Dosage unit formulations of autologous dermal fibroblasts

Inventors

Maslowski, John M.

Assignees

Fibrocell Science Inc • Castle Creek Biosciences LLC

Abstract

Dosage units consist of an autologous cell therapy product composed of fibroblasts grown for each individual to be treated. The suspension of autologous fibroblasts, grown from a biopsy of each individual's own skin using current good manufacturing practices (CGMP), and standard tissue culture procedures, is supplied in vials containing cryopreserved fibroblasts or precursors thereof, having a purity of at least 98% fibroblasts and a viability of at least 85%, for administration of from one to six mL, preferably two mL, of cells at a concentration of from 1.0-2.0×107 cells/mL. When injected into the nasolabial fold wrinkles (creases on the sides of the nose that extend to the corners of the mouth), the autologous fibroblasts are thought to increase the synthesis of extracellular matrix components, including collagen, reducing the severity of these wrinkles. Dosage and timing of administration have been demonstrated to be critical to achieving clinically significant outcomes.

Core Innovation

The invention relates to a method of treating skin defects using an in vitro expanded autologous human fibroblast population that is cryopreserved, thawed, characterized, and injected. The method includes determining a total cell count of an autologous human fibroblast population of between 3.4×10^8 and 1×10^9 cells and freezing a sample in a cryopreservation medium comprising Iscove’s Modified Dulbecco’s Medium (IMDM) and dimethyl sulfoxide (DMSO) via a controlled rate freezing step process.

After thawing, the method determines that the thawed sample comprises at least 98% autologous human fibroblasts and that at least 85% of the thawed cells are viable after freezing and thawing. Viability is determined using a membrane-permeable dye and a membrane-impermeable dye combination, and the thawed cells are reactive with a cell surface marker for fibroblasts and not with a cell surface marker for keratinocyte cells.

The method includes injecting an effective amount of a frozen and thawed dosage formulation consisting essentially of between 1.0 and 2.7×10^7 cells/mL into the superficial papillary dermis of a site to be treated. The treatment is delivered in two or three treatments separated by five weeks plus or minus seven to ten days, and the dosage formulation does not comprise a structural filler.

The dosage formulation acts gradually to treat skin defects over time through tissue repair and regeneration, with dependent embodiments specifying particular skin defect types and detailed dose distributions and injection volumes.

Claims Coverage

The independent claim is clm-00001. It contains a coordinated set of four inventive features combining defined total starting cell count, controlled rate cryopreservation using IMDM and DMSO with a ramp program, post-thaw identity and viability acceptance thresholds using marker reactivity and permeable/impermeable dye viability, and injection of a frozen/thawed dosage formulation into the superficial papillary dermis without a structural filler, with specified dosing concentration, treatment cadence, and gradual tissue repair/regeneration action.

Across the independent claim and refinements, the coverage centers on injecting qualified, frozen-and-thawed autologous human fibroblasts into the superficial papillary dermis without a structural filler. The method ties together defined starting cell count, a controlled rate IMDM/DMSO cryopreservation process, acceptance thresholds for fibroblast identity and viability, and specified dosing concentration plus multi-session spacing, with dependent claims further constraining defect-specific dosing volumes, distributions, and injection targets.

Stated Advantages

Documented Applications