Phase III randomized trial of second-line ixabepilone versus paclitaxel or doxorubicin in women with advanced endometrial cancer

Pucotenlimab in patients with advanced mismatch repair-deficient or microsatellite instability-high solid tumors: A multicenter phase 2 study

We report a multicenter, phase 2 study evaluating the efficacy of pucotenlimab, an anti-PD-1 antibody, in patients with mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) tumors, and potential biomarkers for response. Overall, 100 patients with previously treated, advanced solid tumors centrally confirmed as dMMR or MSI-H received pucotenlimab at 200 mg every 3 weeks. The most common cancer type is colorectal cancer (n = 71). With a median follow-up of 22.5 months, the objective response rate is 49.0% (95% confidence interval 38.86%-59.20%) as assessed by the independent review committee, while the median progression-free survival and overall survival have not been reached. Grade ≥3 treatment-related adverse events were observed in 18 patients. For the biomarker analysis, responders are enriched in patients with mutations in the KMT2D gene. Pucotenlimab is an effective treatment option for previously treated advanced dMMR/MSI-H solid tumors, and the predictive value of KMT2D mutation warrants further research. This study is registered with ClinicalTrials.gov: NCT03704246.

Ipatasertib, an oral AKT inhibitor, in combination with carboplatin exhibits anti-proliferative effects in uterine serous carcinoma

PURPOSE

Uterine serous carcinoma (USC) exhibits worse survival rates compared to the endometrioid subtype, and there is currently no effective treatment options for recurrence of this disease after platinum-based chemotherapy. Activation of PIK3CA/AKT/mTOR signaling pathway is a common biological feature in USC.

MATERIALS AND METHODS

Ipatasertib (IPAT) is an investigational, orally administered, ATP-competitive, highly selective inhibitor of pan AKT that has demonstrated anti-proliferative activity in a variety of tumor cells and tumor models. In this study, we used IPAT, carboplatin and their combination to investigate the anti-tumor activity in SPEC-2 and ARK-1 cells.

RESULTS

Our results indicate that IPAT combined with carboplatin at low doses was more effective at reducing proliferation, inducing apoptosis and causing cellular stress than IPAT or carboplatin alone. In particular, inhibition of the PIK3CA/AKT/mTOR pathway and induction of DNA damage were involved in the synergistic inhibition by combination treatment of cell viability in USC cells treated with the combination. Furthermore, IPAT in combination with carboplatin significantly reduced cell adhesion and inhibited cell invasion.

CONCLUSIONS

These findings suggest that the combination of IPAT and carboplatin has potential clinical implications for developing new USC treatment strategies.

Activity of pembrolizumab and lenvatinib in mismatch repair deficient (dMMR) endometrial cancer patients who have failed pembrolizumab monotherapy: A case series

To evaluate the efficacy of the combination of pembrolizumab and lenvatinib in MMR deficient (dMMR) endometrial cancer (EC) patients who previously failed to respond to single-agent pembrolizumab. A retrospective review of MMR deficient endometrial cancer patients was performed. Patients who failed to respond to pembrolizumab as a single-agent and subsequently received a combination of pembrolizumab and lenvatinib were analyzed. RECIST 1.1 criteria was used to establish clinical response (complete response, partial response, stable disease, and progression) based on CT and/or PET, comparing imaging before and after the addition of lenvatinib. Radiologic review was conducted by an independent radiologist. Eight patients with dMMR EC meeting treatment criteria were identified. The patients' ages ranged from 54 to 80 and all tumors identified were of endometrioid histology. Initial pathologic stage ranged from FIGO stage IB to IVB and recurrence confirmed via imaging or tissue biopsy. Patients received a median of 14 cycles of therapy with pembrolizumab and lenvatinib (range 1-39). All patients had decrease in measurable disease with an objective response of 75 % (PR 62.5 %, CR 12.5 %). Both patients who received the initial recommended dose of 20 mg daily required a dose reduction. Based on this retrospective study, patients with dMMR EC without significant benefit from pembrolizumab monotherapy have a significant clinical response after the addition of lenvatinib. Combination therapy should be considered for dMMR EC patients who fail pembrolizumab monotherapy.

Lurbinectedin in patients with pretreated endometrial cancer: results from a phase 2 basket clinical trial and exploratory translational study

Second-line treatment of endometrial cancer is an unmet medical need. Lurbinectedin showed promising antitumor activity in a phase I study in combination with doxorubicin in advanced endometrial cancer. This phase 2 Basket trial evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 73 patients with pretreated endometrial cancer. The primary endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety and an exploratory translational study. Confirmed complete (CR) and partial response (PR) was reported in two and six patients, respectively (ORR = 11.3%; 95%CI, 5.0-21.0%). Median DoR was 9.2 months (95%CI, 3.4-18.0 months), median PFS was 2.6 months (95%CI, 1.4-4.0 months) and median OS was 9.3 months (95%CI, 6.1-12.8 months). Molecular subtypes showed differences in PFS rate at 6 months (p53abn 23.7% vs. "No Specific Molecular Profile" [NSMP] 42.9%) and median OS (p53abn 6.6 months vs. NSMP 16.1 months). The most common treatment-related adverse events (mostly grade 1/2) were fatigue (54.8% of patients), nausea (50.7%), vomiting (26.0%) decreased appetite (17.8%). and constipation, (19.2%). The most common grade 3/4 toxicity was neutropenia (43.8%; grade 4, 19.2%; febrile neutropenia, 4.1%). In conclusion, considering the exploratory aim of this trial and the hints of antitumor activity observed together with a predictable and manageable safety profile, further biomarker-based development of lurbinectedin is recommended in this indication in combination with other agents. Clinicaltrials.gov identifier: NCT02454972.

Lenvatinib Plus Pembrolizumab in Previously Treated Advanced Endometrial Cancer: Updated Efficacy and Safety From the Randomized Phase III Study 309/KEYNOTE-775

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report the final prespecified analysis for overall survival (OS), along with updated progression-free survival (PFS) and objective response rate (ORR), and safety from the open-label, randomized, phase III Study 309/KEYNOTE-775. In total, 827 patients with advanced, recurrent, or metastatic endometrial cancer (EC) were randomly assigned to receive lenvatinib 20 mg orally once daily plus pembrolizumab 200 mg intravenously once every 3 weeks (n = 411) or chemotherapy of the treating physician's choice (doxorubicin 60 mg/m2 intravenously once every 3 weeks or paclitaxel 80 mg/m2 intravenously once weekly [3 weeks on; 1 week off] [n = 416]). Efficacy was reported for patients with mismatch repair proficient (pMMR) tumors and all-comers, and by subgroups (histology, prior therapy, MMR status). Updated safety was also reported.Lenvatinib plus pembrolizumab showed benefits in OS (pMMR HR, 0.70; 95% CI, 0.58 to 0.83; all-comer HR, 0.65; 95% CI, 0.55 to 0.77), PFS (pMMR HR, 0.60; 95% CI, 0.50 to 0.72; all-comer HR, 0.56; 95% CI, 0.48 to 0.66), and ORR (pMMR patients, 32.4% v 15.1%; all-comers, 33.8% v 14.7%) versus chemotherapy. OS, PFS, and ORR favored lenvatinib plus pembrolizumab in all subgroups of interest. No new safety signals were observed. Lenvatinib plus pembrolizumab continued to show improved efficacy versus chemotherapy and manageable safety in patients with previously treated advanced EC.

Preparation and physicochemical properties of cisplatin and doxorubicin encapsulated by niosome alginate nanocarrier for cancer therapy

Alginate (AL), in the form of a hydrogel, is extensively used in drug delivery. In the current study, an optimum formulation of alginate-coated niosome-based nanocarriers for co-delivery of doxorubicin (Dox) and cisplatin (Cis) was obtained for the treatment of breast and ovarian cancers in an attempt to decrease drug doses and overcome multidrug resistance. The physiochemical characteristics of uncoated niosomes containing Cis and Dox (Nio-Cis-Dox) compared to alginate-coated niosomes formulation (Nio-Cis-Dox-AL). The three-level Box-Behnken method was examined to optimize the particle size, polydispersity index, entrapment efficacy (%), and percent drug release of nanocarriers. Nio-Cis-Dox-AL showed appropriate encapsulation efficiencies of 65.54 ± 1.25 % and 80.65 ± 1.80 % for Cis and Dox, respectively. Maximum drug release decreased from niosomes in case coated by alginate. Also, the zeta potential value of Nio-Cis-Dox nanocarriers decreased after coating with alginate. In vitro cellular and molecular experiments were performed to investigate the anticancer activity of Nio-Cis-Dox and Nio-Cis-Dox-AL. MTT assay showed the IC₅₀ of Nio-Cis-Dox-AL was much lower than the Nio-Cis-Dox formulations and free drugs. Cellular and molecular assays demonstrated that Nio-Cis-Dox-AL caused significant increase in apoptosis induction rate and cell cycle arrest in MCF-7 and A2780 cancer cells, as compared to Nio-Cis-Dox and free drugs. Also, the Caspase 3/7 activity increased after treatment with coated niosomes compared to uncoated nisomes and the drug-free case. Synergetic cell proliferation inhibitory impacts of Cis and Dox were demonstrated against MCF-7 and A2780 cancer cells. All anticancer experimental data demonstrated that the co-delivery of Cis and Dox through alginate-coated niosomal nanocarriers was effective for ovarian and breast cancer treatment.

