Gemcitabine, docetaxel, and bevacizumab in relapsed and refractory pediatric sarcomas

Use of Antiangiogenic Therapies in Pediatric Solid Tumors

Cancer is an important cause of death in childhood. In recent years, scientists have made an important effort to achieve greater precision and more personalized treatments against cancer. But since only a few pediatric patients have identifiable therapeutic targets, other ways to stop the neoplastic cell proliferation and dissemination are needed. Therefore, the inhibition of general processes involved in the growth and behavior of tumors can be a relevant strategy for the development of new cancer therapies. In the case of solid tumors, one of these processes is angiogenesis, essential for tumor growth and generation of metastases. This review summarizes the results obtained with the use of antiangiogenic drugs in the main pediatric malignant solid tumors and also an overview of clinical trials currently underway. It should be noted that due to the rarity and heterogeneity of the different types of pediatric cancer, most studies on antiangiogenic drugs include only a small number of patients or isolated clinical cases, so they are not conclusive and further studies are needed.

Targeting Tumor-Associated Macrophages in the Pediatric Sarcoma Tumor Microenvironment

For many pediatric sarcoma patients, multi-modal therapy including chemotherapy, radiation, and surgery is sufficient to cure their disease. However, event-free and overall survival rates for patients with more advanced disease are grim, necessitating the development of novel therapeutic approaches. Within many pediatric sarcomas, the normal immune response, including recognition and destruction of cancer cells, is lost due to the highly immune suppressive tumor microenvironment (TME). In this setting, tumor cells evade immune detection and capitalize on the immune suppressed microenvironment, leading to unchecked proliferation and metastasis. Recent preclinical and clinical approaches are aimed at understanding this immune suppressive microenvironment and employing cancer immunotherapy in an attempt to overcome this, by renewing the ability of the immune system to recognize and destroy cancer cells. While there are several factors that drive the attenuation of immune responses in the sarcoma TME, one of the most remarkable are tumor associated macrophage (TAMs). TAMs suppress immune cytolytic function, promote tumor growth and metastases, and are generally associated with a poor prognosis in most pediatric sarcoma subtypes. In this review, we summarize the mechanisms underlying TAM-facilitated immune evasion and tumorigenesis and discuss the potential therapeutic application of TAM-focused drugs in the treatment of pediatric sarcomas.

GEIS-21: a multicentric phase II study of intensive chemotherapy including gemcitabine and docetaxel for the treatment of Ewing sarcoma of children and adults: a report from the Spanish sarcoma group (GEIS)

BACKGROUND

First Spanish trial of Ewing sarcoma (ES) including adults and children with the aim to test the efficacy of Gemcitabine and Docetaxel (G/D) in newly diagnosed high-risk (HR) patients.

METHODS

This was a prospective, multicentric, non-randomised, open study for patients ⩽40 years with newly diagnosed ES. HR patients (metastatic, axial-pelvic primaries or bone marrow micrometastasis) received 2 window cycles of G/D. Patients with an objective response (OR) to G/D received 12 monthly cycles of G/D after completion of mP6. The primary end point was the OR rate to the G/D window phase and the event-free survival (EFS) and overall survival (OS) for all patients. The study is registered at ClinicalTrials.gov (identifier: NCT00006734).

RESULTS

Forty-three patients were enroled, median age 17 years (range, 3-40). After a median follow-up of 43.4 months, the 5-year OS rate is 55.0% (95% CI, 41-74%) with an EFS of 50.0% (95% CI, 36-68%). The 5-year OS and EFS rates for standard risk (SR) patients was 76.0% (95% CI, 57-100%) and 71.0% (CI, 54-94%); for HR 36.0% (CI, 20-65%) and 29.0% (CI, 15-56%). Twelve of 17 (70.6%) high-risk (HR) patients showed an OR (7 PR and 5 SD) to G/D window therapy. The 5-year OS rate for patients ⩽18 years of age was 74.0% (CI, 56-97%) and 31.0% for >18 years (95% CI, 15-66%), P<0.001. Grade 4 adverse events during mP6 occurred in 28/39 of patients (72%) and did not correlate with age. Multivariate survival analyses with <18 vs ⩾18 and risk groups significant differences, P<0.00001. Using a Cox model for OS, both age and risk group were statistically significant (P=0.0011 and P=0.0065, respectively).

