Phase 2 study for nonmetastatic extremity high-grade osteosarcoma in pediatric and adolescent and young adult patients with a risk-adapted strategy based on ABCB1/P-glycoprotein expression: An Italian Sarcoma Group trial (ISG/OS-2).

BACKGROUND: According to retrospective osteosarcoma series, ABCB1/P-glycoprotein (Pgp) overexpression predicts for poor outcomes. A prospective trial to assess a risk-adapted treatment strategy using mifamurtide in Pgp+ patients was performed. METHODS: This was a phase 2, multicenter, uncontrolled trial including patients 40 years old or younger with nonmetastatic extremity high-grade osteosarcoma stratified according to Pgp expression. All patients received high-dose methotrexate, doxorubicin, and cisplatin (MAP) preoperatively. In Pgp+ patients, mifamurtide was added postoperatively and combined with MAP for a good histologic response (necrosis ≥ 90%; good responders [GRs]) or with high-dose ifosfamide (HDIFO) at 3 g/m2 /d on days 1 to 5 for a histologic response < 90% (poor responders [PRs]). Pgp- patients received MAP postoperatively. After an amendment, the cumulative dose of methotrexate was increased from 60 to 120 g/m2 (from 5 to 10 courses). The primary end point was event-free survival (EFS). A postamendment analysis was performed. RESULTS: In all, 279 patients were recruited, and 194 were included in the postamendment analysis: 70 (36%) were Pgp-, and 124 (64%) were Pgp+. The median follow-up was 51 months. For Pgp+ patients, 5-year EFS after definitive surgery (null hypothesis, 40%) was 69.8% (90% confidence interval [CI], 62.2%-76.2%): 59.8% in PRs and 83.7% in GRs. For Pgp- patients, the 5-year EFS rate was 66.4% (90% CI, 55.6%-75.1%). CONCLUSIONS: This study showed that adjuvant mifamurtide, combined with HDIFO for a poor response to induction chemotherapy, could improve EFS in Pgp+ patients. Overall, the outcomes compared favorably with previous series. Mifamurtide and HDIFO as salvage chemotherapy are worth further study.

The addition of the immunomodulator mifamurtide to adjuvant chemotherapy for early osteosarcoma: a retrospective analysis.

BACKGROUND: Current treatment recommendations for high grade non-metastatic osteosarcoma include perioperative chemotherapy and surgery. Despite this intensive protocol, approximately 40% of patients will relapse. The addition of the immunomodulator mifamurtide to adjuvant cytotoxic chemotherapy was associated with a significant improvement in 6-year overall survival (OS) in young patients with resectable osteosarcoma, leading to its approval in Europe and other countries. Very limited real-world data are reported on its use. METHODS: We retrospectively evaluated data from osteosarcoma patients who received mifamurtide in the adjuvant setting. Data were obtained from medical records in 2 high-volume bone sarcoma centers. The aim of this study was to collect real-world data on mifamurtide safety and efficacy in Greece. RESULTS: We identified 15 patients with completely resected osteosarcoma who received mifamurtide from September 2015 to January 2020. Median age at diagnosis was 24 years old (16-76). Osteosarcoma arose in the lower extremities (n = 12), in the upper extremities (n = 2) or in the ilium (n = 1). The majority of patients (n = 13) received cisplatin/doxorubicin/methotrexate as perioperative chemotherapy and the remaining patients cisplatin/doxorubicin. After a median follow-up of 46.9 months (range, 32.8-61.1), the median recurrence-free survival was 58.7 months (range, 18.5-98.8) and the median OS 64.1 months (range, 25.6-102.6). Except for fever and chills, the only adverse event probably related to mifamurtide was pericarditis (n = 1). CONCLUSIONS: Mifamurtide was well tolerated in a Greek osteosarcoma population, including patients older than 30 years. The small sample size and the non-comparative design do not allow drawing conclusions on the drug benefit in terms of survival.

Liposomal Formulations to Modulate the Tumour Microenvironment and Antitumour Immune Response.

