Myotax: a phase II trial of docetaxel plus non-pegylated liposomal doxorubicin as first-line therapy of metastatic breast cancer previously treated with adjuvant anthracyclines

Production of Targeted Estrone Liposomes Using a Herringbone Micromixer

Liposomes are spherical vesicles formed from bilayer lipid membranes that are extensively used in targeted drug delivery as nanocarriers to deliver therapeutic reagents to specific tissues and organs in the body. Recently, we have reported using estrone as an endogenous ligand on doxorubicin-encapsulating liposomes to target estrogen receptor (ER)-positive breast cancer cells. Estrone liposomes were synthesized using the thin-film hydration method, which is a long, arduous, and multistep process. Here, we report using a herringbone micromixer to synthesize estrone liposomes in a simple and rapid manner. A solvent stream containing the lipids was mixed with a stream of phosphate buffer saline (PBS) inside a microchannel integrated with herringbone-shaped ridges that enhanced the mixing of the two streams. The small scale involved enabled rapid solvent exchange and initiated the self-assembly of the lipids to form the required liposomes. The effect of different parameters on liposome size, such as the ratio between the flow rate of the solvent and the buffer solutions (FRR), total flow rate, lipid concentrations, and solvent type, were investigated. Using this commercially available chip, we obtained liposomes with a radius of 66.1 ± 11.2 nm (mean ± standard deviation) and a polydispersity of 22% in less than 15 minutes compared to a total of  ∼  11 hours using conventional techniques. Calcein was encapsulated inside the prepared liposomes as a model drug and was released by applying ultrasound at different powers. The size of the prepared liposomes was stable over a period of one month. Overall, using microfluidics to synthesize estrone liposomes simplified the procedure considerably and improved the reproducibility of the resulting liposomes.

Anthracyclines Strike Back: Rediscovering Non-Pegylated Liposomal Doxorubicin in Current Therapeutic Scenarios of Breast Cancer

Anthracyclines are among the most active chemotherapies (CT) in breast cancer (BC). However, cardiotoxicity is a risk and peculiar side effect that has been limiting their use in clinical practice, especially after the introduction of taxanes. Non-pegylated liposomal doxorubicin (NPLD) has been developed to optimize the toxicity profile induced by anthracyclines, while maintaining its unquestionable therapeutic index, thanks to its delivering characteristics that increase its diffusion in tumor tissues and reduce it in normal tissues. This feature allows NPLD to be safely administered beyond the standard doxorubicin maximum cumulative dose of 450-480 mg/m2. Following three pivotal first-line phase III trials in HER2-negative metastatic BC (MBC), this drug was finally approved in combination with cyclophosphamide in this specific setting. Given the increasing complexity of the therapeutic scenario of HER2-negative MBC, we have carefully revised the most updated literature on the topic and dissected the potential role of NPLD in the evolving therapeutic algorithms.

Pegylated liposomal doxorubicin (Lipo-Dox®) combined with cyclophosphamide and 5-fluorouracil is effective and safe as salvage chemotherapy in taxane-treated metastatic breast cancer: an open-label, multi-center, non-comparative phase II study

Background

Anthracycline and taxane are classes of drugs that are frequently used in the adjuvant and palliative settings of metastatic breast cancer (MBC); however, treatment failure occurs in most cases. Limited data demonstrated favorable response in MBC after previous taxane-based treatment. The aim of this study was to evaluate the efficacy and safety of pegylated liposomal doxorubicin (Lipo-Dox®) used as part of a combination salvage therapy for patients with MBC whose tumors progressed during or after taxane-based treatment.

Methods

Patients with MBC who failed to respond to previous taxane-based treatments were recruited. Treatment with pegylated liposomal doxorubicin (40 mg/m²), cyclophosphamide (500 mg/m²), and 5-fluorouracil (500 mg/m²) was administered every 3 weeks. Tumor response to treatment was determined by using the Response Evaluation Criteria in Solid Tumor criteria version 1.0, and left ventricular ejection fraction was measured before and after treatment using echocardiography. Each patient was followed for 30 days after the last dose of study medication or until resolution/stabilization of any drug-related adverse event.

