Intra-tumor AvidinOX allows efficacy of low dose systemic biotinylated Cetuximab in a model of head and neck cancer

Abstract

For locally advanced and metastatic head and neck squamous cell carcinoma (HNSCC), the current clinical use of Cetuximab in chemo/radiotherapy protocols is often associated to severe systemic toxicity. Here we report in vitro data in human FaDu pharynx SCC cells, showing that inactive concentrations of biotinylated Cetuximab (bCet) become active upon anchorage to AvidinOX on the surface of tumor cells. AvidinOX-anchored bCet induces apoptosis and DNA damage as well as specific inhibition of signaling, degradation and abrogation of nuclear translocation of EGFR. In the mouse model of FaDu cancer, we show that intra-tumor injection of AvidinOX allows anti-tumor activity of an otherwise inactive, intraperitoneally delivered, low dose bCet. Consistently with in vitro data, in vivo tumor inhibition is associated to induction of apoptosis, DNA damage and reduced angiogenesis. AvidinOX is under clinical investigation for delivering radioactive biotin to inoperable tumors (ClinicalTrials.gov NCT02053324) and present data support its use for the local treatment of HNSCC in combination with systemic administration of low dose bCet.

Therapeutic efficacy of intra‑tumor AvidinOX and low systemic dose biotinylated cetuximab, with and without cisplatin, in an orthotopic model of head and neck cancer

“…The present work confirms and extends data from a previous study that showed the efficacy of using AvidinOX in mice bearing subcutaneous tumor xenografts treated with systemic low doses of bCet (13). The current study demonstrated that this therapeutic approach is also effective in an orthotopic model (tongue xenograft) and that efficacy can be further improved by adding a low dose of cisplatin to the treatment protocol.…”

“…1A confirm results obtained in a previous study using FaDu subcutaneous tumor xenografts, which demonstrated the anti-tumor efficacy of low dose bCet in AvidinOX-treated tumors. These results are supported by in vitro data indicating that AvidinOX-anchored bCet causes induction of EGFR degradation, inhibition of EGFR nuclear translocation and downstream signaling, plus upregulation of pro-apoptotic and cell damage markers (13). In the current study, the tumor growth inhibition of bCet was further improved by additional administration of low dose cisplatin; in fact, tumor masses treated with AvidinOX in mice receiving low doses of intraperitoneal bCet and cisplatin were significantly smaller than the tumor masses of mice treated with AvidinOX+bCet, or bCet+cisplatin.…”

“…There is a need to develop local treatments for cancer lesions that are derived from or reside within tissues/organs that are very different in terms of stromal composition, vascularization, density and other features. AvidinOX has been previously shown to form Schiff's bases with proteins in a variety of tissues and in several animal species (7)(8)(9)(10)(11)(12)(13). Long tissue residence of AvidinOX is also currently being confirmed in human patients with liver metastases and other inoperable tumor lesions as indicated by selective and consistent uptake of intravenous 177 Lu-ST2210 administered 1 and up to 15 days after intra-tumor AvidinOX (ClinicalTrials.gov NCT02053324 and NCT03188328, data not shown).…”

“…AvidinOX ® (registered brand of Alfasigma S.p.A., Rome, Italy) was prepared according to previously described methods (13) and the protein solution (3.0 mg/ml in acetate buffer, pH 5.5) was stored at -80˚C until use. Cetuximab (Erbitux ® ; Merck KGaA, Darmstadt, Germany) was biotinylated and controlled as previously described (12).…”

“…We recently described a novel method that allows suboptimal doses of biotinylated agents to become effective therapies in models of HNC. The treatment is based on the intra-tumor injection of AvidinOX, an oxidized avidin derivative that exhibits the distinctive property of forming Schiff's bases with tissue proteins (7)(8)(9)(10)(11), followed by systemically administered radioactive biotin (12) or biotinylated cetuximab (bCet) (13). In the present study, we show that the injection of AvidinOX into FaDu pharynx squamous cell carcinoma cells xenografted in the mouse tongue increases the anti-tumor activity of a suboptimal bCet dose administered intraperitoneally after 24 h. The data also indicate that the treatment can be repeated at least twice, 1 week apart, and that the therapeutic efficacy could be further improved by including a low dose of cisplatin in the protocol.…”