Comparison of the efficacy between topotecan- and belotecan-, a new camptothecin analog, based chemotherapies for recurrent epithelial ovarian cancer: a single institutional experience

Synergism of AZD6738, an ATR Inhibitor, in Combination with Belotecan, a Camptothecin Analogue, in Chemotherapy-Resistant Ovarian Cancer

Epithelial ovarian cancer remains the leading cause of mortality among all gynecologic malignancies owing to recurrence and ultimate development of chemotherapy resistance in the majority of patients. In the chemotherapy-resistant ovarian cancer preclinical model, we investigated whether AZD6738 (an ataxia telangiectasia and Rad3-related (ATR) inhibitor) could synergize with belotecan (a camptothecin analog and topoisomerase I inhibitor). In vitro, both chemotherapy-resistant and chemotherapy-sensitive ovarian cancer cell lines showed synergistic anti-proliferative activity with a combination treatment of belotecan and AZD6738. The combination also demonstrated synergistic tumor inhibition in mice with a chemotherapy-resistant cell line xenograft. Mechanistically, belotecan, a DNA-damaging agent, increased phospho-ATR (pATR) and phospho-Chk1 (pChk1) in consecutive order, indicating the activation of the DNA repair system. This consequently induced G2/M arrest in the cell cycle analysis. However, when AZD6738 was added to belotecan, pATR and pChk1 induced by belotecan alone were suppressed again. A cell cycle analysis in betotecan showed a sub-G1 increase as well as a G2/M decrease, representing the release of G2/M arrest and the induction of apoptosis. In ascites-derived primary cancer cells from both chemotherapy-sensitive and -resistant ovarian cancer patients, this combination was also synergistic, providing further support for our hypothesis. The combined administration of ATR inhibitor and belotecan proved to be synergistic in our preclinical model. This combination warrants further investigation in a clinical trial, with a particular aim of overcoming chemotherapy resistance in ovarian cancer.

Efficacy of cisplatin combined with topotecan in patients with advanced or recurrent ovarian cancer as second- or higher-line palliative chemotherapy

The aim of this study was to evaluate the outcomes of patients with advanced or recurrent ovarian cancer treated with cisplatin combined with topotecan as second- or higher-line palliative chemotherapy.We retrospectively reviewed the medical records of patients with advanced or recurrent ovarian cancer, who were treated with cisplatin (50 mg/m on day 1) and topotecan (0.75 mg/m on days 1-3). Treatment response, progression-free survival (PFS) and overall survival (OS) were analyzed, and laboratory data were reviewed to evaluate toxicities.Thirty one patients were treated with cisplatin and topotecan. The objective response rate (ORR) was 22.6%, and the disease control rate (DCR) was 61.3%. The median PFS was 3.7 months (95% confidence interval [CI], 2.3-5.2 months) and the median OS was 44.5 months (95% CI, 35.5-53.5 months). The ORR (33.3% vs. 0%; P = .012) was significantly better in the platinum-sensitive group compared to the platinum-resistant group. The median PFS was significantly longer in the platinum-sensitive group compared to the platinum-resistant group (7.7 vs 2.5 months; P < .001), and the median OS was also significantly longer in the platinum-sensitive group (46.6 vs 19.3 months; P < .001). Almost all of the patients reported some degree of hematological toxicity. A high rate of grade 3-4 neutropenia (87.1%) was observed. Grade 3-4 thrombocytopenia (41.9%) and febrile neutropenia (19.4%) were also seen.The results showed that cisplatin combined with topotecan, as second- or higher-line palliative chemotherapy for patients with advanced or recurrent ovarian cancer, might be effective, especially in the platinum-sensitive group. However, attention should be paid to the high hematological toxicity associated with this drug combination.

Lesser Toxicities of Belotecan in Patients with Small Cell Lung Cancer: A Retrospective Single-Center Study of Camptothecin Analogs

Purpose. Topotecan and belotecan are camptothecin derivatives that are used to treat small cell lung cancer (SCLC). This study compared the toxicities and efficacies of belotecan and topotecan monotherapies in patients with SCLC. Methods. We retrospectively reviewed data from 94 patients with SCLC (with or without prior chemotherapy) who were treated using belotecan monotherapy (n = 59, 188 cycles) or topotecan monotherapy (n = 35, 65 cycles) between September 2003 and December 2011. Results. Thrombocytopenia occurred during 42% and 61.5% of the belotecan and topotecan cycles, respectively (p = 0.007). Significant differences between belotecan and topotecan were also observed for grade 4/5 lung infection (3.2% versus 10.8%, resp.; p = 0.003), all-grade headache (3.2% versus 10.8%, resp.; p = 0.017), and grade 4/5 increased liver enzymes (0.5% versus 4.6%, resp.; p = 0.023). The median TTPDs, CSSs, and OSs were 14 months and 11.6 months (p = 0.646), 10 months and 7 months (p = 0.179), and 34.5 months and 21.4 months (p = 0.914) after belotecan and topotecan monotherapy, respectively. Conclusions. Belotecan monotherapy may be safer than topotecan monotherapy in SCLC patients. And in terms of efficacy, belotecan could be comparable to topotecan monotherapy.

Durable response after just one cycle of belotecan-based chemotherapy in a patient with relapsed primary peritoneal serous carcinoma

The efficacy of second-line chemotherapy for relapsed primary peritoneal serous carcinoma has been numerously reported, but reports on durable response after second-line therapy have been rare. We report the case of a 66-year-old woman with relapsed primary peritoneal serous carcinoma who showed durable response after just one cycle of second-line belotecan-based therapy. The response might be a complete pathologic remission. Considering the fact that our patient suffered from neutropenic sepsis during her treatment, we concluded that belotecan-based chemotherapy could be a good option for second-line chemotherapy in some selected patients, so patient selection should be carefully performed due to the toxicity of belotecan.

