Phase II study of the combination of pegylated liposomal doxorubicin and topotecan in platinum-resistant ovarian cancer

Randomized phase II study of the PDGFRα antibody olaratumab plus liposomal doxorubicin versus liposomal doxorubicin alone in patients with platinum-refractory or platinum-resistant advanced ovarian cancer

BACKGROUND

Olaratumab is a platelet-derived growth factor receptor-α (PDGFRα)-targeting monoclonal antibody blocking PDGFRα signaling. PDGFRα expression is associated with a more aggressive phenotype and poor ovarian cancer outcomes. This randomized, open label phase II study evaluated olaratumab plus liposomal doxorubicin compared with liposomal doxorubicin alone in advanced ovarian cancer patients.

METHODS

Patients with platinum-refractory or platinum-resistant advanced ovarian cancer were randomized 1:1 to receive liposomal doxorubicin (40 mg/m², intravenous infusion) administered every 4 weeks with or without olaratumab (20 mg/kg, IV infusion) every 2 weeks. Patients were stratified based on prior response to platinum therapy (refractory vs resistant). The primary efficacy endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate, duration of response, and safety.

RESULTS

A total of 123 patients were treated (62 olaratumab+liposomal doxorubicin; 61 liposomal doxorubicin). Median PFS was 4.2 months for olaratumab+liposomal doxorubicin and 4.0 months for liposomal doxorubicin (stratified hazard ratio [HR] = 1.043; 95% confidence interval [CI] 0.698-1.558; p = 0.837). Median OS was 16.6 months and 16.2 months in the olaratumab+liposomal doxorubicin and liposomal doxorubicin arms, respectively (HR = 1.098; 95% CI 0.71-1.71). In the platinum-refractory subgroup, median PFS was 5.5 months (95% CI 1.6-9.2) and 3.7 months (95% CI 1.9-9.2) in the olaratumab+liposomal doxorubicin (n = 15) and liposomal doxorubicin arms (n = 16), respectively (HR = 0.85; 95% CI 0.38-1.91). Overall, 59.7% (olaratumab+liposomal doxorubicin) and 65.6% (liposomal doxorubicin) of patients reported grade ≥ 3 adverse events regardless of causality. The most common treatment-emergent adverse events (all grades) regardless of causality were fatigue related (61%), nausea (57%), and constipation (52%) with olaratumab+liposomal doxorubicin and nausea (64%), fatigue related (62%), and mucositis (46%) with liposomal doxorubicin.

CONCLUSIONS

The addition of olaratumab to liposomal doxorubicin did not result in significant prolongation of PFS or OS in platinum-resistant or platinum-refractory ovarian cancer.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00913835 ; registered June 2, 2009.

DOXIL when combined with Withaferin A (WFA) targets ALDH1 positive cancer stem cells in ovarian cancer

