemotherapy using paclitaxel/carboplatin may be inefficient and relatively toxic to advanced-stage epithelial ovarian cancer patients with complete response to six cycles of the same chemotherapy after surgery.

Improved Survival with Single-Agent Paclitaxel Consolidation/Maintenance Therapy in Advanced Ovarian Carcinoma

OBJECTIVES

Consolidation/maintenance therapy in the standard management of ovarian cancer remains controversial, primarily due to the unknown impact of this strategy on overall survival.

METHODS

We examined the survival of a previously reported patient population consecutively treated with either 3 cycles (group A; n = 13 patients) or 12 cycles (group B; n = 13) of single-agent paclitaxel consolidation following 6 cycles of primary induction chemotherapy comprising 6 cycles of carboplatin (AUC = 5), paclitaxel (175 mg/m(2)) and gemcitabine (800 mg/m(2)).

RESULTS

There were no differences in the 2 patient populations regarding known relevant prognostic factors (age, stage, tumor grade). The median progression-free survival was 11 months for group A and 24 months for group B (p = 0.0062). The median overall survival in group A was 38 months and was not reached in group B (p = 0.0019). Current follow-up for these 2 patient groups exceeds 43 months.

CONCLUSION

We recognize the important limitations of this study, particularly its sample size and nonrandomized nature. However, these data provide support for the conclusion that paclitaxel 'maintenance/consolidation' therapy may favorably impact overall and progression-free survival in advanced ovarian cancer patients who achieve an excellent response to primary platinum-based chemotherapy.