Understanding Characteristics, Treatment Patterns, and Clinical Outcomes for Individuals with Advanced or Recurrent Endometrial Cancer in Alberta, Canada: A Retrospective, Population-Based Cohort Study

Endometrial cancer (EC) incidence has increased in recent decades. However, population-based outcomes data are limited. In this retrospective cohort study, we examined characteristics, treatment patterns, and clinical outcomes, including time to next treatment (TNNT) and overall survival (OS), among advanced/recurrent (A/R) EC patients between 2010 and 2018 in Alberta, Canada. Kaplan-Meier statistics evaluated TTNT and OS, stratified by patient (A/R) and treatment. A total of 1053 patients were included: 620 (58.9%) advanced and 433 (41.1%) recurrent. A total of 713 (67.7%) patients received first-line therapy: 466 (75.2%) advanced and 247 (57.0%) recurrent. Platinum-based chemotherapy (PBCT) was the most common first-line regimen (overall: 78.6%; advanced: 96.1%; recurrent: 45.3%). The median TTNT and OS from first-line therapy were 19.9 months (95% confidence interval [CI]: 17.5-23.5) and 35.9 months (95% CI: 31.5-53.5), respectively. Following first-line PBCT, the median OS from second-line chemotherapy (N = 187) was 10.4 months (95% CI: 8.9-13.3) and higher for those rechallenged with PBCT (N = 72; 38.5%) versus no rechallenge (N = 115; 61.5%) (13.3 months [95% CI: 11.2-20.9] vs. 6.4 months [95% CI: 4.6-10.4; p < 0.001]). The findings highlight poor outcomes in A/R EC, particularly following first-line therapy, and that additional tolerable therapeutic options are needed to improve patient outcomes.

A Phase Ib/II Study of Lenvatinib and Pembrolizumab in Advanced Endometrial Carcinoma (Study 111/KEYNOTE-146): Long-Term Efficacy and Safety Update

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The open-label phase Ib/II Study 111/KEYNOTE-146 of daily lenvatinib 20 mg plus pembrolizumab 200 mg once every 3 weeks showed promising efficacy and tolerable safety in patients with previously treated advanced endometrial carcinoma (EC; primary data cutoff date: January 10, 2019). This updated analysis reports long-term follow-up efficacy and safety data from 108 patients with previously treated EC included in the primary analysis. End points included objective response rate, duration of response, progression-free survival, overall survival, and safety. Investigators performed tumor assessments per immune-related RECIST. At the updated data cutoff date (August 18, 2020), the median study follow-up duration was 34.7 months (95% CI, 30.9 to 41.2), the objective response rate was 39.8% (95% CI, 30.5 to 49.7), and the median duration of response was 22.9 months (95% CI, 10.2 to not estimable). The median progression-free survival and overall survival were 7.4 months (95% CI, 5.2 to 8.7) and 17.7 months (95% CI, 15.5 to 25.8), respectively. Treatment-related treatment-emergent adverse events of any grade occurred in 104 (96.3%) patients. The most common grade ≥ 3 treatment-related treatment-emergent adverse events were hypertension (33.3%), elevated lipase (9.3%), fatigue (8.3%), and diarrhea (7.4%). The results demonstrate extended efficacy and tolerability of lenvatinib plus pembrolizumab in this cohort of patients with previously treated advanced EC.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with endometrial cancer

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with endometrial cancer was published in 2022. It was therefore decided, by both the ESMO and the Indian Society of Medical and Paediatric Oncology (ISMPO), to convene a virtual meeting in July 2022 to adapt the ESMO 2022 guidelines to take into account the variations in the management of endometrial cancer in Asia. These guidelines represent the consensus opinion of a panel of Asian experts representing the oncological societies of China (CSCO), India (ISMPO), Indonesia (ISHMO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO). Voting was based on scientific evidence and was conducted independently of the current treatment practices and treatment access constraints in the different Asian countries, which were discussed when appropriate. The aim of this guideline manuscript is to provide guidance for the optimisation and harmonisation of the management of patients with endometrial cancer across the different regions of Asia, drawing on the evidence provided by Western and Asian trials whilst respecting the variations in clinical presentation, diagnostic practices including molecular profiling and disparities in access to therapeutic options, including drug approvals and reimbursement strategies.

Looking beyond carboplatin and paclitaxel for the treatment of advanced/recurrent endometrial cancer

Endometrial cancer incidence and mortality are rising among all ethnic groups. Carboplatin plus paclitaxel is the established frontline treatment for advanced/recurrent disease; however, subsequent treatment with traditional cytotoxic chemotherapy is challenging. The molecular characterization of endometrial cancer has provided important insights into the biological drivers of carcinogenesis, which has allowed for the development of newer precision immunotherapies and targeted therapies, including pembrolizumab, dostarlimab, and lenvatinib. Until recently, platinum rechallenge was often considered at the time of recurrence, given the lack of other available therapeutic options; however, "platinum sensitivity" in endometrial cancer is subjective and largely based on expert opinion and/or practitioner experience. Small retrospective studies have tried to provide guidance on the utility of platinum rechallenge, but they are limited by variable patient characteristics and small sample sizes. The applicability of these retrospective studies to contemporary clinical practice is difficult in the setting of changing patient demographics, a better understanding of endometrial cancer drivers, and the recent approvals of immune checkpoint inhibitors and the combination of lenvatinib plus pembrolizumab in the second-line setting. The primary focus of this review is to distill the available data regarding platinum-doublet chemotherapy rechallenge and highlight recent pivotal developments in endometrial cancer treatment, as well as future directions.

An Indirect Comparison of the Efficacy and Safety of Dostarlimab and Doxorubicin for the Treatment of Advanced and Recurrent Endometrial Cancer

BACKGROUND

There is no clear standard of care for advanced/recurrent endometrial cancer (EC) following platinum-based therapy. Dostarlimab is approved for patients with mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) advanced/recurrent EC. This indirect treatment comparison (ITC) assessed dostarlimab efficacy and safety from the single-arm GARNET (NCT02715284) trial compared with doxorubicin from ZoptEC (NCT01767155).

PATIENTS AND METHODS

Patient-level data and study variables from GARNET Cohort A1 (dMMR/MSI-H EC) and the ZoptEC doxorubicin control arm were merged. Patients were matched based on eligibility criteria (main analysis population). Safety population included all patients who received treatment. The primary efficacy comparison outcome, overall survival (OS), was calculated using a Cox proportional hazards model, with adjusted stabilized inverse probability of treatment weighting. Modified assessment-scheduled matching Kaplan--Meier analysis was used for progression-free survival (PFS) and time to deterioration (TTD) in quality of life (QoL).

RESULTS

In the main analysis population, median (95% CI) OS was not reached (NR; 18.0 months--NR) for dostarlimab (n = 92) and was 11.2 (10.0-13.1) months for doxorubicin (n = 233; HR: 0.41 [95% CI: 0.28-0.61]); median PFS was 12.2 (3.3-NR) and 4.9 (4.1-6.6) months, respectively. Median TTD in QoL was NR (2.5-NR; n = 61) and 4.5 (4.1-5.4; n = 188) months, respectively. Similar rates of adverse events (AEs, 11.6% vs 15.3%) and serious AEs (34.1% vs 30.1%) were observed with dostarlimab (n = 129) and doxorubicin (n = 249). Grade ≥3 AEs occurred in 48.1% vs 78.3%, respectively.

CONCLUSION

This ITC suggests a favorable benefit:risk profile for dostarlimab in patients with dMMR/MSI-H advanced/recurrent EC.

Previously treated recurrent or advanced endometrial cancer in England: A real-world observational analysis

OBJECTIVES

In patients with recurrent/advanced endometrial cancer who have progressed after first-line treatment, there are a lack of real-world data on treatment patterns, characteristics, and survival outcomes. A novel study was conducted to determine real-world treatment patterns and outcomes in England.

METHODS

This non-interventional study used routine, administrative health data from the National Cancer Registration and Analysis Service in England to identify patients diagnosed with recurrent/advanced endometrial cancer between 1 January 2013 and 31 December 2018, inclusive. A cohort of patients who progressed to second-line treatment were identified as the 'immune checkpoint inhibitor-eligible second-line' cohort. The co-primary objectives were to summarise baseline demographics, disease characteristics, treatments received, and depict overall survival and time-to-next-treatment (a proxy for progression-free survival) from the start of second-line therapy using Kaplan-Meier methodology.

RESULTS

Overall, 12,058 patients were diagnosed with recurrent/advanced endometrial cancer; 999 patients were included in the immune checkpoint inhibitor-eligible second-line cohort and 77.9% (778 of 999) had advanced disease (Stage III/IV). The most common treatments received at second-line were carboplatin plus paclitaxel (27.9%), carboplatin plus liposomal doxorubicin (14.1%), liposomal doxorubicin monotherapy (13.0%), and paclitaxel monotherapy (11.6%). From initiation of second-line therapy, median (95% confidence interval) overall survival was 10.3 months (9.2-11.1), and median time-to-next-treatment was 7.7 months (7.1-8.2).

CONCLUSIONS

Treatments received in the relapsed setting were variable and survival outcomes poor at second-line, highlighting the need for standard of care guidance and innovative therapies to improve patient outcomes in England and in countries with similar treatment patterns.

FUNDING

GSK.