Ovarian cancer is a highly aggressive and deadly disease. Currently, the treatment for ovarian cancer entails cytoreductive surgery followed by chemotherapy, mainly cisplatin or carboplatin combined with paclitaxel. Although this regimen is initially effective in a high percentage of cases, unfortunately, after few months of initial treatment, tumor relapse occurs due to platinum-resistance. DOXIL (liposomal preparation of doxorubicin) is a choice of drug for recurrent ovarian cancer. However, its response rate is very low and is accompanied by myocardial toxicity. Resistance to chemotherapy and recurrence of cancer is primarily attributed to the presence of cancer stem cells (CSCs), a small population of cells present in cancer. Effect of DOXIL and withaferin A (WFA), both alone and in combination, was investigated on cell proliferation of ovarian cancer cell line A2780 and tumor growth in SCID mice bearing i.p. ovarian tumors. ALDH1 cells were isolated from A2780 using cell sorter, and effect of DOXIL and WFA both alone and in combination on tumorigenic function of ALDH1 was studied using spheroids formation assays in vitro. Western blots were performed to examine the expression of ALDH1 and Notch 1 genes. In our studies, we showed, for the first time, that DOXIL when combined with withaferin A (WFA) elicits synergistic effect on inhibition of cell proliferation of ovarian cancer cells and inhibits the expression of ALDH1 protein, a marker for ALDH1 positive cancer stem cells (CSCs), and Notch1, a signaling pathway gene required for self-renewal of CSCs. Inhibition of expression of both ALDH1 and Notch1 genes by WFA was found to be dose dependent, whereas DOXIL (200 nM) was found to be ineffective. SCID mice, bearing i.p. ovarian tumors, were treated with a small dose of DOXIL (2 mg/kg) in combination with a sub-optimal dose of WFA (2 mg/kg) which resulted in a highly significant (60% to 70%) reduction in tumor growth, and complete inhibition of metastasis compared to control. In contrast, WFA treatment showed a significant reduction in tumor growth but no change in metastasis compared to control. DOXIL showed non-significant reduction in tumor growth and no change in metastasis compared to control. Isolated ALDH1 positive CSCs treated with the combination of DOXIL and WFA resulted in a significant reduction in spheroids formation (tumorigenic function of CSCs) and expression of ALDH1 protein. WFA when used alone at a concentration of 1.5 μM was found to be highly effective in suppression of ALDH1 expression, whereas DOXIL at a concentration of 200 nM was found to be ineffective. DOXIL in combination with WFA elicits synergistic effects, targets cancer stem cells, and has potential to minimize induction of drug resistance and reoccurrence of cancer. Based on our studies, we conclude that the combination of DOXIL with WFA has the potential to be an effective therapy for ovarian cancer and may ameliorate DOXIL related side effects as well as recurrence of ovarian cancer leading to increase in patients' survival rate.

Clinical trials with pegylated liposomal Doxorubicin in the treatment of ovarian cancer

Among the pharmaceutical options available for treatment of ovarian cancer, increasing attention has been progressively focused on pegylated liposomal doxorubicin (PLD), whose unique formulation prolongs the persistence of the drug in the circulation and potentiates intratumor accumulation. Pegylated liposomal doxorubicin (PLD) has become a major component in the routine management of epithelial ovarian cancer. In 1999 it was first approved for platinum-refractory ovarian cancer and then received full approval for platinum-sensitive recurrent disease in 2005. PLD remains an important therapeutic tool in the management of recurrent ovarian cancer in 2012. Recent interest in PLD/carboplatin combination therapy has been the object of phase III trials in platinum-sensitive and chemonaïve ovarian cancer patients reporting response rates, progressive-free survival, and overall survival similar to other platinum-based combinations, but with a more favorable toxicity profile and convenient dosing schedule. This paper summarizes data clarifying the role of pegylated liposomal doxorubicin (PLD) in ovarian cancer, as well as researches focusing on adding novel targeted drugs to this cytotoxic agent.

Long-term results of weekly paclitaxel carboplatin induction therapy: an effective and well-tolerated treatment in patients with platinum-resistant ovarian cancer

BACKGROUND

Weekly paclitaxel/cisplatin is effective in platinum-resistant epithelial ovarian cancer (EOC). To reduce toxicity, paclitaxel/cisplatin was replaced by paclitaxel/carboplatin.

PATIENTS AND METHODS

Patients with progressive EOC after prior 3-weekly paclitaxel/carboplatin were treated with six cycles weekly paclitaxel 90 mg/m(2) and carboplatin area under the curve (AUC) 4 mg/ml/min, followed by six cycles 3-weekly paclitaxel/carboplatin. End-points were progression free survival (PFS), overall survival (OS), response rate (RR) and toxicity.

RESULTS

Median progression free interval after last platinum was 9 (0-81) months in 108 patients; 43 were platinum-resistant, of whom 13 started weekly paclitaxel/carboplatin <6 months after progression. During 633 weekly cycles grade 3/4 toxicity included; thrombocytopenia 8%, neutropenia 30%, febrile neutropenia 0.5%. Non-haematologic toxicity was low. Treatment was delayed in 16%, and dose reduced in 2% of cycles. RR was 58% for platinum-resistant and 76% for platinum-sensitive patients, median PFS were 8 (range 1-21) and 13 (1-46) months, median OS 15 (1-69) and 26 (4-93) months, respectively. The 13 platinum-resistant patients with a platinum-therapy free interval <6 months had a significant shorter PFS (4 versus 10 months, p=0.035) and OS (9 versus 15 months, p=0.002).

