Cyclosporin enhancement of cisplatin chemotherapy in patients with refractory gynecologic cancer. A Gynecologic Oncology Group Study

Computational Drug Repositioning Identifies Potentially Active Therapies for Chordoma

BACKGROUND

Chordomas are aggressive bone tumors that often recur despite maximal resection and adjuvant radiation. To date there are no Food and Drug Administration (FDA)-approved chemotherapies. Computational drug repositioning is an expanding approach to identify pharmacotherapies for clinical trials.

OBJECTIVE

To identify FDA-approved compounds for repurposing in chordoma.

METHODS

Previously identified highly differentially expressed genes from chordoma tissue samples at our institution were compared with pharmacogenomic interactions in the Comparative Toxicogenomics Database (CTD) using ksRepo, a drug-repositioning platform. Compounds selected by ksRepo were then validated in CH22 and UM-Chor1 human chordoma cells in Vitro.

RESULTS

A total of 13 chemical compounds were identified in silico from the CTD, and 6 were selected for preclinical validation in human chordoma cell lines based on their clinical relevance. Of these, 3 identified drugs are FDA-approved chemotherapies for other malignancies (cisplatin, cytarabine, and lucanthone). Cytarabine, a deoxyribonucleic acid polymerase inhibitor approved for the treatment of various leukemias, exhibited a significant concentration-dependent effect against CH22 and UM-Chor1 cells when compared to positive (THZ1) and negative (venetoclax) controls. Tretinoin exhibited a significant concentration-dependent cytotoxic effect in CH22, sacral chordoma-derived cell lines but to a much lesser extent in UM-Chor1, a cell line derived from skull base chordoma.

CONCLUSION

Cytarabine administration reduces the viability of human chordoma cells. The equally effective reduction in viability seen with tretinoin seems to be cell line dependent. Based on our findings, we recommend the evaluation of cytarabine and tretinoin in an expanded set of human chordoma cell lines and animal models.

Management of solid tumours in organ-transplant recipients

Malignancy is a well-recognised complication of transplantation and can occur de novo, as a recurrence of a pre-existing malignancy, or from transmission of malignancy from the donor. Common de-novo malignancies are those of the skin and the lymphoreticular system. Various solid-organ cancers have also been reported in transplant recipients and each poses a unique management challenge in view of the unusual setting. We review solid-organ cancers in transplant recipients and their management, including surveillance and prevention.

Phase II trial of carboplatin and infusional cyclosporine with alpha-interferon in recurrent ovarian cancer: a California Cancer Consortium Trial

The purpose of this study was to estimate the response rate of 26-h continuous infusion cyclosporine A (CSA) combined with carboplatin (CBDCA) and subcutaneous alpha-interferon (IFN), in recurrent ovarian cancer (OC), and to measure their effects on CBDCA pharmacokinetics. OC patients relapsing following platinum-based chemotherapy received CBDCA area under the curve (AUC 3) with CSA and IFN, every 3 weeks. The pharmacokinetics of CSA and CBDCA were determined in a subset of patients. Thirty patients received 84 courses of therapy. Three partial responses were observed. Nine patients were stable for >4 months. Toxicity was similar to that observed in our previously reported phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean end of infusion CSA level (high-performance liquid chromatographic assay [HPLC]) was 1109 +/- 291 microg/mL (mean +/- SD). CBDCA pharmacokinetics revealed a measured AUC of 3.61 versus a targeted AUC of 3, suggesting a possible effect of IFN on CBDCA levels versus errors in the estimation of CBDCA clearance using measured creatinine clearance. Steady-state levels of >1 microg/mL CSA (HPLC assay) are achievable in vivo. Insufficient clinical resistance reversal was observed in this study to warrant further investigation of this combination.

Phase II trial of carboplatin and infusional cyclosporine in platinum-resistant recurrent ovarian cancer

PURPOSE

To determine the response rate to 26-h continuous infusion cyclosporine A (CSA) combined with a fixed dose level of carboplatin (CBDCA) in patients with recurrent ovarian cancer, and to determine the effect of CSA on the pharmacokinetics of CBDCA.

EXPERIMENTAL DESIGN

To examine the effect of duration of CSA exposure on reversal of CBDCA resistance, clonogenic assays were performed in vitro in platinum-resistant A2780 cells. CBDCA (AUC 4) with CSA repeated every 3 weeks was then administered to patients on this phase II study. Pharmacokinetics of CSA and CBDCA were determined in a subset of patients.