Tumours are complex systems of genetically diverse malignant cells that proliferate in the presence of a heterogeneous microenvironment consisting of host derived microvasculature, stromal, and immune cells. The components of the tumour microenvironment (TME) communicate with each other and with cancer cells, to regulate cellular processes that can inhibit, as well as enhance, tumour growth. Therapeutic strategies have been developed to modulate the TME and cancer-associated immune response. However, modulating compounds are often insoluble (aqueous solubility of less than 1 mg/mL) and have suboptimal pharmacokinetics that prevent therapeutically relevant drug concentrations from reaching the appropriate sites within the tumour. Nanomedicines and, in particular, liposomal formulations of relevant drug candidates, define clinically meaningful drug delivery systems that have the potential to ensure that the right drug candidate is delivered to the right area within tumours at the right time. Following encapsulation in liposomes, drug candidates often display extended plasma half-lives, higher plasma concentrations and may accumulate directly in the tumour tissue. Liposomes can normalise the tumour blood vessel structure and enhance the immunogenicity of tumour cell death; relatively unrecognised impacts associated with using liposomal formulations. This review describes liposomal formulations that affect components of the TME. A focus is placed on formulations which are approved for use in the clinic. The concept of tumour immunogenicity, and how liposomes may enhance radiation and chemotherapy-induced immunogenic cell death (ICD), is discussed. Liposomes are currently an indispensable tool in the treatment of cancer, and their contribution to cancer therapy may gain even further importance by incorporating modulators of the TME and the cancer-associated immune response.

Immune Therapy for Sarcomas.

Absolute lymphocyte count (ALC) recovery rapidly occurring at 14 days after start of chemotherapy for osteosarcoma and Ewing sarcoma is a good prognostic factor. Conversely, lymphopenia is associated with significantly decreased sarcoma survival. Clearly, the immune system can contribute towards better survival from sarcoma. This chapter will describe treatment and host factors that influence immune function and how effective local control and systemic interventions of sarcoma therapy can cause inflammation and/or immune suppression but are currently the standard of care. Preclinical and clinical efforts to enhance immune function against sarcoma will be reviewed. Interventions to enhance immune function against sarcoma have included regional therapy (surgery, cryoablation, radiofrequency ablation, electroporation, and radiotherapy), cytokines, macrophage activators (mifamurtide), vaccines, natural killer (NK) cells, T cell receptor (TCR) and chimeric antigen receptor (CAR) T cells, and efforts to decrease inflammation. The latter is particularly important because of new knowledge about factors influencing expression of checkpoint inhibitory molecules, PD1 and CTLA-4, in the tumor microenvironment. Since these molecules can now be blocked using anti-PD1 and anti-CTLA-4 antibodies, how to translate this knowledge into more effective immune therapies in the future as well as how to augment effectiveness of current interventions (e.g., radiotherapy) is a challenge. Barriers to implementing this knowledge include cost of agents that release immune checkpoint blockade and coordination of cost-effective outpatient sarcoma treatment. Information on how to research clinical trial eligibility criteria and how to access current immune therapy trials against sarcoma are shared, too.

Lifetime effectiveness of mifamurtide addition to chemotherapy in nonmetastatic and metastatic osteosarcoma: a Markov process model analysis.