Anlotinib in recurrent or metastatic endometrial cancer

OBJECTIVE

For recurrent or metastatic endometrial cancer after second-line treatment, therapeutic options are limited. Anlotinib is a new multi-targeted tyrosine kinase inhibitor of tumor angiogenesis and growth. The aim of this study was to explore the efficacy and safety of anlotinib in patients with recurrent or metastatic endometrial cancer.

METHODS

Patients with recurrent or metastatic endometrial cancer who received anlotinib or anlotinib plus pembrolizumab after second-line treatment between July 2017 and October 2020 were analyzed. Objective response rate, disease control rate, progression-free survival, overall survival, and safety were evaluated.

RESULTS

A total of 56 patients were analyzed. The median age was 62 years (range 42-80). The median treatment of anlotinib was 5.9 cycles (range 2-21). The overall objective response rate was 42.9%, and the disease control rate was 75%. 44 (78.6%) patients received anlotinib monotherapy and 12 (21.2%) patients received anlotinib plus pembrolizumab. The objective response rate was 40.9% versus 50% (p=0.52) and the disease control rate was 72.7% versus 83.3% (p=0.59) in the monotherapy group and the combination therapy group, respectively. The median progression-free survival and overall survival from initiation of anlotinib therapy was 6 months (95% CI 4.89 to 7.11) and 13.3 months (95% CI 9.94 to 16.61), respectively. On multivariable Cox analysis, age (>60 vs ≤60 years) was an independent impact factor for both progression-free survival and overall survival, while prior lines of treatment (2 lines vs ≥3 lines) was an independent predictor of progression-free survival. The incidences of grade 3/4 adverse events were hypertension (10.7%), fatigue (7.1%), hand-foot syndrome (7.1%), proteinuria (3.6%), sore throat (3.6%), and hypothyroidism (3.6%).

CONCLUSION

Anlotinib is effective and well tolerated in patients with recurrent or metastatic endometrial cancer. It may be considered a choice for patients younger than 60 years and who have had <3 lines of treatment.

Phase 2 Trial (POLA Study) of Lurbinectedin plus Olaparib in Patients with Advanced Solid Tumors: Results of Efficacy, Tolerability, and the Translational Study

Simple Summary

Genomic instability (GI) is a transversal phenomenon in oncology, constituting a hallmark of cancer. In gynecological malignancies, the predictive value of GI has been described and is mainly caused by alterations in the homologous recombination repair (HRR) genes, such as BRCA1/2. The POLA clinical trial constitutes an ideal substrate used to study the correlation between GI and response to combined therapy of lurbinectedin plus olaparib in solid tumors. In this context, we developed an approach based on next-generation sequencing, capable of shedding information about Copy Number Variations (CNV) as a surrogate of GI and genotyping of homologous recombination repair genes. Additionally, some algorithms used to extract GI parameters were tested and benchmarked, selecting the most informative mutational and GI features as potential predictive biomarkers for the drug combination explored in the POLA trial.

Abstract

We hypothesized that the combination of olaparib and lurbinectedin maximizes DNA damage, thus increasing its efficacy. The POLA phase 1 trial established the recommended phase 2 dose of lurbinectedin as being 1.5 mg (day 1) and that of olaparib as being 250 mg/12 h (days 1–5) for a 21-day cycle. In phase 2, we explore the efficacy of the combination in terms of clinical response and its correlation with mutations in the HRR genes and the genomic instability (GI) parameters. Results: A total of 73 patients with high-grade ovarian (n = 46), endometrial (n = 26), and triple-negative breast cancer (n = 1) were treated with lurbinectedin and olaparib. Most patients (62%) received ≥3 lines of prior therapy. The overall response rate (ORR) and disease control rate (DCR) were 9.6% and 72.6%, respectively. The median progression-free survival (PFS) was 4.54 months (95% CI 3.0–5.2). Twelve (16.4%) patients were considered long-term responders (LTR), with a median PFS of 13.3 months. No clinical benefit was observed for cases with HRR gene mutation. In ovarian LTRs, although a direct association with GI and a total loss of heterozygosity (LOH) events was observed, the association did not reach statistical significance (p = 0.055). Globally, the total number of LOHs might be associated with the ORR (p =0.074). The most common grade 3–4 toxicities were anemia and thrombocytopenia, in 6 (8.2%) and 3 (4.1%) patients, respectively. Conclusion: The POLA study provides evidence that the administration of lurbinectedin and olaparib is feasible and tolerable, with a DCR of 72.6%. Different GI parameters showed associations with better responses.

Lenvatinib plus Pembrolizumab for Advanced Endometrial Cancer

BACKGROUND

Standard therapy for advanced endometrial cancer after failure of platinum-based chemotherapy remains unclear.

METHODS

In this phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with advanced endometrial cancer who had previously received at least one platinum-based chemotherapy regimen to receive either lenvatinib (20 mg, administered orally once daily) plus pembrolizumab (200 mg, administered intravenously every 3 weeks) or chemotherapy of the treating physician's choice (doxorubicin at 60 mg per square meter of body-surface area, administered intravenously every 3 weeks, or paclitaxel at 80 mg per square meter, administered intravenously weekly [with a cycle of 3 weeks on and 1 week off]). The two primary end points were progression-free survival as assessed on blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1, and overall survival. The end points were evaluated in patients with mismatch repair-proficient (pMMR) disease and in all patients. Safety was also assessed.

RESULTS

A total of 827 patients (697 with pMMR disease and 130 with mismatch repair-deficient disease) were randomly assigned to receive lenvatinib plus pembrolizumab (411 patients) or chemotherapy (416 patients). The median progression-free survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 6.6 vs. 3.8 months; hazard ratio for progression or death, 0.60; 95% confidence interval [CI], 0.50 to 0.72; P<0.001; overall: 7.2 vs. 3.8 months; hazard ratio, 0.56; 95% CI, 0.47 to 0.66; P<0.001). The median overall survival was longer with lenvatinib plus pembrolizumab than with chemotherapy (pMMR population: 17.4 vs. 12.0 months; hazard ratio for death, 0.68; 95% CI, 0.56 to 0.84; P<0.001; overall: 18.3 vs. 11.4 months; hazard ratio, 0.62; 95% CI, 0.51 to 0.75; P<0.001). Adverse events of grade 3 or higher occurred in 88.9% of the patients who received lenvatinib plus pembrolizumab and in 72.7% of those who received chemotherapy.

CONCLUSIONS

Lenvatinib plus pembrolizumab led to significantly longer progression-free survival and overall survival than chemotherapy among patients with advanced endometrial cancer. (Funded by Eisai and Merck Sharp and Dohme [a subsidiary of Merck]; Study 309-KEYNOTE-775 ClinicalTrials.gov number, NCT03517449.).

Phase I study of lurbinectedin in combination with weekly paclitaxel with or without bevacizumab in patients with advanced solid tumors

Lurbinectedin and paclitaxel showed synergism in preclinical studies and have non-completely overlapping toxicity profiles. This phase I trial evaluated a combination of paclitaxel and lurbinectedin with/without bevacizumab in advanced tumors. This trial was divided into Group A, which evaluated weekly paclitaxel (60 or 80 mg) plus lurbinectedin (3.0-5.0 mg flat dose [FD] or 2.2 mg/m²) every 3 weeks in advanced solid tumors; and Group B, which evaluated bevacizumab (BEV, 15 mg/kg) added to the recommended dose (RD) defined in Group A in advanced epithelial ovarian or non-small cell lung cancer (NSCLC). 67 patients (A, n = 55; B, n = 12) were treated. The RD was paclitaxel 80 mg/m² on Day (D)1,D8 plus lurbinectedin 2.2 mg/m² on D1. At this RD, myelotoxicity was reversible and manageable, and most non-hematological toxicities were mild/moderate. Adding BEV did not notably change tolerability. Twenty-five confirmed responses were observed: 20/51 evaluable patients in Group A (overall response rate [ORR] = 39% at all dose levels and at the RD), and 5/10 evaluable patients in Group B (ORR = 50%). Most responders had breast (n = 7/12 patients), small cell lung (SCLC) (n = 5/7), epithelial ovarian (n = 3/9) and endometrial cancer (n = 3/11) in Group A, and epithelial ovarian (n = 3/4) and NSCLC (n = 2/6) in Group B. Clinical benefit rate was 61% in Group A (58% at the RD), and 90% in Group B. No major pharmacokinetic drug-drug interactions were observed. Paclitaxel/lurbinectedin and paclitaxel/lurbinectedin/BEV are feasible combinations. Further development is warranted of paclitaxel/lurbinectedin in SCLC, breast, and endometrial cancer, and of paclitaxel/lurbinectedin/BEV in epithelial ovarian cancer.