RESULTS

Preincubation of platinum-resistant A2780 cells with CSA reversed CBDCA resistance in a concentration-dependent and time-dependent manner. A group of 23 patients received 58 courses of CBDCA/CSA therapy. One partial response was observed. Eight patients achieved disease stabilization. Toxicity was similar to that observed in our previous phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean +/- SD end-of-infusion CSA level (HPLC assay) was 1253 +/- 400 microg/ml. The pharmacokinetic studies suggest that CSA does not increase CBDCA AUC.

CONCLUSIONS

Steady-state levels of >1 microg/ml CSA (HPLC assay) are achievable in vivo. Modest partial reversal of platinum resistance (in one patient with an objective response and in eight patients with stable disease noted) is achievable in vivo in patients pretreated with CSA. This phenomenon is not explained by alterations in CBDCA pharmacokinetics.

Cyclosporin A reverses chemoresistance in patients with gynecologic malignancies

Multidrug resistance is a major obstacle in successful systemic therapy of gynecologic malignancies. The objectives of this study are to evaluate the activity of cyclosporin A used to overcome drug resistance in a variety of gynecologic malignancies. Forty women (29 with ovarian cancer, 7 with uterine cancer, 3 with cervical cancer, and 1 with choriocarcinoma) were treated with cyclosporin A, 4 mg/kg intravenously, 6 hours before and 18 hours after the specific chemotherapeutic agent, to which the tumor had developed drug resistance. All patients had shown resistance to the chemotherapy agent used in combination with cyclosporin A. All patients had been heavily pretreated (mean, 2.8 previous chemotherapy regimens). Overall, among 38 available patients with gynecologic malignancies, a 29% objective response rate was observed. Twenty-six (65%) of all patients received three or more cycles of cyclosporin A. There was a 25% response rate for patients with ovarian cancer patients and 50% for those with uterine cancer. There were no responses among the three patients with cervical cancer, and the patient with choriocarcinoma had a complete response. All patients were evaluable for toxicity. Leukopenia and nausea were the most common toxic reactions, but in most cases they were transient, and only three patients required a treatment delay. The most common grade 3 or 4 toxicity was thrombocytopenia, which was observed in 22% of the patients. Cyclosporin A is well tolerated and has significant potential for reversal of chemoresistance in heavily pretreated patients with ovarian and uterine malignancies.

Modulation of excision repair cross complementation group 1 (ERCC-1) mRNA expression by pharmacological agents in human ovarian carcinoma cells

Excision repair cross complementation group 1 (ERCC-1) is a DNA repair gene that is essential for life, and it appears to be a marker gene for nucleotide excision repair activity. Overexpression of ERCC-1 during cisplatin-based chemotherapy is associated with clinical and cellular drug resistance. We therefore began to assess the influence of various pharmacological agents on the induction of ERCC-1 mRNA in A2780/CP70 human ovarian carcinoma cells. Cisplatin exposure in culture resulted in a 4- to 6-fold induction for the steady-state level of ERCC-1 mRNA in A2780/CP70 cells. ERCC-1 mRNA induction was concentration and time dependent. Cyclosporin A and herbimycin A, which suppress c-fos and c-jun gene expressions, respectively, blocked the cisplatin-induced increase in ERCC-1 mRNA. This effect of cyclosporin A or herbimycin A on the down-regulation of ERCC-1 correlates with enhanced cytotoxicity of cisplatin in this system. The products of c-fos and c-jun are components of the transcription factor AP-1 (activator protein 1). 12-O-Tetradecanoylphorbol 13-acetate (TPA), a known AP-1 agonist, induced ERCC-1 mRNA to the same extent as cisplatin, but did not synergize with cisplatin in this regard. The TPA effect was biphasic, with an initial increase during the first 1-6 hr, followed by decreasing mRNA levels at 24-72 hr. These data suggest that the effects of these pharmacological agents on ERCC-1 gene expression may be mediated through the modulation of AP-1 activities.

Multiple resistance modulators combined with carboplatin for resistant malignancies: a pilot study

BACKGROUND

Chemotherapy resistance is probably multifactorial; hence, we assessed the feasibility of adding to carboplatin 6 concurrent resistance modulators in 53 patients with resistant cancers.