The mortality and progression rates in osteosarcoma differ depending on the presence of metastasis. A decision model would be useful for estimating long-term effectiveness of treatment with limited clinical trial data. The aim of this study was to explore the lifetime effectiveness of the addition of mifamurtide to chemotherapy for patients with metastatic and nonmetastatic osteosarcoma. The target population was osteosarcoma patients with or without metastasis. A Markov process model was used, whose time horizon was lifetime with a starting age of 13 years. There were five health states: disease-free (DF), recurrence, post-recurrence disease-free, post-recurrence disease-progression, and death. Transition probabilities of the starting state, DF, were calculated from the INT-0133 clinical trials for chemotherapy with and without mifamurtide. Quality-adjusted life-years (QALY) increased upon addition of mifamurtide to chemotherapy by 10.5 % (10.13 and 9.17 QALY with and without mifamurtide, respectively) and 45.2 % (7.23 and 4.98 QALY with and without mifamurtide, respectively) relative to the lifetime effectiveness of chemotherapy in nonmetastatic and metastatic osteosarcoma, respectively. Life-years gained (LYG) increased by 10.1 % (13.10 LYG with mifamurtide and 11.90 LYG without mifamurtide) in nonmetastatic patients and 42.2 % (9.43 LYG with mifamurtide and 6.63 LYG without mifamurtide) in metastatic osteosarcoma patients. The Markov model analysis showed that chemotherapy with mifamurtide improved the lifetime effectiveness compared to chemotherapy alone in both nonmetastatic and metastatic osteosarcoma. Relative effectiveness of the therapy was higher in metastatic than nonmetastatic osteosarcoma over lifetime. However, absolute lifetime effectiveness was higher in nonmetastatic than metastatic osteosarcoma.

Pharmacokinetics and pharmacodynamics of liposomal mifamurtide in adult volunteers with mild or moderate renal impairment.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics following a single dose of liposomal mifamurtide (L-MTP-PE, MEPACT(®)) in adult subjects with mild (calculated creatinine clearance [CLcr ] of 50-80 ml min(-1)) or moderate (CLcr 30-50 ml min(-1)) renal impairment in comparison with age-, weight- and gender-matched healthy subjects with normal renal function (CLcr >80 ml min(-1)). METHODS: Subjects received a 4 mg dose of liposomal mifamurtide via 1 h intravenous infusion. Blood samples were collected over 72 h for analysis of plasma pharmacokinetics of total and non-liposome-associated (free) mifamurtide and assessment of pharmacodynamics (changes in serum interleukin-6 [IL-6], tumour necrosis factor-α [TNF-α], C-reactive protein [CRP]). RESULTS: Thirty-three subjects were enrolled: nine with mild renal impairment, eight with moderate renal impairment and 16 healthy subjects. Geometric mean (%CV) AUCinf for total mifamurtide was 89.5 (58.1), 94.8 (27.8), 85.1 (29.0), 95.4 (18.1) nM h in the mild renal impairment, mild-matched healthy subject, moderate renal impairment and moderate-matched healthy subject groups, respectively. Mifamurtide clearance was not correlated with CLcr, estimated glomerular filtration rate or iohexol clearance (all r(2) < 0.01). AUCinf of free mifamurtide was similar across the renal function groups. There were no readily apparent differences in serum pharmacodynamic effect parameters (baseline-adjusted AUEClast for IL-6 and TNF-α and Emax for CRP) between the renal function groups. No subjects reported grade ≥3 or serious adverse events. CONCLUSIONS: Mild or moderate renal impairment does not alter the clinical pharmacokinetics or pharmacodynamics of mifamurtide. No dose modifications appear necessary for these patients based on clinical pharmacologic considerations.

Pharmacokinetics and pharmacodynamics of liposomal mifamurtide in adult volunteers with mild or moderate hepatic impairment.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics after a single dose of liposomal mifamurtide (liposomal muramyl tripeptide phospatidyl ethanolamine; MEPACT(®)) in adult subjects with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment in comparison with age-, weight- and sex-matched healthy subjects with normal hepatic function. METHODS: Subjects received a 4 mg dose of liposomal mifamurtide via 1 h intravenous infusion. Blood samples were collected over 72 h for pharmacokinetic and pharmacodynamic assessments (changes in serum interleukin-6, tumour necrosis factor-α and C-reactive protein). RESULTS: Thirty-seven subjects were enrolled: nine with mild hepatic impairment, eight with moderate hepatic impairment and 20 matched healthy subjects. Geometric least-square mean ratios of total mifamurtide AUCinf for the mild hepatic impairment and moderate hepatic impairment groups vs. matched healthy subjects were 105% (90% confidence interval, 83.6-132%) and 119% (90% confidence interval, 94.1-151%), respectively, which are below the protocol-specified threshold (150%) to require development of dose-modification recommendations. Pharmacodynamic parameters for changes in serum interleukin-6 and tumour necrosis factor-α concentrations were generally similar across hepatic function groups. Mifamurtide-induced increases in serum C-reactive protein were attenuated in the moderate hepatic impairment group, consistent with the liver being the major organ of C-reactive protein synthesis. No grade ≥3 adverse events were seen in subjects administered mifamurtide (4 mg). CONCLUSIONS: These results support the conclusion that mild or moderate hepatic impairment does not produce clinically meaningful effects on the clinical pharmacokinetics or pharmacodynamics of mifamurtide; no dose modifications are needed in these special patient populations based on clinical pharmacological considerations.