Pharmacological Treatment of Advanced, Persistent or Metastatic Endometrial Cancer: State of the Art and Perspectives of Clinical Research for the Special Issue "Diagnosis and Management of Endometrial Cancer"

Patients with metastatic or recurrent endometrial cancer (EC) not suitable for surgery and/or radiotherapy are candidates for pharmacological treatment frequently with unsatisfactory clinical outcomes. The purpose of this paper was to review the results obtained with chemotherapy, hormonal therapy, biological agents and immune checkpoint inhibitors in this clinical setting. The combination of carboplatin (CBDCA) + paclitaxel (PTX) is the standard first-line chemotherapy capable of achieving objective response rates (ORRs) of 43-62%, a median progression-free survival (PFS) of 5.3-15 months and a median overall survival (OS) of 13.2-37.0 months, respectively, whereas hormonal therapy is sometimes used in selected patients with slow-growing steroid receptor-positive EC. The combination of endocrine therapy with m-TOR inhibitors or cyclin-dependent kinase 4/6 inhibitors is currently under evaluation. Disappointing ORRs have been associated with epidermal growth factor receptor (EGFR) inhibitors, HER-2 inhibitors and multi-tyrosine kinase inhibitors used as single agents, and clinical trials evaluating the addition of bevacizumab to CBDCA + PTX have reported conflicting results. Immune checkpoint inhibitors, and especially pembrolizumab and dostarlimab, have achieved an objective response in 27-47% of highly pretreated patients with microsatellite instability-high (MSI-H)/mismatch repair (MMR)-deficient (-d) EC. In a recent study, the combination of lenvatinib + pembrolizumab produced a 24-week response rate of 38% in patients with highly pretreated EC, ranging from 64% in patients with MSI-H/MMR-d to 36% in those with microsatellite stable/MMR-proficient tumors. Four trials are currently investigating the addition of immune checkpoint inhibitors to PTX + CBDCA in primary advanced or recurrent EC, and two trials are comparing pembrolizumab + lenvatinib versus either CBDCA + PTX as a first-line treatment of advanced or recurrent EC or versus single-agent chemotherapy in advanced, recurrent or metastatic EC after one prior platinum-based chemotherapy.

Doxorubicin plus lurbinectedin in patients with advanced endometrial cancer: results from an expanded phase I study

Objective

Second-line treatment of endometrial cancer is an unmet medical need. We conducted a phase I study evaluating lurbinectedin and doxorubicin intravenously every 3 weeks in patients with solid tumors. The aim of this study was to characterise the efficacy and safety of lurbinectedin and doxorubicin for patients with endometrial cancer.

Methods

Thirty-four patients were treated: 15 patients in the escalation phase (doxorubicin 50 mg/m² and lurbinectedin 3.0–5.0 mg) and 19 patients in the expansion cohort (doxorubicin 40 mg/m² and lurbinectedin 2.0 mg/m²). All histological subtypes were eligible and patients had received one to two prior lines of chemotherapy for advanced disease. Antitumor activity was evaluated every two cycles according to the Response Evaluation Criteria in Solid Tumors version 1.1. Adverse events were graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.

Results

Median age (range) was 65 (51–78) years. Eastern Cooperative Oncology Group performance status was up to 1 in 97% of patients. In the escalation phase, 4 (26.7%) of 15 patients had confirmed response: two complete and two partial responses (95% CI 7.8% to 55.1%). Median duration of response was 19.5 months. Median progression-free survival was 7.3 (2.5 to 10.1) months. In the expansion cohort, confirmed partial response was reported in 8 (42.1%) of 19 patients (95% CI 20.3% to 66.5%). Median duration of response was 7.5 (6.4 to not reached) months, median progression-free survival was 7.7 (2.0 to 16.7) months and median overall survival was 14.2 (4.5 to not reached) months. Fatigue (26.3% of patients), and transient and reversible myelosuppression (neutropenia, 78.9%; febrile neutropenia, 21.1%; thrombocytopenia, 15.8%) were the main grade 3 and higher toxicities in the expanded cohort.

Conclusions

In patients with recurrent advanced endometrial cancer treated with doxorubicin and lurbinectedin, response rates (42%) and duration of response (7.5 months) were favorable. Further evaluation of doxorubicin and lurbinectedin is warranted in this patient population.

Metabolomic Identification of Anticancer Metabolites of Australian Propolis and Proteomic Elucidation of Its Synergistic Mechanisms with Doxorubicin in the MCF7 Cells

The combination of natural products with standard chemotherapeutic agents offers a promising strategy to enhance the efficacy or reduce the side effects of standard chemotherapy. Doxorubicin (DOX), a standard drug for breast cancer, has several disadvantages, including severe side effects and the development of drug resistance. Recently, we reported the potential bioactive markers of Australian propolis extract (AP-1) and their broad spectrum of pharmacological activities. In the present study, we explored the synergistic interactions between AP-1 and DOX in the MCF7 breast adenocarcinoma cells using different synergy quantitation models. Biochemometric and metabolomics-driven analysis was performed to identify the potential anticancer metabolites in AP-1. The molecular mechanisms of synergy were studied by analysing the apoptotic profile via flow cytometry, apoptotic proteome array and measuring the oxidative status of the MCF7 cells treated with the most synergistic combination. Furthermore, label-free quantification proteomics analysis was performed to decipher the underlying synergistic mechanisms. Five prenylated stilbenes were identified as the key metabolites in the most active AP-1 fraction. Strong synergy was observed when AP-1 was combined with DOX in the ratio of 100:0.29 (w/w) as validated by different synergy quantitation models implemented. AP-1 significantly enhanced the inhibitory effect of DOX against MCF7 cell proliferation in a dose-dependent manner with significant inhibition of the reactive oxygen species (p < 0.0001) compared to DOX alone. AP-1 enabled the reversal of DOX-mediated necrosis to programmed cell death, which may be advantageous to decline DOX-related side effects. AP-1 also significantly enhanced the apoptotic effect of DOX after 24 h of treatment with significant upregulation of catalase, HTRA2/Omi, FADD together with DR5 and DR4 TRAIL-mediated apoptosis (p < 0.05), contributing to the antiproliferative activity of AP-1. Significant upregulation of pro-apoptotic p27, PON2 and catalase with downregulated anti-apoptotic XIAP, HSP60 and HIF-1α, and increased antioxidant proteins (catalase and PON2) may be associated with the improved apoptosis and oxidative status of the synergistic combination-treated MCF7 cells compared to the mono treatments. Shotgun proteomics identified 21 significantly dysregulated proteins in the synergistic combination-treated cells versus the mono treatments. These proteins were involved in the TP53/ATM-regulated non-homologous end-joining pathway and double-strand breaks repairs, recruiting the overexpressed BRCA1 and suppressed RIF1 encoded proteins. The overexpression of UPF2 was noticed in the synergistic combination treatment, which could assist in overcoming doxorubicin resistance-associated long non-coding RNA and metastasis of the MCF7 cells. In conclusion, we identified the significant synergy and highlighted the key molecular pathways in the interaction between AP-1 and DOX in the MCF7 cells together with the AP-1 anticancer metabolites. Further in vivo and clinical studies are warranted on this synergistic combination.

Real-world database analysis of the characteristics and treatment patterns of patients with endometrial cancer in Japan

OBJECTIVE

The aim was to identify the characteristics and treatment patterns of early and advanced stage endometrial cancer patients using real-world data.

METHODS

Patients' data extracted from a Japanese health insurance claims database were analyzed.

RESULTS

Of the 12,449 endometrial cancer patients, 74.4% were in stage I, 5.1% in stage II, 12.0% in stage III, and 8.4% in stage IV. Their median age was 60.5 years, higher in advanced stages (III/IV) than in early stages (I/II). Overall, 11,055 patients (88.8%) underwent surgery, and 4977 patients (40.0%) received post-surgery treatment, including chemotherapy (4441: 35.7%), chemoradiation therapy (379: 3.0%), and radiation therapy (157 patients: 1.3%); 1394 patients (11.2%) were not treated by surgery, and 742 patients (6.0%) received other treatment, with chemotherapy (548: 4.4%), radiation therapy (105: 0.8%), and chemoradiation therapy (89: 0.7%). The rate of patients undergoing surgery decreased, and that receiving chemotherapy increased significantly as cancer stage progressed. Paclitaxel/carboplatin was the most frequent first-line regimen (85.4% of patients), whereas various combination and monotherapy regimens were used as second- and third-line regimens. The most frequent second-line monotherapy was paclitaxel. The rate of monotherapy increased as the treatment line progressed (first-line 3.5%, second-line 22.0%, and third-line 36.4%).

CONCLUSIONS

The characteristics and treatment patterns of endometrial cancer patients differed between early and advanced stages, as did the chemotherapy regimens among first-, second-, and third-lines. Since various regimens were used for second- and third-line chemotherapies, development of appropriate second- and third-line chemotherapy regimens is warranted. A real-world analysis of cancer patients using a nationwide claims database may be a valuable approach to identifying unmet medical needs.

Immunotherapy in endometrial cancer: rationale, practice and perspectives

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

Endometrial Carcinoma: Immune Microenvironment and Emerging Treatments in Immuno-Oncology

Endometrial cancer (EC) can easily be cured when diagnosed at an early stage. However, advanced and metastatic EC is a common disease, affecting more than 15,000 patients per year in the United Sates. Only limited treatment options were available until recently, with a taxane–platinum combination as the gold standard in first-line setting and no efficient second-line chemotherapy or hormone therapy. EC can be split into four molecular subtypes, including hypermutated cases with POLE mutations and 25–30% harboring a microsatellite instability (MSI) phenotype with mismatch repair deficiency (dMMR). These tumors display a high load of frameshift mutations, leading to increased expression of neoantigens that can be targeted by the immune system, including (but not limited) to T-cell response. Recent data have demonstrated this impact of programmed death 1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors on chemo-resistant metastatic EC. The uncontrolled KEYNOTE-158 and GARNET trials have shown high response rates with pembrolizumab and dostarlimab in chemoresistant MSI-high tumors. Most responders experiment long responses that last more than one year. Similar, encouraging results were obtained for MMR proficient (MMRp) cases treated with a combination of pembrolizumab and the angiogenesis inhibitor lenvatinib. Approvals have, thus, been obtained or are underway for EC with immune checkpoint inhibitors (ICI) used as monotherapy, and in combination with antiangiogenic agents. Combinations with other targeted therapies are under evaluation and randomized studies are ongoing to explore the impact of ICI-chemotherapy triplets in first-line setting. We summarize in this review the current knowledge of the immune environment of EC, both for MMRd and MMRp tumors. We also detail the main clinical data regarding PD-1/PD-L1 inhibitors and discuss the next steps of development for immunotherapy, including various ICI-based combinations planned to limit resistance to immunotherapy.

