Phase II study of weekly docetaxel and fixed dose rate gemcitabine in patients with previously treated advanced soft tissue and bone sarcoma

A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

BACKGROUND/OBJECTIVE

To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.

METHODS

A systematic review of trials registered on trial registries between 01/01/2017-14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.

RESULTS

Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.

CONCLUSION

Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies.

Chemotherapeutic drugs for soft tissue sarcomas: a review

Despite the low incidence of soft tissue sarcomas (STSs), hundreds of thousands of new STS cases are diagnosed annually worldwide, and approximately half of them eventually progress to advanced stages. Currently, chemotherapy is the first-line treatment for advanced STSs. There are difficulties in selecting appropriate drugs for multiline chemotherapy, or for combination treatment of different STS histological subtypes. In this study, we first comprehensively reviewed the efficacy of various chemotherapeutic drugs in the treatment of STSs, and then described the current status of sensitive drugs for different STS subtypes. anthracyclines are the most important systemic treatment for advanced STSs. Ifosfamide, trabectedin, gemcitabine, taxanes, dacarbazine, and eribulin exhibit certain activities in STSs. Vinca alkaloid agents (vindesine, vinblastine, vinorelbine, vincristine) have important therapeutic effects in specific STS subtypes, such as rhabdomyosarcoma and Ewing sarcoma family tumors, whereas their activity in other subtypes is weak. Other chemotherapeutic drugs (methotrexate, cisplatin, etoposide, pemetrexed) have weak efficacy in STSs and are rarely used. It is necessary to select specific second- or above-line chemotherapeutic drugs depending on the histological subtype. This review aims to provide a reference for the selection of chemotherapeutic drugs for multi-line therapy for patients with advanced STSs who have an increasingly long survival.

Systematic review of phase-I/II trials enrolling refractory and recurrent Ewing sarcoma: Actual knowledge and future directions to optimize the research

BACKGROUND

Optimal Phase-II design to evaluate new therapies in refractory/relapsed Ewing sarcomas (ES) remains imperfectly defined.

OBJECTIVES

Recurrent/refractory ES phase-I/II trials analysis to improve trials design.

METHODS

Comprehensive review of therapeutic trials registered on five databases (who.int/trialsearch, clinicaltrials.gov, clinicaltrialsregister.eu, e-cancer.fr, and umin.ac.jp) and/or published in PubMed/ASCO/ESMO websites, between 2005 and 2018, using the criterion: (Ewing sarcoma OR bone sarcoma OR sarcoma) AND (Phase-I or Phase-II).

RESULTS

The 146 trials identified (77 phase-I/II, 67 phase-II, and 2 phase-II/III) tested targeted (34%), chemo- (23%), immune therapies (19%), or combined therapies (24%). Twenty-three trials were ES specific and 48 had a specific ES stratum. Usually multicentric (88%), few trials were international (30%). Inclusion criteria cover the recurrent ES age range for only 12% of trials and allowed only accrual of measurable diseases (RECIST criteria). Single-arm design was the most frequent (88%) testing mainly single drugs (61%), only 5% were randomized. Primary efficacy outcome was response rate (RR=CR+PR; Complete+Partial response) (n = 116/146; 79%), rarely progression-free or overall survival (16% PFS and 3% OS). H0 and H1 hypotheses were variable (3%-25% and 20%-50%, respectively). The 62 published trials enrolled 827 ES patients. RR was poor (10%; 15 CR=1.7%, 68 PR=8.3%). Stable disease was the best response for 186 patients (25%). Median PFS/OS was of 1.9 (range 1.3-14.7) and 7.6 months (5-30), respectively. Eleven (18%) published trials were considered positive, with median RR/PFS/OS of 15% (7%-30%), 4.5 (1.3-10), and 16.6 months (6.9-30), respectively.

CONCLUSION

This review supports the need to develop the international randomized phase-II trials across all age ranges with PFS as primary endpoint.

A multicentric randomized phase II clinical trial evaluating high-dose thiotepa as adjuvant treatment to standard chemotherapy in patients with resectable relapsed osteosarcoma

BACKGROUND

The role of high-dose chemotherapy in relapsing osteosarcomas has not been established. We evaluated the efficacy and tolerance of high-dose thiotepa (HDTp) after standard chemotherapy (SCT) in patients with relapsed osteosarcoma.

