Ionizing irradiation sterilization of bacterial minicell-based biopharmaceuticals and methods of use
Inventors
Giacalone, Matthew J. • Ward, Gary H.
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-10124024-B2
Publication Date
2018-11-13
Expiration Date
Abstract
Disclosed herein are methods of terminally sterilizing bacterial minicells or compositions comprising bacterial minicells by exposure to ionizing irradiation. Also disclosed are terminally sterilized bacterial minicells, pharmaceutical compositions comprising the bacterial minicells, and methods of use the bacterial minicells and pharmaceutical compositions.
Core Innovation
The disclosed invention relates to a method of producing a terminally sterilized composition of bacterial minicells for pharmaceutical use. The method comprises exposing a composition comprising a plurality of bacterial minicells to gamma irradiation. The strategy is directed to achieving sterility for pharmaceutical minicell compositions while maintaining bacterial minicell integrity and functional characteristics after irradiation.
The problem addressed is that terminal sterilization is needed for pharmaceutical minicell compositions, and it must overcome limitations associated with filtration-based sterilization. The document describes using gamma irradiation, including for formulations prepared and maintained as frozen suspension or frozen lyophile/lyophilized compositions. It further grounds sterility adequacy in USP <71> standards and specifies the version USP 38 NF 33.
The document reports that gamma irradiation can achieve USP <71> sterility while unexpectedly preserving minicell integrity, targeting function, potency, and bioactive payload activity. It describes maintained appearance/integrity, unchanged perfringolysin O (PFO) hemolytic activity, maintained in vitro cell-killing potency (EC50 overlap), and no loss of in vivo antitumor activity as shown by Kaplan-Meier survival after gamma irradiation. For targeted minicells, additional evaluation reports preserved antibody surface binding, doxorubicin retention, plasmid integrity (PCR), and potency after 25 kGy.
Claims Coverage
The independent claim covers terminal sterilization of a bacterial minicell pharmaceutical composition by gamma irradiation. Across the related claim set provided, the inventive coverage is refined with gamma irradiation dose range, sterility adequacy mapped to USP <71> under a specified version (USP 38 NF 33), and composition form and excipient/diluent and minicell biological features (invasin and PFO).
Terminally sterilized bacterial minicell pharmaceutical composition by gamma irradiation
Exposing a composition comprising a plurality of bacterial minicells to gamma irradiation to produce a terminally sterilized composition for pharmaceutical use.
Gamma irradiation dose range for terminal sterilization
Using gamma irradiation at a dose of about 5 kGy to about 40 kGy.
USP <71> sterilization adequacy under USP 38 NF 33
Using a gamma irradiation dose sufficient to sterilize the composition to conform to USP <71> standards under the version USP 38 NF 33.
Terminal sterilization using an approximately 25 kGy gamma irradiation dose
Carrying out the method using gamma irradiation at an approximate dose of about 25 kGy.
Pharmaceutical excipient and/or diluent included in the composition
The composition is a pharmaceutical composition comprising a pharmaceutically acceptable excipient, a pharmaceutically acceptable diluent, or both.
Minicells with invasin and/or perfringolysin O (PFO)
The bacterial minicells display invasin, comprise perfringolysin O (PFO), or both.
Overall, the claim coverage centers on producing terminally sterilized bacterial minicell pharmaceutical compositions by gamma irradiation, with refinements that specify a dose range, define sterilization adequacy by USP <71> (USP 38 NF 33), and limit the claimed context to particular composition components and minicell biological constituents including invasin and perfringolysin O (PFO).
Stated Advantages
Achieves USP <71> sterility for terminally sterilized bacterial minicell pharmaceutical compositions.
Unexpectedly preserves minicell integrity after gamma irradiation.
Preserves targeting function, potency, and bioactive payload activity after gamma irradiation.
Maintains PFO hemolytic activity after gamma irradiation.
Maintains in vitro cell-killing potency (EC50 overlap) after gamma irradiation.
Shows no loss of in vivo antitumor activity after gamma irradiation (Kaplan-Meier).
Preserves antibody surface binding for targeted minicells after irradiation.
Preserves doxorubicin retention, plasmid integrity (PCR), and potency after 25 kGy.
Documented Applications
Bacterial minicell-based biopharmaceuticals delivered as terminally sterilized pharmaceutical compositions, including frozen suspension and frozen lyophile/lyophilized formulations.
Minicells exhibiting invasin and/or perfringolysin O (PFO) as bioactive payload functionality used in sterile pharmaceutical contexts.
Targeted minicells (EGFR-1) evaluated for preserved antibody surface binding, doxorubicin retention, plasmid integrity (PCR), and potency after gamma irradiation.
In vivo evaluation using an orthotopic murine MB49 bladder cancer model to assess antitumor activity after gamma irradiation (Kaplan-Meier).
Interested in licensing this patent?