In this Phase I proposal, we will demonstrate the ability to scale up the production of a lead liposomal formulation candidate of acylated, lipophilic rHuTNF. We will subject the bacterial recombinant protein to acylation with the N-hydroxysuccinimide ester of caprylic acid (C3) to achieve limited substitution (1.5 - 2 residues per TNF trimer). The identity and extent of substitution of the target amino groups in TNF will be established by a tryptic digestion/mass spectroscopy strategy. An optimal SUV formulation composed of DPPC, DSPC, and DSPE-PEG will be defined based on high binding to acylated TNF, high phase-transition temperature, and stability to storage under mock physiological conditions. When optimal conditions for TNF acylation and composition of SUVs have been determined, final formulation of liposomal lipophilic TNF will be conducted at a scale (> 20 mg TNF/1 gm lipid) appropriate for future preclinical evaluation. This feasibility study should facilitate compliance with quality control measures likely to be requested by the FDA in future pre- IND discussions.
