Single-Center Experience with Ifosfamide Monotherapy as Second-Line Treatment of Recurrent/Metastatic Osteosarcoma

Anlotinib combined with radiotherapy and chemotherapy for recurrent pelvic osteosarcoma treatment: a case report and literature review

At present, the treatment of recurrent pelvic osteosarcoma is too simple, and most of the patients are treated with chemotherapy, radiotherapy, and/or combined surgery. Here, we report a 29-year-old man diagnosed with local recurrent pelvic osteosarcoma. Imaging showed that the tumor had obvious enhancement and abundant blood vessels. There was no indication of surgery. After the patient's consent was obtained, we used anlotinib as a sequential treatment to chemotherapy. During the first course of adjuvant chemotherapy, we treated the patient with intensity-modulated radiotherapy (IMRT) with a total dose of 60 Gy equivalents. No disease recurrence was reported at 25 months after multimodal combination therapy.

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.

TXNIP inhibits the progression of osteosarcoma through DDIT4-mediated mTORC1 suppression

Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents and children. The pathogenesis of this disease is complex and the mechanisms involved have not been fully elucidated. Thioredoxin-interacting protein (TXNIP), as a member of the α-rhodopsin inhibitory protein family, can combine with thioredoxin to inhibit its antioxidant function. This process inhibits glucose absorption and metabolic rearrangement necessary for the regulation of cellular growth. In recent years, TXNIP has emerged as a new candidate target for tumors. However, the biological function and role of TXNIP in OS remains unclear. This study confirmed the low expression of TXNIP in OS tissues and cells, which was significantly related to the poor survival rate and clinical characteristics of patients with OS. Various cell phenotype experiments have shown that TXNIP inhibits the proliferation, migration, and invasion of OS cells, and promotes their apoptosis. Further studies found that the tumor suppressor effect of TXNIP was mediated by upregulating DNA damage-inducible transcript 4 (DDIT4) and inhibiting the phosphorylation of mechanistic target of rapamycin complex 1 (mTORC1) downstream substrate S6. Based on the above, our study explored the key role of TXNIP/DDIT4/mTORC1 suppression as a regulatory axis in the progression of OS, and laid the foundation for precise targeted therapy for OS.

2-Amino-Pyrrole-Carboxylate Attenuates Homology-Mediated DNA Repair and Sensitizes Cancer Cells to Doxorubicin

Despite a high efficacy of chemotherapy in cancer treatment, acquired resistance of tumors to certain chemotherapeutic agents and frequent side effects remain the major factors of unfavorable prognosis in most cancer patients with unresectable, metastatic and recurrent forms of the disease. The discovery of novel molecular targets in tumors and development of new therapeutic approaches to enhance the efficiency of chemotherapeutic agents remain the biggest challenges in current oncology. Here we examined the ability of pyrrole-based heterocyclic compound 2-APC to sensitize tumor cells to the topoisomerase II inhibitor doxorubicin. The study was performed on human cancer cell lines treated with 2-APC, paclitaxel, and doxorubicin. Expression of DNA repair was investigated by Western blotting, whereas protein-protein interactions were examined by co-immunoprecipitation. The synergism between the chemotherapeutic agents was assessed with the Synergy Finder program. Doxorubicin exhibited moderate cytotoxic effect against cancer cell lines (in particular, osteosarcoma cell lines). 2-APC in non-toxic concentrations substantially potentiated the cytotoxic effect of doxorubicin and induced apoptosis of cancer cells. This activity of 2-APC was due to its ability to impair DNA damage repair by decreasing the content of Rad51 recombinase via promoting its proteasomal degradation. Similar effects were observed for paclitaxel, which affects tubulin polymerization. Therefore, chemotherapeutic agents and chemical compounds interfering with the microtubule dynamics can potentiate the cytotoxic effects of DNA-damaging chemotherapeutic agents via impairment of DNA damage repair mechanisms in cancer cells.

Unveiling Metabolic Vulnerability and Plasticity of Human Osteosarcoma Stem and Differentiated Cells to Improve Cancer Therapy

Defining the metabolic phenotypes of cancer-initiating cells or cancer stem cells and of their differentiated counterparts might provide fundamental knowledge for improving or developing more effective therapies. In this context we extensively characterized the metabolic profiles of two osteosarcoma-derived cell lines, the 3AB-OS cancer stem cells and the parental MG-63 cells. To this aim Seahorse methodology-based metabolic flux analysis under a variety of conditions complemented with real time monitoring of cell growth by impedentiometric technique and confocal imaging were carried out. The results attained by selective substrate deprivation or metabolic pathway inhibition clearly show reliance of 3AB-OS on glycolysis and of MG-63 on glutamine oxidation. Treatment of the osteosarcoma cell lines with cisplatin resulted in additive inhibitory effects in MG-63 cells depleted of glutamine whereas it antagonized under selective withdrawal of glucose in 3AB-OS cells thereby manifesting a paradoxical pro-survival, cell-cycle arrest in S phase and antioxidant outcome. All together the results of this study highlight that the efficacy of specific metabolite starvation combined with chemotherapeutic drugs depends on the cancer compartment and suggest cautions in using it as a generalizable curative strategy.