METHODS

Pentoxifylline and dipyridamole were added to carboplatin 400 mg/m2 in cohort 1, and metronidazole was also given in cohort 2. Mannitol and saline were administered in each cohort with the theoretical objective of improving carboplatin delivery to tumors by reducing blood viscosity. Because of excessive toxicity in cohort 2, cohort 3 received the same modulators as in cohort 2 but with a reduced dose of carboplatin (200 mg/m2). Subsequent patients had the following drugs added to those in the previous cohort: novobiocin (cohort 4), tamoxifen (cohort 5), ketoconazole (cohort 6). Cohort 7 patients received the 6 cohort 6 modulators along with carboplatin 300 mg/m2.

RESULTS

Thrombocytopenia was excessive in early cohorts with a carboplatin dose of 400 mg/m2, but was minimal at lower doses. Other toxicity was generally tolerable and reversible, particularly at carboplatin doses < or = 300 mg/m2, although gastrointestinal and neurological toxicity tended to worsen as additional modulators were added. No major responses (but 4 minor responses) were seen in this patient population with heavily pretreated or primarily resistant cancers.

CONCLUSIONS

Acceptable doses for phase II studies are carboplatin 300 mg/m2, 20% mannitol 250 ml plus normal saline 500 ml over 1 hr prior to carboplatin, pentoxifylline 700 mg/m2/day p.o. from 3 days before carboplatin to cessation of therapy, dipyridamole 100 mg/m2 p.o. q6h x 6 days starting 24 hr before carboplatin, metronidazole (750 mg/m2 p.o. 12 hr and immediately before, and 24 hr after carboplatin; 250 mg/m2 suppository p.r. 12 hr and immediately before, and 6 and 24 hr after carboplatin; and 500 mg/m2 i.v. right after carboplatin), novobiocin 600 mg/m2 p.o. q12h x 6 days starting 24 hr before carboplatin, and tamoxifen 100 mg/m2/day plus ketoconazole 700 mg/m2/day x 3 days starting the day before carboplatin, with oral dexamethasone and ondansetron as antimetics.

Evaluation of cisplatin and cyclosporin A in recurrent platinum-resistant ovarian cancer: a phase II study of the gynecologic oncology group

OBJECTIVE

The objective of this study was to study the effectiveness of cyclosporin A and cisplatin in patients with recurrent epithelial ovarian cancer. METHODS. Twenty-six patients with measurable recurrent epithelial ovarian cancer, considered to be resistant to cisplatin, received cisplatin in combination with cyclosporin A. Patients received 75 mg/m2 cisplatin every 3 weeks and two cyclosporin A injections over 2 h each, 24 h apart, at a dose of 4 mg/kg each.

RESULTS

Only a single patient had a complete response, with two experiencing a partial response to cyclosporin A/cisplatin combination. Hematologic toxicity in this study was modest. No patient developed grade 4 renal toxicity.

CONCLUSION

These data indicate minimal activity of the combination of cyclosporin A and cisplatin in ovarian cancer patients with recurrent measurable disease previously treated with cisplatin and thought to be resistant to this chemotherapeutic agent.

Promising new therapies in the treatment of advanced ovarian cancer

Advanced stage ovarian cancer is the most lethal gynecologic cancer. Despite initial response rates of 60-80% with platinum-based chemotherapy, more than 75% of women with this malignancy die of complications associated with this disease. There is a pressing need to find new chemotherapeutic agents for patients with advanced ovarian cancer. Phase II studies have identified paclitaxel as the most active drug in ovarian cancer since the introduction of cisplatin in the 1970s. Phase III studies will define the role of paclitaxel as initial therapy. Camptothecins (topotecan, CPT-11, 9-amino-camptothecin) inhibit topoisomerase I. CPT-11 and topotecan have shown activity in Phase II trials. Gemcitabine, a pyrimidine antimetabolite, has shown activity in Phase II trials. Other promising drugs (docetaxel, treosulfan) are under investigation. Modulation of drug resistance is being explored in Phase I/II studies. Clinical trials have been initiated with buthionine-sulfoximine, an inhibitor of glutathione biosynthesis, which decreases the ability of resistant cells to inactivate platinum compounds and alkylating agents. Cyclosporin has been shown to increase cisplatin cytotoxicity. Phase I trials have demonstrated the feasibility of combining cyclosporin and cisplatin. Phase II trials of cyclosporin analogs (PSC 833) and paclitaxel in refractory ovarian cancer are ongoing. Promising leads in drug development should provide new therapies for patients with ovarian cancer. Further research in the modulation of drug resistance may identify new mechanisms or strategies with which to prevent the emergence of drug resistance.