NICE's selective application of differential discounting: ambiguous, inconsistent, and unjustified.

The National Institute for Health and Clinical Excellence (NICE) recently recommended differential discounting of costs and health effects in the economic appraisal of health care interventions in certain circumstances. The recommendation was published in an amendment to NICE's Guide to the Methods of Technology Appraisal. The amendment states that differential discounting should be applied where "treatment effects are both substantial in restoring health and sustained over a very long period (normally at least 30 years)." Renewed interest in differential discounting from NICE is welcome; however, the recommendation's selective application of differential discounting raises a number of concerns. The stated criteria for applying differential discounting are ambiguous. The rationale for the selective application of differential discounting has not been articulated by NICE and is questionable. The selective application of differential discounting leads to several inconsistencies, the most concerning of which is the lower valuation of health gains for those with less than 30 years remaining life expectancy, which can be interpreted as age discrimination. Furthermore, the discount rates chosen by NICE do not appear to be informed by recent advances in the theoretical understanding of differential discounting. NICE's apparent motivation for recommending differential discounting was to ensure a favorable cost-effectiveness ratio for a pediatric oncology drug. While flexibility may be appropriate to allow some interventions that exceed conventional cost-effectiveness thresholds to be adopted, the selective adjustment of appraisal methods is problematic and without justification.

Mifamurtide in metastatic and recurrent osteosarcoma: a patient access study with pharmacokinetic, pharmacodynamic, and safety assessments.

PURPOSE: This non-randomized, patient-access protocol, assessed both safety and efficacy outcomes following liposomal muramyl-tripeptide-phosphatidylethanolamine (L-MTP-PE; mifamurtide) in patients with high-risk, recurrent and/or metastatic osteosarcoma. METHODS: Patients received mifamurtide 2 mg/m(2) intravenously twice-weekly ×12 weeks, then weekly ×24 weeks with and without chemotherapy. Serum concentration-time profiles were collected. Adverse events within 24 hours of drug administration were classified as infusion-related adverse events (IRAE); other AEs and overall survival (OS) were assessed. RESULTS: The study began therapy in January 2008; the last patient completed therapy in October 2012. Two hundred five patients were enrolled; median age was 16.0 years and 146/205 (71%) had active disease. Mifamurtide serum concentrations declined rapidly in the first 30 minutes post-infusion, then in a log-linear manner 2-6 hours post-dose; t1/2 was 2 hours. There were no readily apparent relationships between age and BSA-normalized clearance, half-life, or pharmacodynamic effects, supporting the dose of 2 mg/m(2) mifamurtide across the age range. Patients reported 3,679 IRAE after 7,482 mifamurtide infusions. These were very rarely grade 3 or 4 and most commonly included chills + fever or headache + fatigue symptom clusters. One- and 2-year OS was 71.7% and 45.9%. Patients with initial metastatic disease or progression approximated by within 9 months of diagnosis (N = 40) had similar 2-year OS (39.9%) as the entire cohort (45.9%) CONCLUSIONS: Mifamurtide had a manageable safety profile; PK/PD of mifamurtide in this patient access study was consistent with prior studies. Two-year OS was 45.9%. A randomized clinical trial would be required to definitively determine impact on patient outcomes.