Efficacy and safety of anlotinib in patients with unresectable or metastatic bone sarcoma: A retrospective multiple institution study

Background

Tyrosine kinase inhibitors (TKIs) such as cabozantinib, regorafenib have demonstrated encouraging activity in prolonging progression‐free survival (PFS) in several bone sarcoma entities in prospective clinical trials. This retrospective study aims to analyze the safety and efficacy of anlotinib, a novel multi‐target TKI, in patients with locally unresectable or metastatic bone sarcoma at three institutions.

Methods

Patients with advanced bone sarcoma administered anlotinib 12 mg once daily, 2 weeks on/1 week off, from June 2018 to June 2020, until disease progression or intolerance of treatment. The primary endpoints were objective response rate (ORR) and PFS.

Results

Forty‐eight patients were analyzed: 27 have osteosarcoma, 9 have chondrosarcoma, 8 have Ewing's sarcoma, and 3 have chordoma. The median age was 24 years (range, 16–68 years), and the median number of prior regimens was 1 (range, 0–4). Until the final follow‐up, five patients obtained a partial response and while 24 achieved stable disease. The ORR in all patients was 10.4%, and the median PFS was 4.6 months, with a progression‐free rate (PFR) at 3 months and 6 months of 72.9% and 35.4%, respectively. The ORR and median PFS varied much among tumor subtypes. The most frequent grade 3–4 adverse events (AEs) were pneumothorax, hand‐foot syndrome, cholesterol elevation, hypertriglyceridemia, and fatigue. No patients died from anlotinib‐related AEs during the study period.

Conclusions

Anlotinib may show promising antitumor activity in unresectable or metastatic bone sarcoma. The ORR and median PFS of anlotnib are similar to those of other targeted drugs in different subtypes of sarcomas. The AEs were generally mild and tolerated well. Further studies of anlotinib in selected subtypes of bone sarcoma are needed.

A Pharmacological Analysis of the Activity and Failure of the Medical Treatment of High-Grade Osteosarcoma

Osteosarcomas (OSs) are a group of neoplasms originating from bone cells, usually presenting in three specific age groups: children, young adults, and the elderly. High-grade OS is an extremely malignant tumor mainly due to evolution into metastatic disease, usually in the lungs. Survival of these patients has improved since the 1980s thanks to close cooperation between oncologists, oncological surgeons and orthopedic surgeons. Unfortunately, no progress has been made in the last 30 years and new, more effective drugs are needed. This article reviews the biological and pharmacological basis of the treatment of OS. Models of clinical pharmacology of the active drugs, toxic effects and reasons for primary and secondary resistance to old and new drugs are discussed.

High Dose Ifosfamide in Relapsed and Unresectable High-Grade Osteosarcoma Patients: A Retrospective Series

Background: The evidence on high-dose ifosfamide (HD-IFO) use in patients with relapsed osteosarcoma is limited. We performed a retrospective study to analyze HD-IFO activity. Methods: Patients with osteosarcoma relapsed after standard treatment [methotrexate, doxorubicin, cisplatin +/- ifosfamide (MAP+/-I)] with measurable disease according to RECIST1.1 were eligible to ifosfamide (3 g/m2/day) continuous infusion (c.i.) days 1-5 q21d. RECIST1.1 overall response rate (ORR) (complete response (CR) + partial response (PR)), progression-free survival at 6-month (6m-PFS), duration of response (DOR), and 2-year overall survival (2y-OS) were assessed. PARP1 expression and gene mutations were tested by immunohistochemistry and next-generation sequencing. Results: 51 patients were included. ORR was 20% (1 CR + 9 PR). Median DOR was 5 months (95%CI 2-7). Median PFS, 6m-PFS, OS, and 2y-OS were 6 months (95%CI 4-9), 51%, 15 months (10-19), and 30%, respectively. A second surgical complete remission (CR2) was achieved in 26 (51%) patients. After multivariate analysis, previous use of ifosfamide (HR 2.007, p = 0.034) and CR2 (HR 0.126, p < 0.001) showed a significant correlation with PFS and OS, respectively. No significant correlation was found between outcomes and PARP1 or gene mutations. Conclusions: HD-IFO should be considered as the standard first-line treatment option in relapsed osteosarcoma and control arm of future trial in this setting.