PATIENTS AND METHODS

This randomised open-label phase II study enrolled patients 1-50 years, with local or metastatic relapse of a high-grade osteosarcoma, not progressive after two cycles of SCT, for whom a complete surgery can be achievable following treatment. The trial assigned enrolled patients in a 1:1 ratio to receive two additional courses of SCT + HDTp and autologous transplantation (Arm A), or SCT alone (Arm B). Surgery for complete resection was scheduled as soon as feasible. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS) and safety.

RESULTS

From September 2009 to November 2016, 44 patients were randomised (A:22; B:22). In total, 54.5% were males, and the median age was 16 years (9-32years). The two-year OS rate was 66.7% (95% CI 42.5-82.5) (SCT + HDTp, Arm A) versus 50.0% (95% CI 28.2-68.4) for SCT alone (Arm B). Median OS was 27.4 and 24.8 months, respectively (hazard ratio [HR] 0.826, 95% CI 0.393-1.734; p = 0.6123). Median PFS was 15.6 (8.9-24.9) months in Arm A versus 7.2 (4.8-33.3) months in Arm B, p = 0.3845. Among the 22 patients treated with SCT + HDTp, 16 (72.7%) experienced at least one grade ≥3 adverse events versus 18/22 (81.8%) patients treated with SCT. No toxic death occurred.

CONCLUSION

Adjuvant HDTp failed to significantly improve OS and PFS in resectable relapsed osteosarcomas. Despite a trend of prolonged survival and an acceptable toxicity, thiotepa cannot be recommended.

KEY MESSAGE

HDTp and autologous transplantation added to SCT did not improve OS and PFS in patients with resectable relapsed osteosarcomas. Despite a trend of prolonged survival, thiotepa cannot be recommended.

Arginine Starvation and Docetaxel Induce c-Myc-Driven hENT1 Surface Expression to Overcome Gemcitabine Resistance in ASS1-Negative Tumors

PURPOSE

The response to acute and long-term arginine starvation results in a conditional adaptive metabolic reprogramming that can be harnessed for therapeutic opportunities in ASS1-negative tumors. Here, we investigate the underlying biology of priming ASS1- tumors with arginine deiminase (ADI-PEG20) before treatment with gemcitabine (GEM) and docetaxel (DTX) in sarcoma, pancreatic cancer, and melanoma cell lines.

EXPERIMENTAL DESIGN

ASS1- tumor cell lines were treated to create LTAT (long-term ADI treated) cell lines (ASS1+) and used for drug combination studies. Protein expression of ASS1, dCK, RRM2, E2F1, c-MYC, and hENT1 was measured. c-MYC activity was determined, live-cell immunofluorescent studies for hENT1, uptake assays of FITC-cytosine probe, and rescue studies with a c-MYC inhibitor were all determined in the presence or absence of the ADI-PEG20:GEM:DTX.

RESULTS

In examining modulations within the pyrimidine pathway, we identified that the addition of DTX to cells treated with ADI-PEG20 resulted in translocation of stabilized c-Myc to the nucleus. This resulted in an increase of hENT1 cell-surface expression and rendered the cells susceptible to GEM. In vivo studies demonstrate that the combination of ADI-PEG20:GEM:DTX was optimal for tumor growth inhibition, providing the preclinical mechanism and justification for the ongoing clinical trial of ADI-PEG20, GEM, and DTX in sarcoma.

CONCLUSIONS

The priming of tumors with ADI-PEG20 and DTX results in the stabilization of c-MYC potentiating the effect of GEM treatment via an increase in hENT1 expression. This finding is applicable to ASS1-deficient cancers that are currently treated with GEM.

Gemcitabine and docetaxel combination chemotherapy for advanced bone and soft tissue sarcomas: protocol for an open-label, non-randomised, Phase 2 study

Background

The prognosis of patients with metastatic or advanced sarcomas is poor and there are few options for treatment. Several studies have shown that gemcitabine and docetaxel (GD) combination chemotherapy has antitumor activity against various subtypes of sarcoma. Recently, some studies have shown a favourable outcome for GD combination chemotherapy for relapsed high-grade osteosarcoma and spindle cell sarcoma of bone. If the effectiveness of GD is proven, this will result in new treatment options for advanced bone and soft tissue sarcomas (STS). The aim of this prospective Phase 2 study is to evaluate the efficacy and toxicity of the GD combination in patients with advanced bone sarcomas and STS.