CONCLUSION

Six cycles weekly paclitaxel/carboplatin followed by six 3-weekly cycles is well-tolerated and highly active in platinum-resistant and platinum-sensitive patients.

Pegylated liposomal doxorubicin/carboplatin combination in ovarian cancer, progressing on single-agent pegylated liposomal doxorubicin

AIM: To assess the efficacy and safety of the combination of pegylated liposomal doxorubicin (PLD) and carboplatin in patients with recurrent epithelial ovarian carcinoma (ROC), following disease progression on single agent PLD.

METHODS: An analysis of the medical records of 10 patients with ROC, treated in our institution with a combination of PLD and carboplatin following progression on single-agent PLD therapy was performed. The median age was 59.1 years (range, 45 to 77 years). All diagnoses were histological-proven. Eight of the 10 patients were platinum-resistant. Following disease progression on single-agent PLD treatment, carboplatin area under the curve (AUC)-5 was added to PLD in all 10 patients. In order to assess disease status, Ca-125 was assessed before each PLD/carboplatin treatment. Relative changes in Ca-125 values were calculated, and response defined as a greater than 50% reduction in Ca-125 from baseline. Radiographic studies were re-evaluated and responses to therapy based on computer tomography (CT) scans carried out on a regular basis every 2-3 mo in each patient. Statistical analysis was performed using SPSS (V19).

RESULTS: A median of 10 cycles (range, 2-26) of the carboplatin-PLD combination was given. Of the 10 treated patients, 6 had > 50% reduction in Ca-125 levels from baseline, 4 of these had a partial response according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and the other 2 patients had no measurable disease. In a further 2 patients with a best response of disease stabilization and < 50% reduction of Ca-125 levels, one had progression of disease after 26 cycles, and the second progressed with brain metastases following 12 cycles. Seven of the eight patients who were platinum-resistant showed evidence of clinical benefit on carboplatin-PLD combination therapy; 5 of these had > 50% reduction in Ca-125 level, 4 also showed a partial response on CT scan. The treatment was generally well-tolerated by the patients.

CONCLUSION: Addition of carboplatin to PLD, after disease progression on single-agent PLD therapy, is both effective and safe in patients with ROC, even in those with Platinum-resistant disease.

Phase II study of gemcitabine and docetaxel in recurrent platinum resistant ovarian cancer

To evaluate the activity of gemcitabine and docetaxel in patients with recurrent ovarian cancer.

METHODS

Patients with platinum-resistant disease and prior treatment with paclitaxel received treatment with docetaxel on day 1 and gemcitabine on days 1 and 8, repeated every three weeks.

RESULTS

Twenty patients, with a platinum-free interval of three months, were enrolled. Overall response rate was 25%. Treatment was associated with significant myelosuppression.

CONCLUSIONS

In chemotherapy-resistant patients, this regimen exhibited encouraging activity. Excessive myelosuppression led to early closure. This was prevented by administering docetaxel on day 8 (instead of day 1) and prophylactic use of G-CSF.

Pharmacokinetic and toxicity considerations for the use of anthracyclines in ovarian cancer treatment

INTRODUCTION

Safe and effective treatments are needed for ovarian cancer. While there are many drugs currently available, there has recently been a renewed novel interest in the use of anthracyclines.

AREAS COVERED

This review summarizes the available evidence on pharmacokinetic (PK) and toxicology implications of anthracyclines and pegylated liposomal doxorubicin (PLD) in the clinical management of women with epithelial ovarian cancer. This article consists of material obtained via Medline, PubMed and EMBASE literature searches, up to September 2010.