Combination therapy of cilengitide with belotecan against experimental glioblastoma

The prognosis of patients diagnosed with glioblastoma remains dismal in spite of the current concomitant chemoradiotherapy with temozolomide. In particular, the resistance to temozolomide appears to be the greatest obstacle to the treatment of glioblastoma. In the present study, we evaluated in vitro and in vivo the antitumor effects of combination therapy of cilengitide with belotecan, a camptothecin derivate, to treat experimental glioblastoma. The therapeutic effects of the drugs on the U87MG and U251MG human glioblastoma cell lines were assessed using in vitro cell viability and apoptosis assays. The combination treatment group with cilengitide and belotecan enhanced the cytotoxic effects to the glioblastoma cell lines and increased the apoptosis of the tumor cells compared to monotherapy with either drug alone in vitro. Nude mice with established U87MG glioblastoma were assigned to the following four groups: control, cilengitide, belotecan and combination treatment. The volume of tumors and length of survival were also measured. Animals in the combination therapy group demonstrated a significant reduction of tumor volume and an increase in survival (p < 0.05). Immunohistochemistry revealed a decrease in angiogenesis by cilengitide and an increase in apoptosis by cilengitide and belotecan in vivo. The combination therapy of cilengitide with belotecan presented more cytotoxic effects compared to the monotherapy of either drug in vitro and in vivo. This combination protocol may serve as an alternative treatment option for glioblastoma.

Paradoxical expression of AHCYL1 affecting ovarian carcinogenesis between chickens and women

We investigated S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1) gene expression in human epithelial ovarian cancer (EOC) using the chicken, which is the most relevant animal model. Ovarian cancer was detected in 10 of 136 laying hens (7.4%). Results of the present study indicated that AHCYL1 mRNA and protein are most abundant in the glandular epithelium of adenocarcinoma of cancerous, but not normal, ovaries of hens. In addition, bisulfite sequencing to examine methylation patterns in the promoter region of the AHCYL1 gene revealed that 30-38% of the three CpG sites were demethylated in ovarian cancer cells as compared with normal ovarian cells. Furthermore, in human ovarian cancer cells such as OVCAR-3, AHCYL1 protein was predominantly in the nucleus and had a similar expression pattern to that in chicken ovarian cancer cells. Thereafter, we examined the prognostic value of AHCYL1 expression in patients with EOC using multivariate linear logistic regression and Cox's proportional hazard analyses. In 109 human patients with EOC, 14 (12.8%), 41 (37.6%) and 54 (49.6%) patients showed weak, moderate and strong expression of AHCYL1 protein, respectively. However, intermediate or high expression of AHCYL1 protein was a favorable factor for overall responses (adjusted odds ratio, 7.23; 95% confidence interval [CI], 1.36-38.39), and for progression-free survival (adjusted hazard ratio, 0.20; 95% CI, 0.07-0.55). From these results, we conclude that AHCYL1 expression is associated with ovarian carcinogenesis as an oncogene in chickens, whereas it plays the role of tumor suppressor in human EOC, suggesting a paradoxical function of AHCYL1 in ovarian carcinogenesis.

Major clinical research advances in gynecologic cancer in 2010

This review summarizes 11 major clinical research advances in gynecologic oncology in 2010. For ovarian cancer, bevacizumab as a leading molecular targeted agent, pegylated liposomal doxorubicin in recurrent disease, the role of neoadjuvant chemotherapy in an advanced setting, an effective screening method, and ARID1A mutations as a clue to the origin of clear cell carcinoma are mentioned. For cervical cancer, confirmation of the efficacy and the introduction of a self collection method of the human papillomavirus (HPV) test, and the association between the HPV vaccine and miscarriage are examined. For endometrial cancer, the superiority of laparoscopy in staging operation, the role of vaginal brachytherapy in an adjuvant setting, and the effect of para-aortic lymph node dissection are reviewed. In addition, the trend of geriatric oncology and chemotherapy in carcinosarcomas is also assessed.

Phase II study of belotecan, a camptothecin analogue, in combination with carboplatin for the treatment of recurrent ovarian cancer

BACKGROUND

Belotecan (CKD602; Camtobell, Chong Keun Dang Corp., Seoul, Korea) is a recently developed camptothecin derivative with antitumor properties. This phase II study was designed to evaluate the toxicity and efficacy of belotecan combined with carboplatin in patients with recurrent epithelial ovarian cancer (EOC).

METHODS

Thirty-eight patients with recurrent EOC were treated with belotecan 0.3 mg/m(2) /day (days 1-5) and carboplatin AUC 5 (day 5) every 3 weeks for 6 cycles. The primary objective was to determine the response rate as defined by Response Evaluation Criteria in Solid Tumors and CA-125 response. Other end points included toxicities and progression-free survival (PFS).

RESULTS

All 38 patients were assessed for toxicity, and 35 patients were assessed for response. The overall response rate was 57.1%; there were 7 complete responses (20.0%), 13 partial responses (37.1%), 6 patients with stable disease (17.1%), and 9 patients with progressive disease (25.7%). Grades 3 and 4 hematologic toxicities included neutropenia (28.8%), thrombocytopenia (19.8%), and anemia (14.4%), and there were 2 episodes of febrile neutropenia. Median PFS was 7 months, with a median follow-up of 12 months.

CONCLUSIONS

The newly developed topoisomerase I inhibitor belotecan (CKD-602) combined with carboplatin is a well-tolerated regimen with activity in recurrent EOC. Further testing of this regimen is warranted to further characterize efficacy and indications for use.