CONCLUSIONS

Age at diagnosis is an independent prognostic factor superior to the presence of metastases with 18 years as the strongest cut-off. The mP6 regimen provided survival curves that plateau at 3 years and G/D produced significant responses in HR-ES that is worth further exploring.

Docetaxel, bevacizumab, and gemcitabine for very high risk sarcomas in adolescents and young adults: A single-center experience

BACKGROUND

Adolescent and young adult (AYA) patients with very high risk sarcomas have poor outcomes and are in need of novel therapies.

PROCEDURE

From January 2005 to February 2016, we retrospectively identified all AYA patients with relapsed or metastatic high-grade sarcomas, who were treated with at least one cycle of docetaxel (T), bevacizumab (A), and gemcitabine (G) (TAG ; T = 100 mg/m² Day 8, A = 15 mg/kg Day 1, G = 1,000 mg/m² Days 1 and 8).

RESULTS

Fourteen patients, median age of 20 (15-30), received a total of 80 cycles of TAG, and were followed for a median of 83 months. Diagnosis included osteosarcoma (OST; 8), Ewing sarcoma (3), and soft tissue sarcoma (3). Five of 14 patients achieved clinical remission (CR), 3 had partial responses (PR), 3 had stable disease (SD), and 3 had progressive disease (PD). The median progression-free survival and overall survival were 7 and 19 months, respectively. The objective response rate (CR + PR) and tumor control rate (CR + PR + SD) were 57% and 79%, respectively, with two patients alive after 5 years; toxicities included thrombocytopenia, neutropenia, and capillary leak syndrome.

CONCLUSIONS

Our study builds on previous studies utilizing TAG in adult leiomyosarcoma (LMS) by focusing on AYA, non-LMS sarcomas, especially OST. Our experience suggests that TAG is well tolerated and has activity in very high risk sarcomas in AYA.

Pazopanib in the management of advanced soft tissue sarcomas

Therapy of soft tissue sarcomas represents an area of significant unmet need in oncology. Angiogenesis has been explored as a potential target both preclinically and clinically, with suggestions of activity. Pazopanib is a multitargeted tyrosine kinase inhibitor with prominent antiangiogenic effects. In a Phase II study, pazopanib demonstrated activity in strata enrolling patients with leiomyosarcomas, synovial sarcomas, or other sarcomas but not those enrolling adipocytic sarcomas. PALETTE, the pivotal Phase III trial, demonstrated improved progression-free survival versus placebo in pazopanib-treated patients previously treated for advanced soft tissue sarcomas. No survival benefit was observed, and adipocytic sarcomas were excluded. Health-related quality-of-life assessments indicated significant decrements in several areas affected by pazopanib toxicities, but no global deterioration. Cost-effectiveness analyses indicate that pazopanib therapy may or may not be cost-effective in different geographic settings. Pazopanib provides important proof-of-concept for antiangiogenic therapy in soft tissue sarcomas. Its use can be improved by further biological studies of its activity profile in sarcomas, studies of biological rational combinations, and clinicopathologic/biological correlative studies of activity to allow better drug targeting.

Targeted antiangiogenic agents in combination with cytotoxic chemotherapy in preclinical and clinical studies in sarcoma

Sarcomas are a heterogeneous group of mesenchymal malignancies. In recent years, studies have demonstrated that inhibition of angiogenic pathways or disruption of established vasculature can attenuate the growth of sarcomas. However, when used as monotherapy in the clinical setting, these targeted antiangiogenic agents have only provided modest survival benefits in some sarcoma subtypes, and have not been efficacious in others. Preclinical and early clinical data suggest that the addition of conventional chemotherapy to antiangiogenic agents may lead to more effective therapies for patients with these tumors. In the current review, the authors summarize the available evidence and possible mechanisms supporting this approach.

A Pilot Study of Circulating Endothelial and Hematopoietic Progenitor Cells in Children With Sarcomas