Results

Forty-five patients were recruited. As of December 2012, the median follow-up duration was 29.8 months, the overall response rate was 41.9 %, the median progression-free survival was 8.2 months, and the median overall survival was 36.6 months for all treated patients. Grade 3/4 neutropenia, leucopenia, and neutropenic fever were observed in 14 %, 9 %, and 1 % of the cycles, respectively. Other non-hematologic adverse effects were mild to moderate and were manageable. No decrease in left ventricular ejection function was noted.

Conclusion

This regimen of combined of pegylated liposomal doxorubicin, cyclophosphamide, and 5-fluorouracil exhibited a promising overall response rate, progression-free survival rate, and overall survival rate, with a safe cardiac toxicity profile and manageable adverse effects. This regimen could be considered as a treatment option for patients with MBC whose tumors progressed during or after taxane-based treatment.

Non-pegylated liposomal Doxorubicin-cyclophosphamide in sequential regimens with taxanes as neoadjuvant chemotherapy in breast cancer patients

PURPOSE

Chemotherapy regimens containing anthracyclines and taxanes represent the landmark of neoadjuvant systemic therapy of breast cancer. In advanced breast cancer patients liposomal anthracyclines (LA) have shown similar efficacy and less cardiac toxicity when compared to conventional anthracyclines. We performed this retrospective analysis in order to evaluate the efficacy and tolerability of neoadjuvant regimens including LA outside of clinical trials in routine clinical practice.

METHODS

Fifty operable or locally advanced, HER2 negative, breast cancer patients were retrospectively identified in 5 Italian cancer centres. Nineteen patients had received 4 cycles of non-pegylated liposomal doxorubicin (NPLD) and cyclophosphamide, followed by 4 cycles of docetaxel, every 3 weeks. In 25 patients the reverse sequence was employed, and a third subgroup of 6 patients received 4 cycles of NPLD/cyclophosphamide every 3 weeks followed by 4 cycles of weekly carboplatin and paclitaxel.

RESULTS

We observed 10 pathological complete responses (pCR) (20.0%, 95%CI, 9% to 31%), and 35 (70%, 95%CI, 57.3% to 82.7%) partial responses (pPR), whereas no patients progressed onto therapy. In the small subset of triple negative tumors the pCR rate was 37.5%, and in tumors expressing ER and/or PgR it was 16.7%. A pCR rate of 26.5% was observed in tumors with high Ki-67, whereas in tumors with low Ki-67 only one (6.2%) pCR was observed (p=0.14). Treatments were well tolerated. The most common toxicities were myelosuppression and palmar-plantar erytrodysesthesia; 4 asymptomatic and transient LVEF decrease have been recorded, without any case of clinical cardiotoxicity.

CONCLUSIONS

NPLD-cyclophosphamide and taxanes sequential regimens were proven effective and well tolerated in breast cancer patients with contra-indication to conventional anthracyclines undergoing neoadjuvant chemotherapy, even outside of clinical trials in everyday clinical practice.

Liposomal Doxorubicin in the treatment of breast cancer patients: a review

Drug delivery systems can provide enhanced efficacy and/or reduced toxicity for anticancer agents. Liposome drug delivery systems are able to modify the pharmacokinetics and biodistribution of cytostatic agents, increasing the concentration of the drug released to neoplastic tissue and reducing the exposure of normal tissue. Anthracyclines are a key drug in the treatment of both metastatic and early breast cancer, but one of their major limitations is cardiotoxicity. One of the strategies designed to minimize this side effect is liposome encapsulation. Liposomal anthracyclines have achieved highly efficient drug encapsulation and they have proven to be effective and with reduced cardiotoxicity, as a single agent or in combination with other drugs for the treatment of either anthracyclines-treated or naïve metastatic breast cancer patients. Of particular interest is the use of the combination of liposomal anthracyclines and trastuzumab in patients with HER2-overexpressing breast cancer. In this paper, we discuss the different studies on liposomal doxorubicin in metastatic and early breast cancer therapy.