A Microfluidic Multisize Spheroid Array for Multiparametric Screening of Anticancer Drugs and Blood-Brain Barrier Transport Properties

Physiological-relevant in vitro tissue models with their promise of better predictability have the potential to improve drug screening outcomes in preclinical studies. Despite the advances of spheroid models in pharmaceutical screening applications, variations in spheroid size and consequential altered cell responses often lead to nonreproducible and unpredictable results. Here, a microfluidic multisize spheroid array is established and characterized using liver, lung, colon, and skin cells as well as a triple-culture model of the blood-brain barrier (BBB) to assess the effects of spheroid size on (a) anticancer drug toxicity and (b) compound penetration across an advanced BBB model. The reproducible on-chip generation of 360 spheroids of five dimensions on a well-plate format using an integrated microlens technology is demonstrated. While spheroid size-related IC50 values vary up to 160% using the anticancer drugs cisplatin (CIS) or doxorubicin (DOX), reduced CIS:DOX drug dose combinations eliminate all lung microtumors independent of their sizes. A further application includes optimizing cell seeding ratios and size-dependent compound uptake studies in a perfused BBB model. Generally, smaller BBB-spheroids reveal an 80% higher compound penetration than larger spheroids while verifying the BBB opening effect of mannitol and a spheroid size-related modulation on paracellular transport properties.

Multifunctional nanoplatforms co-delivering combinatorial dual-drug for eliminating cancer multidrug resistance

Clinically, the primary cause of chemotherapy failure belongs to the occurrence of cancer multidrug resistance (MDR), which directly leads to the recurrence and metastasis of cancer along with high mortality. More and more attention has been paid to multifunctional nanoplatform-based dual-therapeutic combination to eliminate resistant cancers. In addition to helping both cargoes improve hydrophobicity and pharmacokinetic properties, increase bioavailability, release on demand and enhance therapeutic efficacy with low toxic effects, these smart co-delivery nanocarriers can even overcome drug resistance. Here, this review will not only present different types of co-delivery nanocarriers, but also summarize targeted and stimuli-responsive combination nanomedicines. Furthermore, we will focus on the recent progress in the co-delivery of dual-drug using such intelligent nanocarriers for surmounting cancer MDR. Whereas it remains to be seriously considered that there are some knotty issues in the fight against MDR of cancers via using co-delivery nanoplatforms, including limited intratumoral retention, the possible changes of combinatorial ratio under complex biological environments, drug release sequence from the nanocarriers, and subsequent free-drug resistance after detachment from the nanocarriers. It is hoped that, with the advantage of continuously developing nanomaterials, two personalized therapeutic agents in combination can be better exploited to achieve the goal of cooperatively combating cancer MDR, thus advancing the time to clinical transformation.

Cost-effectiveness of pembrolizumab compared with chemotherapy in the US for women with previously treated deficient mismatch repair or high microsatellite instability unresectable or metastatic endometrial cancer

AIMS

There is limited published evidence for the cost-effectiveness of treatments for unresectable or metastatic endometrial cancer (mEC). The objective of this analysis was to assess the cost-effectiveness of pembrolizumab versus chemotherapy for previously treated unresectable or mEC, in women whose tumors have deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H). The analysis was carried out from a US healthcare payer perspective.

MATERIALS AND METHODS

A lifetime partitioned survival model comprising three health states (progression-free, progressed disease and death) was constructed. Chemotherapy was represented by single-agent paclitaxel or doxorubicin. Overall survival, progression-free survival and time on treatment data for pembrolizumab were obtained from a Phase II clinical study that included women with previously treated dMMR/MSI-H unresectable or mEC (KEYNOTE-158, NCT02628067). Survival data for chemotherapy were obtained from a published Phase III study for previously treated advanced endometrial cancer. Costs included were drug acquisition and administration, health-state, end-of-life, and adverse event management. Costs were presented in 2019 US$. Outcomes were calculated as quality-adjusted life-years (QALYs), using EQ-5D data from KEYNOTE-158. Model results were tested extensively in deterministic and probabilistic sensitivity analyses.

RESULTS

Results demonstrated that pembrolizumab is a highly cost-effective treatment option when compared with chemotherapy, with estimated deterministic and probabilistic incremental cost-effectiveness ratios (ICERs) of $58,165 and $57,668 per QALY gained, respectively. Pembrolizumab was associated with a large QALY and life-year gain per person versus chemotherapy over the model time horizon (deterministic 4.68 life year gain, 3.80 QALYs), with the majority of QALYs accrued in the progression-free health state.

LIMITATIONS

The key limitation of the analysis was the lack of comparative effectiveness data for pembrolizumab versus chemotherapy.

CONCLUSIONS

Pembrolizumab is a highly cost-effective treatment option when compared with chemotherapy for women with previously treated dMMR/MSI-H unresectable or mEC. Results were robust to the changes in parameters and assumptions explored.

New Trends for Antimalarial Drugs: Synergism between Antineoplastics and Antimalarials on Breast Cancer Cells

Chemotherapy plays a key role in breast cancer therapy, but drug resistance and unwanted side effects make the treatment less effective. We propose a new combination model that combines antineoplastic drugs and antimalarials for breast cancer therapy. Cytotoxic effects of two antineoplastic agents alone and in combination with several antimalarials on MCF-7 tumor cell line was evaluated. Different concentrations in a fixed ratio were added to the cultured cells and incubated for 48 h. Cell viability was evaluated using MTT and SRB assays. Synergism was evaluated using the Chou-Talalay method. The results indicate doxorubicin (DOX) and paclitaxel (PTX) alone at concentrations of their IC₅₀ and higher are cell growth inhibitors. Mefloquine, artesunate, and chloroquine at concentrations of their IC₅₀ demonstrate anti-cancer activity. In combination, almost all antimalarials demonstrate higher ability than DOX and PTX alone to decrease cell viability at concentrations of IC₅₀ and lower than their IC₅₀. The combination of chloroquine, artesunate and mefloquine with DOX and PTX was synergic (CI < 1). The combination of DOX and mefloquine after 48 h incubation demonstrated the highest cytotoxicity against MCF-7 cells, and the combination of DOX and artesunate was the most synergic. These results suggest antimalarials could act synergistically with DOX/PTX for breast cancer therapy.

[Nice-Saint-Paul de Vence 2020 recommendations for clinical practice: Management of metastatic and/or relapsing endometrial cancer]

Endometrial cancer is a common cancer in older women and is often associated with comorbidities. Management of metastatic disease and/or relapse requires a multidisciplinary approach. Recent advances in the understanding of oncogenesis and molecular classification of endometrial cancers offer new therapeutic perspectives. These first recommendations, established following the methodology of Nice-Saint-Paul recommendations for clinical practice (RPC), aims to integrate molecular advances in diagnostic and therapeutic management. In 2020, the histological diagnosis of endometrial cancer is based on morphology and immunohistochemistry, including at least p53, oestrogen and progesterone receptors. Deficiency in the DNA mismatch repair system (MMR) must be assessed in all advanced endometrial tumors for oncogenetic and theranostic purposes. It can be sought initially by an analysis in immunohistochemistry with the 4 markers (MLH1, MSH2, MSH6, PMS2). Medical treatment depends on histological type, presence of hormone receptors and patient's profile to refer to chemotherapy (carboplatin-paclitaxel) or hormone therapy (for example of the progestogen type); in the event of MMR-deficiency, immunotherapy trial is the best option. As part of overall management of advanced endometrial cancer, radiotherapy (and surgery in rare cases) must be discussed, in particular in the event of loco-regional only relapse or oligometastatic disease.

Lenvatinib Plus Pembrolizumab in Patients With Advanced Endometrial Cancer

PURPOSE

Patients with advanced endometrial carcinoma have limited treatment options. We report final primary efficacy analysis results for a patient cohort with advanced endometrial carcinoma receiving lenvatinib plus pembrolizumab in an ongoing phase Ib/II study of selected solid tumors.

METHODS

Patients took lenvatinib 20 mg once daily orally plus pembrolizumab 200 mg intravenously once every 3 weeks, in 3-week cycles. The primary end point was objective response rate (ORR) at 24 weeks (ORRWk24); secondary efficacy end points included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Tumor assessments were evaluated by investigators per immune-related RECIST.