EXPERT OPINION

PLD is a liposomal formulation of doxorubicin (DXR), with a distinct pharmacokinetic profile, characterized by extended circulation time and a reduced clearance and volume of distribution with respect to the free drug. PLD is effective and well tolerated in relapsed ovarian cancer. The toxicity profile of PLD is characterized by dose-limiting mucosal and cutaneous toxicities, mild myelosuppression and decreased cardiotoxicity compared to free DXR. The good response rate, toxicity profile and pharmacokinetic profile of PLD suggest that PLD could be an option in first-line and second-line treatment in ovarian cancer; especially in those who had experienced taxane-induced toxicity or had a poor performance status.

Overcoming platinum resistance in ovarian carcinoma

IMPORTANCE OF THE FIELD

Ovarian cancer remains a deadly malignancy because most patients develop recurrent disease that is resistant to chemotherapy, including platinum. Because response rates for current treatment regimens are relatively similar and unfortunately low, no standard chemotherapy for platinum-resistant ovarian cancer exists.

AREAS COVERED IN THIS REVIEW

A systematic literature review of clinical studies published between January 2005 and March 2010 was conducted using search engines, PubMed and MEDLINE with the entry keywords 'ovarian cancer' and 'platinum resistance'. This search revealed 40 clinical trials (1793 patients).

WHAT THE READER WILL GAIN

Gemcitabine was the most common drug used in clinical trials reporting higher response rates, ≥ +1 SD of overall response rate (5 out of 8). Gemcitabine-based combination therapy showed an average response rate of 27.2% (95% CI, 22.4-32.0). Combination of gemcitabine and pegylated liposomal doxorubicin (PLD) was the most common regimen (n = 3) and was associated with possible additive effects in platinum-resistant ovarian cancer patients: response rate, gemcitabine alone 6.1%, PLD alone 19.8%, and gemcitabine with PLD 28.7% (95% CI, 20.4-37.0), respectively.

TAKE HOME MESSAGE

Analysis of recent clinical trials showed that gemcitabine-based combination chemotherapy was associated with the highest antitumor effects in platinum-resistant ovarian cancer patients during the study period.

Pegylated liposomal doxorubicin in the management of ovarian cancer

Among the pharmaceutical options available for treatment of ovarian cancer, much attention has been progressively focused on pegylated liposomal doxorubicin (PLD), whose unique formulation, which entraps conventional doxorubicin in a bilayer lipidic sphere surrounded by a polyethylene glycol layer, prolongs the persistence of the drug in the circulation and potentiates intratumor drug accumulation. These properties enable this drug to sustain its very favorable toxicity profile and to be used safely in combination with other drugs. PLD has been already approved for treatment of advanced ovarian cancer patients failing first-line platinum-based treatment. Moreover, phase III trials have been already completed, and results are eagerly awaited, which hopefully will expand the range of PLD clinical application in this neoplasia both in front-line treatment, and in the salvage setting in combination with other drugs. Moreover, attempts are continuing to enable this drug to be combined with novel cytotoxic drugs and target-based agents. This review aims at summarizing the available evidence and the new perspectives for the clinical role of PLD in the management of patients with epithelial ovarian cancer.

Treatment for recurrent ovarian cancer-at first relapse

Recurrent ovarian cancer is a lethal disease, and few patients can be cured. Although most patients receive standardized surgery and chemotherapy, the status of recurrent disease is heterogeneous. The site of recurrence and the survival intervals after recurrence are also widely distributed. Among a number of factors, many clinical trials identified time to recurrence was the factor most related to chemosensitivity at first relapse. The current recommendation for platinum sensitive ovarian cancer is a carboplatin containing combination chemotherapy. Generally, a single agent is chosen for platinum resistant ovarian cancer. Patients with single site recurrence and a long disease free interval are candidates for secondary cytoreduction, which may provide longer survival. There are several treatment choices at first relapse, and disease status, chemotherapy-free interval, and the patient's condition play a major role in the decision making process.