Methods

This is a Phase 2, single-arm, open-label study to investigate the efficacy and safety of combination chemotherapy with GD for advanced bone sarcomas and STS and will enrol 20 patients. The patients will receive gemcitabine 900 mg/m² on Days 1 and 8, and docetaxel 70 mg/m² on Day 8 in 3-week cycles until disease progression or other evidence of treatment failure. The primary aim of this study is to analyse GD’s effect on progression-free survival (PFS). The secondary objectives are to analyse treatment efficacy and safety in terms of response rate, tumour control rate, overall survival, and adverse event rate. The length of follow-up will be 5 years.

Discussion

This study will evaluate the efficacy and safety of combination therapy with gemcitabine and docetaxel for bone sarcomas and STS. If this combination proves to be acceptable, it could be used for as second, third, or later line therapy for patients with sarcomas (especially bone sarcomas). In the future, the role of various treatments, including GD therapy, will be clarified for specific subtypes of sarcoma.

Trial registration

This study was registered as UMIN000031004 (University Hospital Medical Information Network-Clinical Trial Registry: UMIN-CTR) on 1 March 1 2018 and with the Japan Registry of Clinical Trials (jRCT) as jRCTs051180042 on 30 January 2019. The posted information will be updated as needed to reflect protocol amendments and study progress.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5923-7) contains supplementary material, which is available to authorized users.

Overall survival and histology-specific subgroup analyses from a phase 3, randomized controlled study of trabectedin or dacarbazine in patients with advanced liposarcoma or leiomyosarcoma

BACKGROUND

We performed a randomized phase 3 study of trabectedin versus dacarbazine in previously-treated patients with liposarcoma/leiomyosarcoma (LPS/LMS).

METHODS

Patients were randomized 2:1 to trabectedin (n = 384) or dacarbazine (n = 193) administered intravenously every 3 weeks. The primary objective was overall survival (OS). Secondary objectives were progression-free survival, objective response rate, safety, and patient-reported outcomes, all previously reported and demonstrating superior disease control with trabectedin. Results of the final OS analysis in preplanned subgroups of patients with LPS/LMS are presented.

RESULTS

At the time of the final OS analysis, 577 patients had been assigned randomly, including 423 (73%) with LMS and 154 (27%) with LPS. The median duration of treatment exposure was higher in the trabectedin arm compared with the dacarbazine arm (4 vs 2 cycles), as was the proportion of patients receiving an extended number of therapy courses (≥6 cycles: 42% vs 22%). This pattern was consistent across histological subgroups: the median number of treatment cycles (4 vs 2 for both subgroups) and proportion of patients with ≥6 treatment cycles (LMS, 43% vs 24%; LPS, 40% vs 16%). Despite improved disease control by trabectedin, no improvement in OS was observed; the final median OS for trabectedin versus dacarbazine was 13.7 versus 13.1 months (P = .49). Sensitivity analyses of OS suggest confounding by post-study anticancer therapies, which were utilized in most patients in both treatment arms (71% vs 69%, respectively).

CONCLUSION

The final OS results demonstrated comparable survival between LPS/LMS patients receiving trabectedin or dacarbazine, which is consistent with the interim analysis results. Both LPS and LMS demonstrated improved disease control with trabectedin.

Treatment of advanced, metastatic soft tissue sarcoma: latest evidence and clinical considerations

Soft tissue sarcoma (STS) is a biologically heterogeneous malignancy with over 50 subtypes. Historically, there have been few systemic treatment options for this relatively rare disease. Traditional cytotoxic agents, such as anthracyclines, alkylating agents, and taxanes have limited clinical benefit beyond the first-line setting; across all high-grade STS subtypes, median overall survival remains approximately 12-18 months for advanced metastatic disease. The development of targeted therapies has led to recent US Food and Drug Administration approval of four new treatments for high-grade STS in the advanced metastatic setting. Among these, olaratumab is most notable for its improvement in overall survival for patients with anthracycline-naïve disease. Further progress in STS management will rely on novel trial design, subtype-specific therapies and validation of biomarkers to tailor therapy. Immunotherapy has shown promise as a new, but yet undiscovered frontier in the management of STS.