RESULTS

At data cutoff, 108 patients with previously treated endometrial carcinoma were enrolled, with a median follow-up of 18.7 months. The ORRWk24 was 38.0% (95% CI, 28.8% to 47.8%). Among subgroups, the ORRWk24 (95% CI) was 63.6% (30.8% to 89.1%) in patients with microsatellite instability (MSI)-high tumors (n = 11) and 36.2% (26.5% to 46.7%) in patients with microsatellite-stable tumors (n = 94). For previously treated patients, regardless of tumor MSI status, the median DOR was 21.2 months (95% CI, 7.6 months to not estimable), median PFS was 7.4 months (95% CI, 5.3 to 8.7 months), and median OS was 16.7 months (15.0 months to not estimable). Grade 3 or 4 treatment-related adverse events occurred in 83/124 (66.9%) patients.

CONCLUSION

Lenvatinib plus pembrolizumab showed promising antitumor activity in patients with advanced endometrial carcinoma who have experienced disease progression after prior systemic therapy, regardless of tumor MSI status. The combination therapy had a manageable toxicity profile.

Intrinsic and Extrinsic Factors Affecting Microtubule Dynamics in Normal and Cancer Cells

Microtubules (MTs), highly dynamic structures composed of α- and β-tubulin heterodimers, are involved in cell movement and intracellular traffic and are essential for cell division. Within the cell, MTs are not uniform as they can be composed of different tubulin isotypes that are post-translationally modified and interact with different microtubule-associated proteins (MAPs). These diverse intrinsic factors influence the dynamics of MTs. Extrinsic factors such as microtubule-targeting agents (MTAs) can also affect MT dynamics. MTAs can be divided into two main categories: microtubule-stabilizing agents (MSAs) and microtubule-destabilizing agents (MDAs). Thus, the MT skeleton is an important target for anticancer therapy. This review discusses factors that determine the microtubule dynamics in normal and cancer cells and describes microtubule–MTA interactions, highlighting the importance of tubulin isoform diversity and post-translational modifications in MTA responses and the consequences of such a phenomenon, including drug resistance development.

Microtubule-targeting agents and their impact on cancer treatment

Microtubule-targeting agents (MTAs) constitute a diverse group of chemical compounds that bind to microtubules and affect their properties and function. Disruption of microtubules induces various cellular responses often leading to cell cycle arrest or cell death, the most common effect of MTAs. MTAs have found a plethora of practical applications in weed control, as fungicides and antiparasitics, and particularly in cancer treatment. Here we summarize the current knowledge of MTAs, the mechanisms of action and their role in cancer treatment. We further outline the potential use of MTAs in anti-metastatic therapy based on inhibition of cancer cell migration and invasiveness. The two main problems associated with cancer therapy by MTAs are high systemic toxicity and development of resistance. Toxic side effects of MTAs can be, at least partly, eliminated by conjugation of the drugs with various carriers. Moreover, some of the novel MTAs overcome the resistance mediated by both multidrug resistance transporters as well as overexpression of specific β-tubulin types. In anti-metastatic therapy, MTAs should be combined with other drugs to target all modes of cancer cell invasion.

Phase II Trial of Cabozantinib in Recurrent/Metastatic Endometrial Cancer: A Study of the Princess Margaret, Chicago, and California Consortia (NCI9322/PHL86)

PURPOSE

The relevance of the MET/hepatocyte growth factor pathway in endometrial cancer tumor biology supports the clinical evaluation of cabozantinib in this disease.

PATIENTS AND METHODS

PHL86/NCI#9322 (NCT01935934) is a single arm study that evaluated cabozantinib (60 mg once daily) in women with endometrial cancer with progression after chemotherapy. Coprimary endpoints were response rate and 12-week progression-free-survival (PFS). Patients with uncommon histology endometrial cancer (eg, carcinosarcoma and clear cell) were enrolled in a parallel exploratory cohort.

RESULTS

A total of 102 patients were accrued. Among 36 endometrioid histology patients, response rate was 14%, 12-week PFS rate was 67%, and median PFS was 4.8 months. In serous cohort of 34 patients, response rate was 12%, 12-week PFS was 56%, and median PFS was 4.0 months. In a separate cohort of 32 patients with uncommon histology endometrial cancer (including carcinosarcoma), response rate was 6% and 12-week PFS was 47%. Six patients were on treatment for >12 months, including two for >30 months. Common cabozantinib-related toxicities (>30% patients) included hypertension, fatigue, diarrhea, nausea, and hand-foot syndrome. Gastrointestinal fistula/perforation occurred in four of 70 (6%) patients with serous/endometrioid cancer and five of 32 (16%) patients in exploratory cohort. We observed increased frequency of responses with somatic CTNNB1 mutation [four partial responses (PRs) in 10 patients, median PFS 7.6 months] and concurrent KRAS and PTEN/PIK3CA mutations (three PRs in 12 patients, median PFS 5.9 months).

CONCLUSIONS

Cabozantinib has activity in serous and endometrioid histology endometrial cancer. These results support further evaluation in genomically characterized patient cohorts.

Second-line lenvatinib in patients with recurrent endometrial cancer

OBJECTIVE

This study assessed the efficacy of lenvatinib, a multitargeted tyrosine kinase inhibitor, as second-line therapy in patients with unresectable endometrial cancer. The primary end point was the objective response rate (ORR) as assessed by independent radiologic review (IRR). Secondary end points included median progression-free survival (PFS), overall survival (OS), and clinical benefit rate. Exploratory end points examined the association of baseline levels of plasma biomarkers (50 circulating cytokine and/or angiogenic factors measured by immunoassays) with efficacy outcomes.

METHODS

An international, open-label, single-arm, multicenter, phase 2 trial was conducted. Eligible patients had histologically confirmed unresectable endometrial cancer that relapsed after 1 prior systemic platinum-based chemotherapy. Patients received once-daily oral lenvatinib 24 mg in a 28-day dosing cycle.

RESULTS

There were 133 patients in the study. By IRR, 19 patients had a confirmed objective response for an ORR of 14.3% (95% CI: 8.8-21.4). Durable stable disease (≥23 weeks) was observed in 31 patients (23.3%) and the clinical benefit rate was 37.6% (95% CI: 29.3-46.4). Median PFS was 5.6 months (95% CI: 3.7-6.3), and median OS was 10.6 months (95% CI: 8.9-14.9). The most common (any grade) treatment-related adverse events were fatigue/asthenia (48%), hypertension (49%), nausea/vomiting (32%), decreased appetite (32%), and diarrhea (31%). Lower baseline levels of angiopoietin-2 were associated with longer PFS, OS, and a higher ORR.

CONCLUSIONS

Patients with recurrent endometrial cancer treated with second-line lenvatinib experienced modest antitumor activity and treatment was generally well tolerated, with a safety profile consistent with previous studies.

E-Jet 3D-Printed Scaffolds as Sustained Multi-Drug Delivery Vehicles in Breast Cancer Therapy

PURPOSE

Combination chemotherapy is gradually receiving more attention because of its potential synergistic effect and reduced drug doses in clinical application. However, how to precisely control drug release dose and time using vehicles remains a challenge. This work developed an efficient drug delivery system to combat breast cancer, which can enhance drug effects despite reducing its concentration.

METHODS

Controlled-release poly-lactic-co-glycolic acid (PLGA) scaffolds were fabricated by E-jet 3D printing to deliver doxorubicin (DOX) and cisplatin (CDDP) simultaneously.

RESULTS

This drug delivery system allowed the use of a reduced drug dosage resulting in a better effect on the human breast cancer cell apoptosis and inhibiting tumor growth, compared with the effect of each drug and the two drugs administrated without PLGA scaffolds. Our study suggested that DOX-CDDP-PLGA scaffolds could efficiently destroy MDA-MB-231 cells and restrain tumor growth.

CONCLUSIONS

The 3D printed PLGA scaffolds with their time-programmed drug release might be useful as a new multi-drug delivery vehicle in cancer therapy, which has a potential advantage in a long term tumor cure and prevention of tumor recurrence.

Current recommendations and recent progress in endometrial cancer

Endometrial cancer is the most common gynecologic cancer in the United States, and its incidence is rising. Although there have been significant recent advances in our understanding of endometrial cancer biology, many aspects of treatment remain mired in controversy, including the role of surgical lymph node assessment and the selection of patients for adjuvant radiation or chemotherapy. For the subset of women with microsatellite-instable, metastatic disease, anti- programmed cell death protein 1 immunotherapy (pembrolizumab) is now approved by the US Food and Drug Administration, and numerous trials are attempting to build on this early success.

Comprehensive genomic profiling of recurrent endometrial cancer: Implications for selection of systemic therapy

OBJECTIVES

To assess whether comprehensive genomic profiling (CGP) in the setting of routine clinical care allows molecular classification of recurrent endometrial cancer (EC) into the four Cancer Genome Atlas (TCGA) categories: POLE ultramutated, microsatellite instable, copy-number low, and copy-number high and whether this approach can identify genomic alterations (GAs) which inform treatment decisions.

METHODS

Archival tissues from 74 patients diagnosed with recurrent EC were prospectively analyzed using hybrid-capture-based genomic profiling. Tumor mutational burden and microsatellite instability were measured. Clinically relevant GAs (CRGAs) were defined as GAs associated with targeted therapies available on-label or in mechanism-driven clinical trials.

