PDGF and Becaplermin: The Growth Factor That Reached Approval

Platelet-derived growth factor is one of the first signals released when tissue is injured, and it is the basis of becaplermin (Regranex), an FDA-approved topical gel for diabetic foot ulcers. That approval makes PDGF unusual in this category, and the route it took is instructive.

This guide situates PDGF within the broader field of peptide therapy and is written for clinicians. It is clinical education, not medical advice, and nothing here should be read as a treatment recommendation or protocol.

What PDGF does

PDGF is stored in platelet alpha granules and released immediately upon platelet activation — making it one of the earliest signals present when tissue is injured and bleeding. It is also produced by macrophages, endothelial cells and fibroblasts.

Its principal actions are chemotaxis and proliferation of fibroblasts and smooth muscle cells. It recruits the cells that build granulation tissue and stimulates them to produce extracellular matrix. It also plays an essential role in vessel maturation by recruiting pericytes to newly formed vessels — the step that turns the leaky immature vasculature produced by VEGF alone into stable functional vessels.

That pericyte role is a direct illustration of why single-factor approaches to angiogenesis failed. Building a blood vessel is a relay, not a single instruction.

Becaplermin: the approved product

Becaplermin is recombinant human PDGF-BB formulated as a topical gel, approved for lower-extremity diabetic neuropathic ulcers extending into subcutaneous tissue or beyond with adequate blood supply.

The reason this succeeded where systemic growth factor therapy did not comes down to delivery. A chronic wound is accessible from the outside. The factor can be applied directly and repeatedly to exactly the tissue that needs it, at a controlled dose, without systemic exposure. The problem that defeated therapeutic angiogenesis — getting a sustained signal to the right place without dosing the whole body — simply does not arise.

Its labeling has a notable history. A boxed warning regarding increased mortality from malignancy in patients who used three or more tubes was added after post-marketing epidemiologic findings, then revised as further data accumulated and did not confirm the association. Current labeling should be consulted directly rather than recalled, as this has changed more than once.

Importantly, becaplermin is an adjunct. It is used alongside good wound care — debridement, offloading, infection control, and adequate perfusion — not instead of it. Applied to a wound that is infected, poorly perfused or not offloaded, it does not work.

The connection to platelet-rich plasma

PDGF's origin in platelets is the biological rationale behind platelet-rich plasma. Concentrating platelets concentrates the growth factors they release — PDGF prominent among them — and delivers them to the target tissue.

That rationale is sound as far as it goes. The complication is that PRP is not a standardized product: platelet concentration, leukocyte content, activation method and preparation protocol vary widely between systems and operators, which is a substantial part of why the clinical literature is so inconsistent across indications.

The distinction worth holding is between a characterized recombinant protein at a defined dose and a variable autologous preparation containing many factors at uncontrolled concentrations. Both may be reasonable; they are not the same kind of intervention.

Status and caution

Recombinant PDGF is approved only in the topical becaplermin formulation for its specified indication. There is no approved systemic PDGF product, and PDGF is not an established compounding substance for that purpose.

The general oncologic caution that applies to growth factors applies here. PDGF signaling is implicated in several malignancies and in fibrotic disease, and a factor that drives fibroblast proliferation is not one to introduce systemically without a compelling rationale.