Gemcitabine and Docetaxel Combination for Advanced Soft Tissue Sarcoma: A Nationwide Retrospective Study

PURPOSE

This nationwide retrospective study was conducted to evaluate the efficacy and safety of combined gemcitabine and docetaxel (GD) as an off-label therapy for advanced soft tissue sarcoma, which has limited treatment options owing to its rare occurrence.

MATERIALS AND METHODS

A total of 228 patients received GD therapy for advanced soft tissue sarcoma from 2009 to 2014 in Korea. We retrospectively reviewed the clinical medical records and claims data of these patients.

RESULTS

A total of 218 patients in 20 medical centers were included in the final analysis (median age, 50.0 years). The objective response rate was 15.1% (34/218, in the leiomyosarcoma subgroup; 26.3%). The median overall survival and progression-free survival were 10.3 months (95% confidence interval [CI], 8.4 to 12.2) and 3.3 months (95% CI, 2.8 to 4.7), respectively. The treatment was discontinued in 7.8% of patients owing to adverse events; however, there was no adverse event-related death. Neutropenia (35.7%) and anemia (15.1%) were the most frequent grade 3/4 toxicities. Univariate analysis for identifying the predictors of the progression-free survival period revealed that patients aged ≤ 50 years had a hazard ratio of 1.388 (95% CI, 1.027 to 1.875; p < 0.05) relative to those aged > 50 years, and the group with leiomyosarcoma had a hazard ratio of 0.693 (95% CI, 0.493 to 0.975; p < 0.05) relative to the group with other histopathological subtypes.

CONCLUSION

GD therapy was tolerable and effective for Korean patients with soft tissue sarcoma. In conclusion, for patients with advanced soft tissue sarcoma, especially leiomyosarcoma, GD therapy could be an important therapeutic option.

Feasibility and efficacy of gemcitabine and docetaxel combination chemotherapy for bone and soft tissue sarcomas: multi-institutional retrospective analysis of 134 patients

Background

Bone and soft tissue sarcomas (BSTS) are rare malignant tumors. Recently, the combination of gemcitabine and docetaxel (GD) was shown to have activity as second-line setting in BSTS. However, the efficacy as first-line and adjuvant settings and precise profiles of adverse events in Japanese patients are not known yet. In the present study, the feasibility and efficacy of GD in patients with BSTS were investigated.

Methods

Patients with BSTS treated with GD in our institutions were retrospectively analyzed. Information regarding clinical features, adverse events, and outcome was collected and statistically studied. Factors related to survival were analyzed using log-rank test and Cox proportional hazard regression method.

Results

A total of 134 patients were analyzed. GD was carried out as adjuvant setting in 9, first-line in 23, second-line in 56, and third-or-greater line in 46 patients. The response rate (RR) for all patients was 9.7%. RR for the patients treated as adjuvant or first-line setting was 18.8%, whereas that as second-or-greater line was 6.9%. The median progression-free survival (PFS) and overall survival (OS) of all patients were 4.8 (95% CI 3.5–6.1) and 16.4 (95% CI 9.8–22.9) months, respectively. Survival tended to be better in the patients treated as first-line than in those treated as second-or-greater line. Multivariate analysis demonstrated that history of prior chemotherapy (p = 0.046) and response to GD (p = 0.009) was significantly associated with PFS and OS, respectively. The leucopenia and neutropenia were the most frequent adverse events, and grade 3 or 4 leucopenia and neutropenia were observed in 69.4 and 72.4% of the patients. Grade 2 or 3 pneumonitis was observed in one (0.7%) and four (3.0%) patients, respectively. All the patients with pneumonitis had experienced prior chemotherapy and/or radiotherapy.

Conclusions

GD used as both first- and second/later line is effective chemotherapy for a proportion of patients with advanced BSTS. Higher response rate and better outcome was achieved in chemotherapy-naïve patients. This regimen is associated with high incidence of severe hematological toxicity, as well as the risk of severe pneumonitis, especially in pre-treated patients. GD is promising for further analysis by phase III study for the patients with BSTS.