Pegylated liposomal doxorubicin in ovarian cancer

The encapsulation of doxorubicin in a pegylated liposomal matrix led to a reformulated agent with a different toxicity profile and improved clinical utility. Liposomal doxorubicin is devoid of the cardiac toxicity associated with doxorubicin, but is associated with predictable muco-cutaneous toxicity. The liposomal formulation leads to improved delivery to the target tumor tissue, allowing enhanced uptake by cancer cells. These properties translate into clinical utility in recurrent ovarian cancer as demonstrated by phase II and III trials, this proven clinical efficacy leading to FDA approval in second-line therapy for ovarian cancer. New combinations with cytotoxics, in particular with carboplatin, have demonstrated an acceptable toxicity profile and clinical utility in platinum-sensitive ovarian cancer. A favorable toxicity profile renders liposomal doxorubicin an ideal partner for combination regimens with other cytotoxics, and more recently with biological agents. Such combinations are the subject of ongoing clinical trials.

Current role and future aspects of topotecan in relapsed ovarian cancer

BACKGROUND

Ovarian cancer is the fifth leading cause of cancer deaths in women. It is associated with a poor prognosis, as the majority of patients present with advanced disease and relapse after radical surgery, and following chemotherapy with carboplatin and paclitaxel.

OBJECTIVE

To review the role of topotecan in the treatment of advanced and relapsed ovarian cancer, and the efficacy and safety of novel dosing regimens and formulations of topotecan. It will also discuss further options of combination of topotecan with other cytotoxic agents and targeted therapies.

RESEARCH DESIGN AND METHODS

The authors searched for relevant references in the MEDLINE database and in congress abstracts of the American Society of Clinical Oncology.

RESULTS

Topotecan is an established second-line therapy for advanced and relapsed ovarian cancer; a regimen of 1.5 mg/m(2)/day 1-5 has been approved in the USA and many other western countries. Topotecan is well tolerated; associated haematological toxicity is generally manageable, reversible and non-cumulative. A number of alternative dosing regimens and formulations have been investigated in an attempt to improve the toxicity profile of topotecan without compromising anti-tumour activity. A novel oral formulation of topotecan has shown clinical promise in patients with advanced and relapsed disease. Administration of i.v. topotecan on a weekly basis produced encouraging results in several phase II trials, with less haematological toxicity and similar response rates to the day 1-5 regimen. Also, recent early studies demonstrate that topotecan is effective in combination with several other therapeutic agents in the relapsed setting.

CONCLUSION

The peer-reviewed literature reports that topotecan is an effective, well tolerated treatment option for relapsed ovarian cancer.

Topotecan for ovarian cancer

BACKGROUND

Chemotherapeutic agents such as topotecan can be used to treat ovarian cancer. The effects of using topotecan as a therapeutic agent have not been previously been systematically reviewed.

OBJECTIVES

To systematically evaluate the effectiveness and safety of topotecan for the treatment of ovarian cancer.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), (Issue 4, 2006); Cochrane Gynaecological Cancer Review Group (CGCRG) Specialised Register (Cochrane Library Issue 4, 2006); MEDLINE (January 1990 to 27 July 2006); EMBASE (January 1990 to 27 July 2006); The European Organization for the Research and Treatment of Cancer (EORTC) database (to 1 August 2006); CBM (Chinese Biomedical Database) (January 1990 to 27 July 2006).

SELECTION CRITERIA

Randomised controlled trials (RCTs) which randomized patients with ovarian cancer to single or combined use of topotecan versus interventions without topotecan, or different remedies of topotecan.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and analysed data.

MAIN RESULTS

Six studies including 1323 participants were eligible for this review (Gordon 2004a; Gore 2001a; Gore 2002; Hoskins 1998; Huinink 2004; Placido 2004) All studies, as reported, were identified as being of poor methodological quality. Topotecan had comparable effectiveness to prolong progression-free survival (PFS) compared with pegylated liposomal doxorubicin (PLD), (16.1 weeks versus 17.0 weeks; p = 0.095). Overall survival (OS) time was similar in participants using PLD compared with topotecan (56.7 weeks versus 60 weeks; p = 0.341). Topotecan was more hematologically toxic compared with paclitaxel or PLD, relative risks (RRs) of hematological events: ranged from 1.03 to 14.46 and 1.73 to 27.12 respectively. A 21-day cycle of topotecan was more toxic than a 42-day cycle (RRs of hematological and non-hematological events ranged from 1.03 to 8). Intravenous and oral topotecan had comparable toxicity. Topotecan delayed progression more effectively compared with paclitaxel (23.1 weeks versus 14 weeks, p = 0.0021). Participants were more likely to respond to topotecan on a 21-day cycle as opposed to a 42-day cycle (RR 7.23, 95% CI 0.94 to 55.36). Small tumor diameter, sensitivity to platinum-based chemotherapy was associated with better prognosis. Small sample size, methodological flaws and poor reporting of the included trials made measurement bias of the trials difficult to assess.