Chondrosarcoma Co-Culture 3D Model─An Insight to Evaluate Drugs Acting on TAMs.

Chondrosarcoma (CHS), also known as malignant cartilage tumors, is the second most common bone cancer after osteosarcoma. This tumor is particularly chemo- and radioresistant, and the only therapeutic alternative is surgery with wide margins. The tumor immune microenvironment reveals an infiltration of tumor-associated macrophages (TAMs) sometimes approaching 50% of the tumor mass, mainly differentiated into M2-like phenotype and correlated with poor prognosis and metastasis. Thus, macrophage-targeting therapies could have an interest in the management of CHS. To evaluate these strategies, we propose here the development of a three-dimensional (3D) tumoroid co-culture model between two human CHS cell lines (JJ012 and CH2879) and a human leukemia monocytic cell line (THP-1) in a methylcellulose matrix. These two models were compared to the in vivo xenograft models in terms of macrophage phenotypes, proteoglycans, MMP-9, and COX-2 expression. Finally, mifamurtide, an immunomodulator acting on TAMs, was evaluated on the most in vitro relevant model: 3D co-culture CH2879 model. Our results showed that it is now possible to develop 3D models that very accurately mimic what is found in vivo with the possibility of evaluating treatments specific to a tumor cell component.

Blockade of IL-10 Signaling Ensures Mifamurtide Efficacy in Metastatic Osteosarcoma.

Osteosarcoma (OS) is the most common primary malignancy of the bone, highly aggressive and metastasizing, and it mainly affects children and adolescents. The current standard of care for OS is a combination of surgery and chemotherapy. However, these treatment options are not always successful, especially in cases of metastatic or recurrent osteosarcomas. For this reason, research into new therapeutic strategies is currently underway, and immunotherapies have received considerable attention. Mifamurtide stands out among the most studied immunostimulant drugs; nevertheless, there are very conflicting opinions on its therapeutic efficacy. Here, we aimed to investigate mifamurtide efficacy through in vitro and in vivo experiments. Our results led us to identify a new possible target useful to improve mifamurtide effectiveness on metastatic OS: the cytokine interleukin-10 (IL-10). We provide experimental evidence that the synergic use of an anti-IL-10 antibody in combination with mifamurtide causes a significantly increased mortality rate in highest-grade OS cells and lower metastasis in an in vivo model compared with mifamurtide alone. Overall, our data suggest that mifamurtide in combination with an anti-IL-10 antibody could be proposed as a new treatment protocol to be studied to improve the outcomes of OS patients.

State-of-the-art, approved therapeutics for the pharmacological management of osteosarcoma.

Introduction: Advances in the treatment of osteosarcoma (OS) came in the mid-1970s, when adding chemotherapy to surgery significantly improved patient survival. OS outcomes have since plateaued, however, despite exhaustive clinical investigations.Area covered: This review focuses on the most significant recent results of trials (in phases II and III) on localized and metastatic/relapsing OS and offers an overview of new targeted drugs.Expert opinion: Recent findings confirm the MAP (methotrexate, doxorubicin, and cisplatin) regimen as the gold standard for OS patients, also in metastatic cases, and the inefficacy of augmenting or modifying chemotherapy in poor responder patients. Immunotherapy and several tyrosine kinase inhibitors seem to be effective and promising in the treatment of OS. Optimizing the use of active drugs available by personalizing chemotherapies might prove important in the future. We urgently need bench-to-bedside research on OS. This will need to involve the extensive sequencing and immunoprofiling of all resected tumor tissue to find new therapeutic agents, especially for relapsing/metastatic patients. The low incidence of OS, its genomic complexity, and differences within and between tumors combine to complicate efforts to elucidate the biology of this disease. This means that we need to pool the resources of different groups studying OS and support translational research.