Initial testing (stage 1) of the anti-microtubule agents cabazitaxel and docetaxel, by the pediatric preclinical testing program

BACKGROUND

Although microtubule-destabilizing agents (principally vincristine) are in common use in pediatric oncology, the microtubule-stabilizing taxanes are uncommonly used to treat childhood cancers. Cabazitaxel has been reported to have activity superior to that of docetaxel in preclinical models of multidrug-resistant adult cancers, and it was active in patients who had progressed on or after docetaxel. The PPTP conducted a comparison of these two agents against the PPTP in vitro panel and against a limited panel of solid tumor xenografts.

PROCEDURES

Cabazitaxel and docetaxel were tested against the PPTP in vitro cell line panel at concentrations from 0.01 to 0.1 μM and in vivo against a subset of the PPTP solid tumor xenograft models at a dose of 10 or 7.5 mg/kg on an every 4 days × 3 I.V. schedule.

RESULTS

In vitro, both cabazitaxel and docetaxel had similar potency (median rIC50 0.47 nM and 0.88 nM, respectively) and a similar activity profile, with Ewing sarcoma cells being significantly more sensitive to both agents. In vitro sensitivity to docetaxel inversely correlated with mRNA expression for ABCB1, but the correlation with ABCB1 expression was weaker for cabazitaxel. In vivo cabazitaxel demonstrated significantly greater activity than docetaxel in five of 12 tumor models, inducing regressions in six models compared with three models for docetaxel.

CONCLUSIONS

Cabazitaxel demonstrated superior activity compared to docetaxel. The lower cabazitaxel systemic exposure tolerated in humans compared to mice needs to be considered when extrapolating these results to the clinical setting.

A Phase II Study of Gemcitabine, Vincristine, and Cisplatin As Second-Line Treatment for Patients with Advanced Soft Tissue Sarcoma

Patients with advanced soft tissue sarcoma (aSTS) typically have a poor prognosis. Patients progressing to doxorubicin-based regimen have limited therapeutic options. Monotherapy with cytotoxic drugs appears to have only modest activity in the second-line setting. The purpose of this phase II study was to prospectively evaluate the safety and efficacy of combination regimen with gemcitabine, vincristine, and cisplatin (GVP) as a salvage treatment for patients with aSTS.Eligible patients were female with 18∼75 years old, and had aSTS that had progressed after 1 prior anthracyclines-based chemotherapy regimen. Patients were treated with 1,000 mg/m gemcitabine intravenously (IV) on days 1 and 8, 1.4 mg/m (max 2 mg) vincristine IV on day 1 and 25 mg/m cisplatin IV on days 1 through 3 every 21 days until disease progression, unacceptable toxicity or up to 6 cycles. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), over response rate (ORR) and safety. This trial was registered with http://www.clinicaltrials.gov (no. NCT01192633).A total of 26 patients with a median age 47 years (21-72) were recruited. ORR was 23.1% [1 complete response and 5 partial responses]. The median PFS and OS were 4.8 (95% CI, 0.1-9.5) months and 15.0 (95% CI, 6.1-23.9) months, respectively. Grade 3/4 hematologic toxicities included neutropenia (34.6%), leukopenia (23.1%), thrombocytopenia (11.5%) and anemia (3.8%). No febrile neutropenia and grade 3/4 non-hematologic toxicities occurred. The most frequent non-hematologic toxicities were nausea/vomiting (50.0%), fatigue (30.8%), and fever (11.5%).We conclude that GVP regimen is effective with a favorable safety profile as the second-line chemotherapy in aSTS patients, which warrants further investigation in a phase III study.

A randomised, open-label, phase II study of neo/adjuvant doxorubicin and ifosfamide versus gemcitabine and docetaxel in patients with localised, high-risk, soft tissue sarcoma

BACKGROUND

Doxorubicin and ifosfamide (AI) is standard therapy for high-risk soft tissue sarcoma (STS) but often causes severe toxicities resulting in hospitalisation. Gemcitabine and docetaxel (GD) has efficacy in metastatic STS and may be better tolerated. We conducted a study to compare toxicities and efficacies of these regimens.

METHODS

This open-label, phase II, single institution trial randomised 80 patients with localised, resectable, high grade STS ⩾ 5 cm to either neo/adjuvant AI or GD. AI was doxorubicin (75 mg/m(2)) and ifosfamide (2.5 g/m(2)/d) on days 1-3 with mesna 500 mg/m(2)/dose. GD was gemcitabine 900 mg/m(2) on days 1, 8 and docetaxel 100mg/m(2) day 8. Both arms included filgrastim. The primary end-point was hospitalisation rate. Secondary end-points included disease-free survival (DFS) and overall survival (OS).

