Heat Shock Protein 90 alpha (Hsp90α)
Hsp90α is used to accelerate healing of chronic skin ulcers. Hsp90α will help fill the unmet clinical needs of 7 million patients in the US with chronic wounds. Three major patient populations are diabetic patients with foot ulcers (4 million patients), elderly and chronically immobilized patients with pressure ulcers also known as bed sores (2.5 million patients), and patients with varicose ulcers (0.6 million patients). The current treatments for chronic wounds fail to decrease the progression of these wounds and the need for increasingly aggressive interventions.
Recombinant human Hsp90α 115-amino acid peptide was formulated into a gel form (rHuHSP90α-115) and is utilized as a topical drug for wound healing. Hsp90α (F-5 in figure) decreases healing time of chronic wounds from 35 days to 16 days in diabetic mouse models with one topical application.
Mechanisms of Action
Hsp90α is secreted naturally by epithelial cells when stressed or stimulated; Hsp90α promotes fibroblast, epithelial, and keratinocyte migration to the area. The stronger effect of Hsp90α was due to 3 properties not held by conventional growth factors: its ability to recruit both epidermal and dermal cells; the fact that its ability to promote dermal cell migration was not inhibited by TGF-β; and its ability to override the inhibitory effects of hyperglycemia on cell migration in diabetes.
Comparables in Market
Regranex (Becaplermin, a recombinant human PDGF-BB) is the currently only US FDA-approved growth factor therapy; it shows modest efficacy, is costly, and has the potential to cause cancer in patients. Hsp90α is an effective, safe, simple, and cost effective solution to heal chronic skin wounds, reduce patient suffering, and decrease long term health care costs.
The first indication we aim to develop Hsp90α for will be diabetic foot ulcers. It has also shown potential for accelerating recovery for burns, surgical operations, and other types of acute and chronic wounds.