Results of previous study showed promising but short-lived activity of sorafenib in the treatment of patients with unresectable advanced and metastatic osteosarcoma. This treatment failure has been attributed to the mTOR pathway and might therefore be overcome with the addition of mTOR inhibitors. We aimed to investigate the activity of sorafenib in combination with everolimus in patients with inoperable high-grade osteosarcoma progressing after standard treatment. We did this non-randomised phase 2 trial in three Italian Sarcoma Group centres. We enrolled adults (≥18 years) with relapsed or unresectable osteosarcoma progressing after standard treatment (methotrexate, cisplatin, and doxorubicin, with or without ifosfamide). Patients received 800 mg sorafenib plus 5 mg everolimus once a day until disease progression or unacceptable toxic effects. The primary endpoint was 6 month progression-free survival (PFS). All analyses were intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01804374. We enrolled 38 patients between June 16, 2011, and June 4, 2013. 17 (45%; 95% CI 28-61) of 38 patients were progression free at 6 months. Toxic effects led to dose reductions, or short interruptions, or both in 25 (66%) of 38 patients and permanent discontinuation for two (5%) patients. The most common grade 3-4 adverse events were lymphopenia and hypophosphataemia each in six (16%) patients, hand and foot syndrome in five (13%), thrombocytopenia in four (11%), and fatigue, oral mucositis, diarrhoea, and anaemia each in two (5%). One patient (3%) had a grade 3 pneumothorax that required trans-thoracic drainage, and that recurred at the time of disease progression. This was reported as a serious adverse event related to the study drugs in both instances. No other serious adverse events were reported during the trial. There were no treatment-related deaths. Although the combination of sorafenib and everolimus showed activity as a further-line treatment for patients with advanced or unresectable osteosarcoma, it did not attain the prespecified target of 6 month PFS of 50% or greater. Italian Sarcoma Group.

Introduction: Cytokine-induced killer (CIK) cells are heterogeneous ex vivo-expanded T lymphocytes with mixed T-NK phenotype and endowed with a wide MHC-unrestricted antitumor activity. CIK cells can be expanded from peripheral blood mononuclear cells (PBMC) cultured with the timed addition of IFN-γ, Ab anti-CD3 and IL2. A consistent subset of mature CIK cells presents a CD3⁺CD56⁺ phenotype. The CD3⁺CD56⁺ cellular subset is the main responsible for the tumor-killing activity, mostly mediated by the interaction of NKG2D receptor with MHC-unrestricted ligands (MIC A/B; ULBPs) on tumor cells. Areas covered: In the present work, we described the biologic characteristics of CIK cells, focusing on those aspects that may favor their clinical translation. We reviewed preclinical data and analyzed reports from clinical trials. A specific paragraph is dedicated to future research perspectives in the field. Expert opinion: CIK cells represent a realistic new option in the field of cancer immunotherapy. Crucial issues, favoring their clinical translation, are the easy availability of large amounts of expanded CIK cells and their MHC-unrestricted tumor killing, potentially effective against many tumor types. Intriguing future perspectives and open challenges are the investigation of synergisms with other immunotherapy approaches, targeted therapies or even conventional chemotherapy.

Cytokine-induced killer (CIK) cells are a heterogeneous subset of ex-vivo expanded T lymphocytes which present a mixed T-NK phenotype and are endowed with a MHC-unrestricted antitumor activity. The main functional properties of CIK cells may address some of the main limitations that are currently preventing the successful clinical translation of adoptive immunotherapy strategies. Clinically adequate quantities of immune effectors, sufficient for multiple adoptive infusions, may be obtained based on their relatively easy and inexpensive ex-vivo expansion starting from peripheral blood mononuclear cells. The MHC-unrestricted tumor-killing is mainly based on the interaction between NKG2D molecules on CIK cells and MIC A/B or ULBPs molecules on tumor cells; it has been proved effective against several solid and hematological malignancies and does not require any HLA-restriction increasing the number of patients that might potentially benefit from such approach. Finally, CIK cells present a reduced alloreactivity across HLA-barriers with important clinical implications for their potential use as alternative to conventional Donor Lymphocyte Infusions after allogeneic hemopoietic cell transplant with a reduced risk of GVHD. In the present report we review the main functional characteristics of CIK cells discussing recent findings and future perspectives to improve their antitumor activity and potential clinical applications.

Donor-derived cytokine-induced killer (CIK) can be infused as adoptive immunotherapy after hematopoietic cell transplant (HCT). Promising results were recently reported in HLA-identical HCT, where mild grafts versus host (GVH) events were observed. To extend this strategy across major HLA barriers (e.g. HLA-haploidentical HCT), further studies on CIK cells' alloreactivity are needed. We hypothesized that alloreactivity and anti-tumor activity of CIK cells segregate within two different cell subsets and could consequently be separated according to CD56 and CD3 expression. We tested CIK cells expanded from seven patients who underwent HCT as treatment of metastatic colorectal cancer. We found that CIK cells maintained their alloreactivity across major HLA barriers when tested as bulk population; after CD56-positive selection, anti-tumor activity was restricted to the CD3+/CD56+ cell fraction and alloreactivity versus HLA-mismatched PBMC was restricted to the CD3+/CD56− cell fraction. Bulk CIK cells from engrafted patients did not exhibit alloreactivity in response to host- or donor-derived PBMC, confirming their low potential for GVH across minor HLA barriers. Moreover, we tested if CIK cells expanded from engrafted patients after HCT were as effective as donor-derived ones and could be considered as an alternative option. The expansion rate and tumor cell killing was comparable to that observed in sibling donors. In conclusion, depletion of CD3+/CD56− cells might reduce the risk of GVH without affecting the tumor-killing capacity and could help extending CIK infusions across major HLA barriers. Engrafted patients after HCT could also be considered as an effective alternative option to donor-derived CIK cells.

Despite intensive chemotherapy and surgery treatment, lung and bone metastasis develop in about 30% of patients with osteosarcoma. Mechanisms for this preferential metastatic behavior are largely unknown. We investigated the role of the chemokine receptor 4 (CXCR4)/stromal cell–derived factor 1 (SDF-1) system to drive the homing of osteosarcoma cells. We analyzed the expression of the CXCR4 and SDF-1 proteins on several osteosarcoma cell lines and the effects of SDF-1 on migration, adhesion, and proliferation of these cancer cells. In vitro assays showed that the migration of osteosarcoma cells expressing CXCR4 receptor follows an SDF-1 gradient and that their adhesion to endothelial and bone marrow stromal cells is promoted by SDF-1 treatment. Moreover, the production of matrix metalloproteinase-9 is increased after SDF-1 exposure. We finally proved in a mouse model our hypothesis of the CXCR4/SDF-1 axis involvement in the metastatic process of osteosarcoma cells. Development of lung metastasis after injection of osteosarcoma cells was prevented by the administration of a CXCR4 inhibitor, the T134 peptide. These data show a possible explanation for the preferential osteosarcoma metastatic development into the lung, where SDF-1 concentration is high, and suggest that molecular strategies aimed at inhibiting the CXCR4/SDF-1 pathway, such as small-molecule inhibitors or anti-CXCR4 antibodies, might prevent the dissemination of osteosarcoma cells.