RESULTS

Using POLE mutational analysis, mismatch repair status, and p53 mutational analysis as surrogate for 'copy-number' status CGP segregated all cases into four TCGA molecular subgroups. While recurrent serous ECs were predominantly copy-number high, we found no clear prevalence of a specific molecular subtype in endometrioid, clear cell or undifferentiated tumors. Every tumor sample had at least one GA and 91% (67/74) had at least one CRGA. In this series 32% (24/74) of patients received a matched therapy based on the results of CGP. Objective responses to the matched therapy were seen in 25% (6/24) of patients with an additional 37.5% (9/24) achieving stable disease leading to a clinical benefit rate of 62.5% with a median treatment duration of 14.6 months (range 4.3-69 months).

CONCLUSIONS

CGP allows molecular classification of EC into four TCGA categories and allows identification of potential biomarkers for matched therapy in the setting of routine clinical care.

Lenvatinib plus pembrolizumab in patients with advanced endometrial cancer: an interim analysis of a multicentre, open-label, single-arm, phase 2 trial

BACKGROUND

Lenvatinib is a multikinase inhibitor of VEGFR1, VEGFR2, and VEGFR3, and other receptor tyrosine kinases. Pembrolizumab, an antibody targeting PD-1, has moderate efficacy in biomarker-unselected endometrial cancer. We aimed to assess the combination of lenvatinib plus pembrolizumab in patients with advanced endometrial carcinoma, after establishing the maximum tolerated dose in a phase 1b study.

METHODS

In this open-label, single-arm, phase 2 study done at 11 centres in the USA, eligible patients were aged 18 years or older and had metastatic endometrial cancer (unselected for microsatellite instability or PD-L1), had an Eastern Cooperative Oncology Group performance status of 0 or 1, had received no more than two previous systemic therapies, had measurable disease according to the immune-related Response Evaluation Criteria In Solid Tumors (irRECIST), and had a life expectancy of 12 weeks or longer. Patients received 20 mg oral lenvatinib daily plus 200 mg intravenous pembrolizumab every 3 weeks. Treatment continued until disease progression, development of unacceptable toxic effects, or withdrawal of consent. The primary endpoint of this interim analysis was the proportion of patients with an objective response at week 24 as assessed by investigators according to irRECIST in the per-protocol population. This trial is registered with ClinicalTrials.gov, number NCT02501096.

FINDINGS

Between Sept 10, 2015, and July 24, 2017, 54 patients were enrolled, 53 of whom were included in the analysis. At the cutoff date for anti-tumour activity data (Dec 15, 2017), median study follow-up was 13·3 months (IQR 6·7-20·1). 21 (39·6% [95% CI 26·5-54·0]) patients had an objective response at week 24. Serious treatment-related adverse events occurred in 16 (30%) patients, and one treatment-related death was reported (intracranial haemorrhage). The most frequently reported any-grade treatment-related adverse events were hypertension (31 [58%]), fatigue (29 [55%]), diarrhoea (27 [51%]), and hypothyroidism (25 [47%]). The most common grade 3 treatment-related adverse events were hypertension (18 [34%]) and diarrhoea (four [8%]). No grade 4 treatment-related adverse events were reported. Five (9%) patients discontinued study treatment because of treatment-related adverse events.

INTERPRETATION

Lenvatinib plus pembrolizumab showed anti-tumour activity in patients with advanced recurrent endometrial cancer with a safety profile that was similar to those previously reported for lenvatinib and pembrolizumab monotherapies, apart from an increased frequency of hypothyroidism. Lenvatinib plus pembrolizumab could represent a new potential treatment option for this patient population, and is being investigated in a randomised phase 3 study.

FUNDING

Eisai and Merck.

A phase II study of frontline paclitaxel/carboplatin/bevacizumab, paclitaxel/carboplatin/temsirolimus, or ixabepilone/carboplatin/bevacizumab in advanced/recurrent endometrial cancer

OBJECTIVE

Paclitaxel and carboplatin (PC) is a standard initial therapy for advanced endometrial cancer. We evaluated the efficacy and tolerability of incorporating three novel agents into initial therapy.

METHODS

In this randomized phase II trial, patients with chemotherapy-naïve stage III/IVA (with measurable disease) and stage IVB or recurrent (with or without measurable disease) endometrial cancer were randomly assigned to treatment with PC plus bevacizumab (Arm 1), PC plus temsirolimus (Arm 2) or ixabepilone and carboplatin (IC) plus bevacizumab (Arm 3). The primary endpoint was progression-free survival (PFS). Comparable patients on the PC Arm of trial GOG209 were used as historical controls. Secondary endpoints were response rate, overall survival (OS), and safety.

RESULTS

Overall, 349 patients were randomized. PFS duration was not significantly increased in any experimental arm compared with historical controls (p > 0.039). Treatment HRs (92% CI) for Arms 1, 2, and 3 relative to controls were 0.81 (0.63-1.02), 1.22 (0.96-1.55) and 0.87 (0.68-1.11), respectively. Response rates were similar across arms (60%, 55% and 53%, respectively). Relative to controls, OS duration (with censoring at 36 months), was significantly increased in Arm 1 (p < 0.039) but not in Arms 2 and 3; the HRs (92% CIs) were 0.71 (0.55-0.91), 0.99 (0.78-1.26), and 0.97 (0.77-1.23), respectively. No new safety signals were identified. Common mutations and rates of mismatch repair protein loss are described by histotype. Potential predictive biomarkers for temsirolimus and bevacizumab were identified.

CONCLUSION

PFS was not significantly increased in any experimental arm compared to historical controls. NRG Oncology/Gynecologic Oncology Group Study GOG-86P.

Management Strategies for Recurrent Endometrial Cancer

INTRODUCTION

Endometrial cancer is the most common gynecologic malignancy in the developed world, and its incidence is increasing. Mortality from this cancer has not improved in recent decades and is primarily driven by high-grade carcinomas that are more likely to present at an advanced stage and ultimately are more likely to recur. The prognosis for recurrent endometrial cancer is poor, especially for the 50% of these women that present with extrapelvic disease recurrence. As a standard of care, recurrent disease has been treated with platinum-based chemotherapy; however, new therapies are emerging as we identify drivers of proliferation and metastasis at the cellular and molecular levels. Areas Covered: We review currently available data for the management of recurrent endometrial cancer, with a focus on systemic treatment of recurrent disease. We discuss the available evidence for first-line, second-line, and subsequent systemic therapy and discuss emerging therapeutic targets including their biologic plausibility and early clinical data. Expert Commentary: Endometrial cancer, though prevalent, remains underfunded and understudied. Recurrent and metastatic disease remains difficult to treat, and prospective randomized data are limited. Our ability to reduce mortality due to this cancer is dependent on identifying new and effective therapeutic strategies for recurrent disease.

Synthesis & antitumor activity of epothilones B and D and their analogs

Epothilone is a newly developed antitumor drug; its antitumor principle is to stop the cell cycle by binding to tubulin in tumor cells, promoting tubulin polymerization, inhibiting depolymerization of microtubules, and ultimately inducing apoptosis. There are many analogs of epothilone, such as epothilone B, epothilone D, ixabepilone, sagopilone, 21-amino-epothilone B and KOS-1584. Herein, the synthesis and antitumor activity of epothilones B and D were summed up. The antitumor activity of epothilone analogs was also compared. Synthesis of epothilone and its analogs is more complex, and choosing the proper synthetic method is very important. Moreover, these compounds have obvious antitumor effect. The epothilone and its analogs will continue to play an important role in the future treatment of tumors.

Endometrial cancer: Molecular markers and management of advanced stage disease

Endometrial cancer is the most prevalent gynecologic cancer in the United States. Over the last 10 years, death rates from endometrial cancer have been rising about 1.4% per year. Traditionally endometrial cancer treatment has been driven by stage and histology. Recent studies have, however, shown that cancers of the same stage and histology have very distinct molecular and genomic profiles. Translational research is progressing rapidly and endometrial cancer-specific precision medicine is evolving. The first tissue agnostic therapy based on the molecular profile of the tumor was approved by the FDA this year. The approval of immune checkpoint inhibitor, pembrolizumab (anti-PD-1), for all solid tumors with defective DNA mismatch repair, could benefit 20-30% of patients with advanced endometrial cancer. Other genomic changes and molecular markers in endometrial cancer, such as hormone receptor status, could lead to more tailored therapy in the future. Pre-clinical and clinical investigations of targeted therapies suggest efficacy for some agents. Single agent targeted therapies, however, have modest activity. Identifying biomarkers that effectively determine response to targeted therapy remains a challenge. The next generation of clinical trials will focus on novel combinations and how to best utilize the advances that have been made in sequencing technology and bioinformatics. Although there is currently an immense body of data and many options for obtaining genomic characteristics of endometrial cancer, how to interpret and utilize this data is still being explored. This review will summarize the important trials that have led to the treatment options we have for advanced and/or recurrent endometrial cancer and discuss the important studies that have led to a better understanding of the distinctive molecular and genomic profiles within endometrial cancer. We will review the current status of biomarker-driven targeted therapy in endometrial cancer and the rationale behind ongoing clinical trials that are utilizing novel targeted agents.