RESULTS

Between November 2004 and August 2012, 80 evaluable patients were randomised, 37 to AI and 43 to GT. In the AI arm, 13/37 (35%) patients were hospitalised versus 11/43 (26%) in the GD arm (p=0.25). Hospitalisation rates were not significantly different after adjusting for age, gender, location, chemotherapy and number of cycles (p=0.17). The 2-year and median DFS in the AI arm were 57% and 37 months, respectively, and 74% and not yet reached, respectively, in the GD arm. The most common serious adverse events with AI were haematologic. Metabolic derangements and constitutional symptoms were most common with GD.

CONCLUSIONS

Hospitalisation rate was less with GD but not statistically significant. There was a trend towards longer DFS with GD, and the regimen was tolerable, suggesting GD merits further study.

Response of conventional chondrosarcoma to gemcitabine alone: a case report

Conventional skeletal chondrosarcoma is a bone neoplasm, which is poorly sensitive to anthracyclines-based chemotherapy. We report on an 18-month-long tumour response to gemcitabine as single agent in a young patient with an advanced secondary peripheral conventional chondrosarcoma, previously treated unsuccessfully with anthracyclines, ifosfamide, platinum, etoposide.

The role of chemotherapy for metastatic, relapsed and refractory osteosarcoma

Despite a large number of publications on outcomes of second-line chemotherapy for osteosarcoma, there is little consensus on efficacy of the therapy.

OBJECTIVE

Our objective was to systematically categorize published evidence for chemotherapy for metastatic, relapsed and refractory osteosarcoma in order to provide an updated and comprehensive analysis of the clinical outcomes.

METHODS

We performed a search of PubMed and EMBASE to identify published articles reporting on validated clinical outcomes measures (the rate of complete response [CR] and partial response [PR], the rate of stable disease [SD] and progressive disease [PD] and the 5-year overall survival) after chemotherapy in patients with metastatic, relapsed and refractory osteosarcoma. A total of 20 articles were identified and stratified by different regimens. Finally, six regimens that have at least two drugs were reviewed. Weighted averages of each outcome were computed.

RESULTS

The weighted average overall response rate (CR + PR) for the combination of ifosfamide, etoposide and high-dose methotrexate therapy was 62 %, and the tumor control rate (CR + PR + SD) was 92.3 %; the highest of all six regimens. The weighted average overall response rate and tumor control rate of ifosfamide-etoposide therapy (41.7 and 77.9 %, respectively) were the highest of the two-drug regimens. Weighted average overall response rate and tumor control rate for the remaining regimens were 20.5 and 56.8 %, respectively, for cyclophosphamide-etoposide; 30.0 and 73.5 % for ifosfamide, carboplatin, and etoposide; 12.0 and 40.0 % for cyclophosphamide-topotecan; and 14.5 and 36.4 % for gemcitabine-docetaxel.

CONCLUSION

A chemotherapy regimen comprising both a cell cycle-specific drug and a cell cycle-nonspecific drug could increase response rates. The combination of ifosfamide and etoposide therapy is our first choice in two-drug regimens. Regarding three-drug regimens, adding a cell cycle-specific drug to ifosfamide-etoposide therapy may result in a better response rate than adding a cell cycle-nonspecific drug, or any other two-drug regimens in current studies. Hence, we recommend the use of second-line chemotherapy based on the combination ifosfamide-etoposide regimen in patients with metastatic, relapsed and refractory osteosarcoma.

Systematic therapy for unresectable or metastatic soft-tissue sarcomas: past, present, and future

Unresectable or metastatic disease occurs in 40% to 60% of soft-tissue sarcoma (STS) patients and portends a poor prognosis. For decades, doxorubicin has formed the backbone of systemic treatment, with response rates of approximately 26%. Patients progressing following first-line therapy were left with few proven options. No other cytotoxic chemotherapy agent or combination has demonstrated superiority to doxorubicin. Advances in targeted therapy of STS have been hindered by STS heterogeneity and poorly understood disease biology. Despite challenges, progress has been made in specific STS subtypes. Here, we highlight the challenges, progress, and lessons learned from STS trials published in the last 20 to 25 years.