Utilizing a multiparametric flow cytometry protocol, we assessed various cell types implicated in tumor angiogenesis that were found circulating in the peripheral blood of children with sarcomas (cases) based on their cell surface antigen expression. Circulating endothelial cells (CECs), endothelial colony-forming cells (ECFCs), and the ratio of 2 distinct populations of circulating hematopoietic stem and progenitor cells (CHSPCs), the proangiogenic CHSPCs (pCHSPCs) and nonangiogenic CHSPCs (nCHSPCs) were enumerated. Multiparametric flow cytometry was analyzed in cases at baseline and at 4 additional timepoints until the end of treatment and levels compared with each other and with healthy controls. At all timepoints, cases had significantly lower levels of CECs, but elevated ECFCs and a pCHSPC:nCHSPC ratio compared with controls (all P-values <0.05). There was no significant difference in any of the cell types analyzed based on tumor histology, stage (localized vs. metastatic), or tumor size. After treatment, only the CECs among the complete responders were significantly lower at end of therapy (P<0.01) compared with nonresponders, whereas the ECFCs among all cases significantly increased (P<0.05) compared with baseline. No decline in the pCHSPC:nCHSPC ratio was observed despite tumor response. On the basis of these results, a validation of CECs as prognostic biomarker is now warranted.

Gemcitabine and docetaxel for the treatment of children and adolescents with recurrent or refractory osteosarcoma: Korea Cancer Center Hospital experience

BACKGROUND

We evaluated the efficacy of gemcitabine and docetaxel chemotherapy (GEM + DOC) in children and adolescents with recurrent or refractory osteosarcoma.

METHODS

Data of 28 patients (20 male, 8 female) who received gemcitabine (675 or 900 mg/m(2) on days 1 and 8) and docetaxel (100 mg/m(2) on day 8) at Korea Cancer Center Hospital were retrospectively reviewed.

RESULTS

Patients (ages 5.0-19.7 years) received a total of 96 courses of chemotherapy (median 3 courses; range, 1-8 courses) and were followed for a median of 14.9 months (range, 0.6-81.4 months). Eleven patients received GEM + DOC after surgery as adjuvant chemotherapy. Seventeen patients received GEM + DOC as palliative therapy, and were eligible for response evaluation; there were three (17.6%) complete response (CR, including two metabolic CR), one (5.9%) partial responses (PR), and three (29.4%) stable disease (SD). The objective response rate (CR + PR) and tumor control rate (CR + PR + SD) were 23.5% and 41.2%, respectively. The median duration of response was 11.2 months (range, 2.8-14.6 months). Dose of gemcitabine (675 or 900 mg/m(2)) did not influence the response rate. Overall survival at 1-year was 53.6 ± 9.4% and patients who received GEM + DOC as adjuvant chemotherapy fared better than those who received GEM + DOC as palliative therapy (72.7 ± 13.4% vs. 35.3 ± 11.6%, P = 0.006).

CONCLUSION

GEM + DOC showed some activity in osteosarcoma. Better than expected survival after GEM + DOC was seen both in patients with and without surgery. These results may indicate that dose dense combinations of gemcitabine and taxanes (e.g., gemcitabine + nab-paclitaxel) should be investigated in bone sarcomas.

Pilot study of vincristine, oral irinotecan, and temozolomide (VOIT regimen) combined with bevacizumab in pediatric patients with recurrent solid tumors or brain tumors

BACKGROUND

The combination of vincristine, oral irinotecan, and temozolomide (VOIT regimen) has shown antitumor activity in a pediatric Phase I trial. To further potentiate synergy, we assessed the safety and feasibility of adding bevacizumab to VOIT for children and young adults with recurrent tumors.

METHODS

Patients received vincristine (1.5 mg/m(2) on day 1), oral irinotecan (90 mg/m(2) on days 1-5), temozolomide (100-150 mg/m(2) on days 1-5), and bevacizumab (15 mg/kg on day 1) in 3-week cycles, which were repeated for up to six cycles. Cefixime prophylaxis was used to reduce irinotecan-associated diarrhea.

RESULTS

Thirteen patients received 36 total cycles. Six of the first 10 patients required dose reductions due to toxicity during the first cycle (n = 3) or subsequent cycles (n = 3), and these grade 3 side effects included prolonged nausea, dehydration, anorexia, neuropathy, diarrhea, and abdominal pain, as well as prolonged grade 4 neutropenia. After reducing daily temozolomide to 100 mg/m(2) , three additional patients tolerated therapy well without the need for dose reductions. Toxicities attributed to bevacizumab were limited to grade 1 epistaxis (1) and grade 2 proteinuria (1). Tumor responses were seen in both patients with Ewing sarcoma.

CONCLUSIONS

Reducing temozolomide from 150 to 100 mg/m(2) /day improved tolerability, and treatment with this lower temozolomide dose was feasible and convenient as outpatient therapy. Although responses were seen in Ewing sarcoma, the benefit of adding bevacizumab remains unclear.