AUTHORS' CONCLUSIONS

Topotecan appears to have a similar level of effectiveness as paclitaxel and PLD, though with different patterns of side effects. Larger, well-designed RCTs are required in order to define an optimal regime.

Determination of the optimal combination chemotherapy regimen for treatment of platinum-resistant ovarian cancer in nude mouse model

OBJECTIVE

The primary objective of this study was to evaluate the potential to increase the in vivo activity of liposomal doxorubicin when administered in combination with other chemotherapeutic agents such as topotecan, docetaxel, gemcitabine, capecitabine, or celecoxib in an ovarian cancer xenograft mouse model to identify new treatment options for recurrent platinum-sensitive/resistant ovarian cancer.

METHODS

This was a five-arm study in two xenograft ovarian cancer mouse models, ES-2 (platinum-sensitive), and OVCAR3 (platinumresistant), to evaluate the combination of liposomal doxorubicin with the common chemotherapeutic agents. Each cell line had five mice for each treatment arm, five vehicle control mice, and five liposomal doxorubicin alone control mice. Experiments were done in duplicate.

RESULTS

The percentage tumor reduction ranged from 52% to 74.1% for the single-agent treatment arms. Tumor growth inhibition and regression (response) was improved on the combination treatment arms ranging from 76.1% to 100%. We observed increased activity in the liposomal doxorubicin plus topotecan arm, with a 27.3% improvement in response, compared with either agent alone.

CONCLUSIONS

The addition of liposomal doxorubicin demonstrated increased antitumor activity compared with either agent used alone. The most active combination treatment arm was liposomal doxorubicin with topotecan which is consistent with recent clinical study reports of enhanced activity with the combination of topoisomerase I and topoisomerase II agents. Additional studies are warranted to evaluate the efficacy and safety to optimize the combination of liposomal doxorubicin and topotecan for the treatment of recurrent or refractory ovarian cancer.

Role of pegylated liposomal doxorubicin (Caelyx) in the treatment of relapsing ovarian cancer

The most significant factor predicting response to second-line chemotherapy is the time interval elapsed from the end of chemotherapy to relapse occurrence. Two types of situations may be considered: patients with platinum-sensitive relapse (relapse-free interval longer than 6 months) and patients with platinum-refractory relapse (progression during treatment or relapse-free interval under 6 months). Pegylated liposomal doxorubicin is a doxorubicin formulation. Encapsulation in liposomes confers it different pharmacokinetic characteristics and a more favorable toxicity profile. The following review examines the efficacy and safety of pegylated liposomal doxorubicin for the treatment of relapsing epithelial ovarian cancer.

Topotecan in the management of cervical cancer

Topotecan, a semisynthetic camptothecin, exerts its cytotoxic effect through inhibition of DNA topoisomerase I. Single-agent topotecan has demonstrated activity against persistent, metastatic and recurrent cancer of the uterine cervix. When combined with cisplatin in Phase II trials, further improved response rates have been reported. The cisplatin/topotecan doublet subsequently proved to be the first regimen in a series of multiple Phase III studies to demonstrate improved disease-free and overall survival in this setting compared with cisplatin alone, thus leading to its third indication by both the US FDA and the European Medicines Agency in 2006. This survival advantage was achieved at the expense of an increase in grade 3-4 hematologic toxicity; however, there was no difference in patient-reported quality of life between the cisplatin/topotecan doublet and single-agent cisplatin. This article reviews the pharmacology of topotecan and its evolution as an active agent in advanced and metastatic cervical cancer that is not amenable to cure with surgery or radiotherapy.