The role of tumor-associated macrophages in osteosarcoma progression - therapeutic implications.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor. Compared with previous treatment modalities, such as amputation, more recent comprehensive treatment modalities based on neoadjuvant chemotherapy combined with limb salvage surgery have improved the survival rates of patients. Osteosarcoma treatment has, however, not further improved in recent years. Therefore, attention has shifted to the tumor microenvironment (TME) in which osteosarcoma cells are embedded. Therapeutic targets in the TME may be key to improving osteosarcoma treatment. Tumor-associated macrophages (TAMs) are the most common immune cells within the TME. TAMs in osteosarcoma may account for over 50% of the immune cells, and may play important roles in tumorigenesis, angiogenesis, immunosuppression, drug resistance and metastasis. Knowledge on the role of TAMs in the development, progression and treatment of osteosarcoma is gradually improving, although different or even opposing opinions still remain. CONCLUSIONS: TAMs may participate in the malignant progression of osteosarcoma through self-polarization, the promotion of blood vessel and lymphatic vessel formation, immunosuppression, and drug resistance. Besides, various immune checkpoint proteins expressed on the surface of TAMs, such as PD-1 and CD47, provide the possibility of the application of immune checkpoint inhibitors. Several clinical trials have been carried out and/or are in progress. Mifamotide and the immune checkpoint inhibitor Camrelizumab were both found to be effective in prolonging progression-free survival. Thus, TAMs may serve as attractive therapeutic targets. Targeting TAMs as a complementary therapy is expected to improve the prognosis of osteosarcoma. Further efforts may be made to identify potential beneficiaries of TAM-targeted therapies.

Improved osteosarcoma survival with addition of mifamurtide to conventional chemotherapy - Observational prospective single institution analysis.

PURPOSE: Conventional osteosarcoma is an orphan disease. Current treatment approaches include combining a three drug chemotherapy schedule and surgery. The 3- and 5-year event-free survival (EFS) in localized disease is roughly 65 and 60%, respectively. The registration study of mifamurtide reported survival benefit, but some methodological controversies have been insufficient for FDA market authorization in contrast to EMA. METHODS: prospective single centre survival analysis of a mifamurtide addition to conventional therapy in 23 patients over a 5.5 year enrolment period is reported and compared to a historical control of 26 patient with localized disease. Bias arising from observational methodology was addressed using Landmark analysis and time-dependent Cox models. Blood count dynamics were analysed during the treatment. RESULTS: The adverse event profile was as expected with no dose limiting toxicities. There were no local relapses observed, one patient died in the first complete remission due to doxorubicin cardiotoxicity, one patient had pulmonary metastatic relapse. The observed 3- and 5-year EFS was 87.4% (CI 72.4-100%) and 87.4% (CI 72.4-100%), progression free survival (PFS) was 92.9% (CI 80.3-100%) and 92.9% (CI 80.3-100%), overall survival was 94.1% (CI 83.6-100) and 80.7% (CI 58.3-100), respectively. Comparison to the historical control showed statistically significant better PFS for mifamurtide patients (Landmark analysis; p = 0.044). Risk of progression was 5-times lower for the mifamurtide group (Cox model; HR 0.21, p = 0.136). Only subtle differences in lymphocyte counts were observed across treatment. CONCLUSION: the PFS benefit of mifamurtide is reported herein. The addition of mifamurtide could be considered as a best treatment option for localized osteosarcoma.

Muramyl Tripeptide Plus Chemotherapy Reduces Metastasis in Non-Metastatic Osteosarcoma: A Single-Center Experience.