AXL modulates extracellular matrix protein expression and is essential for invasion and metastasis in endometrial cancer

The receptor tyrosine kinase AXL promotes migration, invasion, and metastasis. Here, we evaluated the role of AXL in endometrial cancer. High immunohistochemical expression of AXL was found in 76% (63/83) of advanced-stage, and 77% (82/107) of high-grade specimens and correlated with worse survival in uterine serous cancer patients. In vitro, genetic silencing of AXL inhibited migration and invasion but had no effect on proliferation of ARK1 endometrial cancer cells. AXL-deficient cells showed significantly decreased expression of phospho-AKT as well as uPA, MMP-1, MMP-2, MMP-3, and MMP-9. In a xenograft model of human uterine serous carcinoma with AXL-deficient ARK1 cells, there was significantly less tumor burden than xenografts with control ARK1 cells. Together, these findings underscore the therapeutic potentials of AXL as a candidate target for treatment of metastatic endometrial cancer.

Moving forward with actionable therapeutic targets and opportunities in endometrial cancer: A NCI clinical trials planning meeting report

The incidence of endometrial cancer (EC) in the U.S. has been rising, from an estimated annual incidence of 49,560 in 2013 to 61,380 in 2017. Meanwhile, the SEER-based relative survival of women with EC in the U.S. has remained flat [82.3% from 1987 to 1989, 82.8% from 2007 to 2013] and our recent increased understanding of EC biology and subtypes has not been translated into therapeutic advances. The U.S. National Cancer Institute (NCI) therefore convened a Uterine Clinical Trials Planning Meeting in January 2016 to initiate and accelerate design of molecularly-targeted EC trials. Prior to the meeting a group of experts in this field summarized available data, emphasizing data on human samples, to identify potentially actionable alterations in EC, and the results of their work has been separately published. The Clinical Trials Meeting planners focused on discussion of (1) novel trial designs, including window-of opportunity trials and appropriate control groups for randomized trials, (2) targets specific to serous carcinoma and promises and pitfalls of separate trials for women with tumors of this histology (3) specific recommendations for future randomized trials.

Dual Chemodrug-Loaded Single-Walled Carbon Nanohorns for Multimodal Imaging-Guided Chemo-Photothermal Therapy of Tumors and Lung Metastases

Tumor combination therapy using nano formulations with multimodal synergistic therapeutic effects shows great potential for complete ablation of tumors. However, targeting tumor metastases with nano structures is a major obstacle for therapy. Therefore, developing a combination therapy system able to target both primary tumors and their metastases at distant sites with synergistic therapy is desirable for the complete eradication of tumors. To this end, a dual chemodrug-loaded theranostic system based on single walled carbon nanohorns (SWNHs) is developed for targeting both primary breast tumors and their lung metastases.

Methods: SWNHs were first modified simultaneously with poly (maleic anhydride-alt-1-octadecene) (C₁₈PMH) and methoxypolyethyleneglycol-b-poly-D, L-lactide (mPEG-PLA) via hydrophobic-hydrophobic interactions and π-π stacking. Then cisplatin and doxorubicin (DOX) (2.9:1 molar ratio) were sequentially loaded onto the modified nanohorns in a noninterfering way. After careful examinations of the release profiles of the loaded drugs and the photothermal performance of the dual chemodrug-loaded SWNHs, termed SWNHs/C₁₈PMH/mPEG-PLA-DOX-Pt, the dual drug chemotherapeutic and chemo-photothermal synergetic therapeutic effects on tumor cells were evaluated. Subsequently, the in vivo behavior and tumor accumulation of the drug-loaded SWNHs were studied by photoacoustic imaging (PAI). For chemo-photothermal therapy of tumors, 4T1 tumor bearing mice were intravenously injected with SWNHs/C₁₈PMH/mPEG-PLA-DOX-Pt at a dose of 10 mg/kg b.w. (in SWNHs) and tumors were illuminated by an 808 nm laser (1W/cm² for 5 min) 24 h post-injection.

Results: DOX and cisplatin were loaded onto the modified SWNHs with high efficiency (44 wt% and 66 wt%, respectively) and released in a pH-sensitive, tandem and sustainable manner. The SWNHs/C₁₈PMH/mPEG-PLA-DOX-Pt had a hydrodynamic diameter of 182 ± 3.2 nm, were highly stable in physiological environment, and had both dual drug chemotherapeutic (CI = 0.439) and chemo-photothermal synergistic antitumor effects (CI = 0.396) in vitro. Moreover, the dual drug-loaded SWNHs had a long blood half-life (10.9 h) and could address both the primary breast tumors and their lung metastases after intravenous administration. Consequently, chemo-photothermal combination therapy ablated the primary tumors and simultaneously eradicated the metastatic lung nodules.

Conclusion: Our study demonstrates that SWNHs/C₁₈PMH/mPEG-PLA-DOX-Pt is highly potent for chemo-photothermal combination therapy of primary tumors and cocktail chemotherapy of their metastases at a distant site.

Treatment strategies for endometrial cancer: current practice and perspective

PURPOSE OF REVIEW

Endometrial cancer incidence is increasing in North America and is a major cause of morbidity and mortality in women. We review recent literature published on treatment of endometrial cancer and highlight areas of active interest.

RECENT FINDINGS

There has been movement toward minimal invasive surgery at diagnosis; lymph node staging remains controversial and continues to be investigated. Progress has been made to establish consensus on endometrial cancer risk classification to promote consistency for future trial design. Molecular characterization of endometrial cancer and its integration into clinicopathological profiling to develop predictive biomarkers for treatment selection are active areas of research. Optimal adjuvant treatment strategy in high-risk endometrial cancer remains to be defined with recognition of treatment-related toxicity. Despite encouraging results in drug development for treatment of advanced/recurrent endometrial cancer, no targeted therapies beyond hormonal therapy are approved. There is an urgent need for scientifically validated therapy with predictive biomarkers.

SUMMARY

Our understanding of endometrial cancer has evolved through improvements in molecular biology, allowing improved definition of target-specific therapies. The precise role and sequence of conventional and targeted therapies, including immunotherapy, will require careful attention to the design of clinical trials with translational emphasis to allow the discovery, validation, and implementation of predictive biomarkers into clinical care.

New therapies for advanced, recurrent, and metastatic endometrial cancers

Endometrial cancer is the most common gynecologic malignancy in the United States, accounting for 6% of cancers in women. In 2017, an estimated 61,380 women were diagnosed with endometrial cancer, and approximately 11,000 died from this disease. From 1987 to 2008, there was a 50% increase in the incidence of endometrial cancer, with an approximate 300% increase in the number of associated deaths. Although there are many chemotherapeutic and targeted therapy agents approved for ovarian, fallopian tube and primary peritoneal cancers, since the 1971 approval of megestrol acetate for the palliative treatment of advanced endometrial cancer, only pembrolizumab has been Food and Drug Administration (FDA)-approved for high microsatellite instability (MSI-H) or mismatch repair deficient (dMMR) endometrial cancer; this highlights the need for new therapies to treat advanced, recurrent, metastatic endometrial cancer. In this review, we discuss current and emerging treatment options for endometrial cancer, including chemotherapy, targeted therapy, and immunotherapy. The National Cancer Institute (NCI) and others are now focusing their efforts on the design of scientifically rational targeted therapy and immunotherapy trials for specific molecular phenotypes of endometrial cancer. This is essential for the advancement of cancer care for women, which is threatened by a severe enrollment decline of approximately 80% for gynecologic oncology clinical trials.

Synergistic Cisplatin/Doxorubicin Combination Chemotherapy for Multidrug-Resistant Cancer via Polymeric Nanogels Targeting Delivery

Combination chemotherapy has been proposed to achieve synergistic effect and minimize drug dose for cancer treatment in clinic application. In this article, the stimuli-responsive polymeric nanogels (<100 nm in size) based on poly(acrylic acid) were designed as codelivery system for doxorubicin and cisplatin to overcome drug resistance. By chelation, electrostatic interaction, and π-π stacking interactions, the nanogels could encapsulate doxorubicin and cisplatin with designed ratio and high capacity. Compared with free drugs, the nanogels could deliver more drugs into MCF-7/ADR cells. Significant accumulation in tumor tissues was observed in the biodistribution experiments. The in vitro antitumor studies demonstrated the superior cell-killing activity of the nanogel drug delivery system with a combination index of 0.84, which indicated the great synergistic effect. All the antitumor experimental data revealed that the combination therapy was effective for the multidrug-resistant MCF-7/ADR tumor with reduced side effects.

Stabilized Polymer Micelles for the Development of IT-147, an Epothilone D Drug-Loaded Formulation

Epothilones have demonstrated promising potential for oncology applications but suffer from a narrow therapeutic window. Epothilone D stabilizes microtubules leading to apoptosis, is active against multidrug-resistant cells, and is efficacious in animal tumor models despite lack of stability in rodent plasma. Clinical development was terminated in phase II due to dose limiting toxicities near the efficacious dose. Taken together, this made epothilone D attractive for encapsulation in a stabilized polymer micelle for improved safety and efficacy. We have designed a library of triblock copolymers to develop IT-147, a lead formulation of epothilone D that extends plasma circulation for accumulation in the tumor environment, and potentially decrease systemic exposure to reduce dose limiting toxicities. The drug loading efficiency for IT-147 exceeds 90%, is 75 nm in diameter, and demonstrates pH-dependent release of epothilone D without chemical conjugation or enzymatic activation. Administration of IT-147 at 20 mg/kg increases exposure of epothilone D to the plasma compartment over 6-fold compared to free drug. At the same dose, 20 mg/kg epothilone D from IT-147 is considered the no observed adverse effect level (NOAEL) but is the maximum tolerated dose for free drug. Consequently, IT-147 is positioned to be a safer, more effective means to deliver epothilone D.