BACKGROUND: The immunomodulator mifamurtide plus a chemotherapy regimen has been shown to significantly improve the outcome in non-metastatic osteosarcoma patients. We report the results of the addition of mifamurtide to chemotherapy in newly diagnosed patients with osteosarcoma. METHODS: A total of 36 children with osteosarcoma without detectable metastasis were treated between November 2010 and April 2018 at the Ankara University Department of Pediatric Oncology. Mifamurtide was added to the chemotherapy regimen in 17 patients while the remaining 19 did not receive mifamurtide. The probabilities of metastasis and overall survival were compared between the groups. RESULTS: The 43-month survival rate was 87.5% and 89.9% in the patients who received and did not receive mifamurtide, respectively (p=0.65). Common side effects of mifamurtide were chills and fever. The addition of mifamurtide in the high-risk group with ≤95% necrosis tended to decrease the probability of distant metastasis (36.4% vs. 58.3%) (p=0.39). The time to metastasis in the group with positive surgical margins (4 months in one patient in the non-mifamurtide group, 7 and 20 months in the mifamurtide group) was also longer in the mifamurtide group. During the 43-month follow up period, median time to metastasis was longer in the mifamurtide group (20 vs. 5 months). In addition, mifamurtide plus chemotherapy decreased the risk of metastasis in the cases with primary site relapse. CONCLUSIONS: The addition of mifamurtide to chemotherapy might improve event-free survival by decreasing the probability of distant metastasis in bad histologic responders, and also by increasing the time to distant metastasis in the surgical margin positive group. Additional clinical studies are necessary to determine the long-term effects of mifamurtide on metastatic disease.
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Type 4 hypersensitivity development in a case due to mifamurtide.

BACKGROUND: This report aims to discuss the mechanism of pleural and pericardial effusion related to mifamurtide which is an immunological agent used as adjuvant chemotherapy in osteosarcoma. CASE: Mifamurtide (2 mg/m < sup > 2 < /sup > ) and European and American Osteosarcoma Studies (EURAMOS) protocol were used together intravenously after complete surgical resection. No side effects occurred except for fever after the first dose. However, pleural, pericardial effusion, and splenic nodule formation began 11 months after discontinuation of mifamurtide treatment. Pleural biopsy revealed a type 4 hypersensitivity reaction. We treated the patient with 1,5 mg per day colchicine. Pericardial effusion attacks and nodules in the spleen disappeared. The patient had a mild pleural effusion attack which has not yet repeated. CONCLUSION: Mifamurtide, which activates macrophages, can also activate immunity with a stand by effect and cause a hypersensitivity reaction.

Mifamurtide and TAM-like macrophages: effect on proliferation, migration and differentiation of osteosarcoma cells.

Tumor-associated macrophages and their alternative activation states together with cytokines and growth factors trapped in tumor microenvironment contribute to the progression of OS. In contrast to other tumor types, M2 polarized macrophages, reduce metastasis and improve survival in osteosarcoma patients. Mifamurtide is an immunomodulatory drug given together with standard adjuvant chemotherapy in high-grade osteosarcoma to improve outcome. Macrophages obtained from peripheral blood mononucleated cells of healthy donors and MG63 cells were cultured alone and together, and treated with Mifamurtide. We analyzed the effects of Mifamurtide on macrophage polarization and on MG63 proliferation, migration and differentiation, evaluating the expression of M1/M2 and osteoblast markers and molecules involved in metastasis and proliferation pathways. Our data suggest that Mifamurtide, switching macrophage polarization towards a TAM-like intermediate M1/M2 phenotype, may modulate the delicate balance between pro-inflammatory and immunomodulatory macrophage functions. Moreover, Mifamurtide may inhibit the cellular proliferation and induce the tumor cell differentiation, probably through the down regulation of pSTAT3, pAKT and IL-17R.

Delivery strategies for macromolecular drugs in cancer therapy.

With the development of biotherapy, biomacromolecular drugs have gained tremendous attention recently, especially in drug development field due to the sophisticated functions in vivo. Over the past few years, a motley variety of drug delivery strategies have been developed for biomacromolecular drugs to overcome the difficulties in the druggability, e.g., the instability and easily restricted by physiologic barriers. The application of novel delivery systems to deliver biomacromolecular drugs can usually prolong the half-life, increase the bioavailability, or improve patient compliance, which greatly improves the efficacy and potentiality for clinical use of biomacromolecular drugs. In this review, recent studies regarding the drug delivery strategies for macromolecular drugs in cancer therapy are summarized, mainly drawing on the development over the last five years.

Sarcome-13/OS2016 trial protocol: a multicentre, randomised, open-label, phase II trial of mifamurtide combined with postoperative chemotherapy for patients with newly diagnosed high-risk osteosarcoma.

INTRODUCTION: The controversial results on the mifamurtide efficacy associated with chemotherapy, issued from the American INT-0133-study, in localised osteosarcomas, and the underpowered analysis performed separately in metastatic patients, should be clarified to homogenise international use of this promising drug. The European Commission has granted a marketing authorisation to mifamurtide combined with postoperative chemotherapy in localised osteosarcomas but not in metastatic patients, while the Food and Drug Administration (FDA) has denied this authorisation. METHODS AND ANALYSIS: Sarcome-13/OS2016 trial is a multicentre randomised open-label phase II trial evaluating the survival benefit of mifamurtide administered during 36 weeks in combination with postoperative chemotherapy versus chemotherapy alone, in patients >2 and ≤50 years with newly diagnosed high-risk localised or metastatic osteosarcoma. The main objective is to evaluate the impact on event-free survival (EFS) of mifamurtide on intention-to-treat population. The secondary objectives are to evaluate the impact of mifamurtide on overall survival, to evaluate the feasibility and toxicity of the planned treatment, to correlate biology/immunology with the mifamurtide efficacy/toxicity. With a total of 126 enrolled patients and 51 events, the power is 80% if mifamurtide is associated with an 18% improvement of the 3-year EFS (52%vs70%, equivalent to an HR=0.55), with a one-sided logrank test alpha=10%. As relevant historical data are available (aggregate treatment effect from the INT-0133 trial and individual data from the control group of the Sarcome-09/OS2006 trial), a Bayesian analysis is also planned. ETHICS AND DISSEMINATION: This study was approved by the 'Comité de Protection des Personnes Ile de France I' (12/06/2018), complies with the Declaration of Helsinki and French laws and regulations, and follows the International Conference on Harmonisation E6 Guideline for Good Clinical Practice. The trial results, even if they are inconclusive, as well as biological ancillary studies will be presented at appropriate international congresses and published in international peer-review journals. TRIAL REGISTRATION NUMBER: EudraCT 2017-001165-24, NCT03643133.

L-MTP-PE and zoledronic acid combination in osteosarcoma: preclinical evidence of positive therapeutic combination for clinical transfer.

Osteosarcoma, the most frequent malignant primary bone tumor in pediatric patients is characterized by osteolysis promoting tumor growth. Lung metastasis is the major bad prognosis factor of this disease. Zoledronic Acid (ZA), a potent inhibitor of bone resorption is currently evaluated in phase III randomized studies in Europe for the treatment of osteosarcoma and Ewing sarcoma. The beneficial effect of the liposomal form of Muramyl-TriPeptide-Phosphatidyl Ethanolamine (L-mifamurtide, MEPACT®), an activator of macrophage populations has been demonstrated to eradicate lung metastatic foci in osteosarcoma. The objective of this study was to evaluate the potential therapeutic benefit and the safety of the ZA and L-mifamurtide combination in preclinical models of osteosarcoma, as a prerequisite before translation to patients. The effects of ZA (100 µg/kg) and L-mifamurtide (1 mg/kg) were investigated in vivo in xenogeneic and syngeneic mice models of osteosarcoma, at clinical (tumor proliferation, spontaneous lung metastases development), radiological (bone microarchitecture by microCT analysis), biological and histological levels. No interference between the two drugs could be observed on ZA-induced bone protection and on L-mifamurtide-induced inhibition of lung metastasis development. Unexpectedly, ZA and L-mifamurtide association induced an additional and in some cases synergistic inhibition of primary tumor progression. L-mifamurtide has no effect on tumor proliferation in vitro or in vivo, and macrophage population was not affected at the tumor site whatever the treatment. This study evidenced for the first time a significant inhibition of primary osteosarcoma progression when both drugs are combined. This result constitutes a first proof-of-principle for clinical application in osteosarcoma patients.