Summary:
In patients with diabetic foot ulcers, particularly those with peripheral artery disease, intramuscular human placenta-derived cells (PDA-002) significantly increased the rate of complete and sustained wound closure compared to placebo across three dose groups, with the highest efficacy seen at the 3 × 106 cell dose, though it was associated with no treatment-related serious adverse events.
| PICO | Description |
|---|---|
| Population | Adults with chronic diabetic foot ulcers, stratified by presence or absence of peripheral artery disease. |
| Intervention | Intramuscular injection of human placenta-derived stromal-like cells (PDA-002) administered at doses of 3 × 106, 10 × 106, and 30 × 106 cells. |
| Comparison | Placebo treatment given under similar conditions as the active intervention arms. |
| Outcome | The primary endpoint—complete wound closure within 3 months sustained for an additional 4 weeks—was most effectively achieved with the 3 × 106 cell dose in patients with peripheral artery disease (38.5% vs. 22.6% placebo). PDA-002 was well-tolerated with no treatment-related serious adverse events. |
Clinical Context
Diabetic foot ulcers are a leading cause of morbidity, hospitalisation and lower-limb amputation. Chronic hyperglycaemia impairs angiogenesis, immune function and extracellular-matrix remodelling, while coexisting peripheral artery disease (PAD) reduces perfusion and sharply lowers the likelihood of healing. Standard care — debridement, offloading, infection control and revascularisation where feasible — frequently fails in poorly perfused wounds, leaving a substantial unmet need. Placenta-derived stromal-like cells (PDA-002) are thought to secrete pro-angiogenic and immunomodulatory factors that could improve local perfusion and the wound microenvironment, and intramuscular delivery targets the ischaemic tissue bed rather than the ulcer surface alone. This phase 2 trial addresses the gap by testing a cell-based therapy specifically in the difficult-to-heal population, including patients with PAD.
Clinical Pearls
- Higher closure in PAD patients: At the 3 × 10⁶ cell dose, complete wound closure reached 38.5% versus 22.6% with placebo in patients with peripheral artery disease — the group with the greatest unmet need.
- Stringent primary endpoint: Success required complete closure within 3 months that was then sustained for a further 4 weeks, a more demanding measure than transient healing.
- Non-linear dose response: The lowest of the three doses (3 × 10⁶) appeared most effective, an unexpected pattern that complicates dose selection and warrants confirmation.
- Favourable safety signal: PDA-002 was well tolerated, with no treatment-related serious adverse events reported.
Practical Application
This remains an experimental, phase 2 intervention and is not part of routine diabetic foot ulcer care. Standard management — meticulous debridement, pressure offloading, infection control, glycaemic optimisation and vascular assessment with revascularisation where indicated — stays the foundation of treatment, and clinicians should not expect cell therapy to substitute for these measures. The most encouraging signal was confined to a subgroup of patients with peripheral artery disease at a single dose, so the results are hypothesis-generating rather than practice-changing. Should the therapy advance, it would most plausibly serve as an adjunct for poorly perfused, hard-to-heal ulcers managed in specialist centres. For now, the findings support further trials rather than clinical adoption.
Broader Evidence Context
Numerous adjuncts to standard wound care — bioengineered skin substitutes, recombinant growth factors, negative-pressure therapy and other cell-based products — have been studied in diabetic foot ulcers, generally yielding modest and inconsistent benefits, particularly in ischaemic wounds. Against that backdrop, a regenerative cell therapy showing improved closure specifically in PAD-affected patients is notable, since this subgroup is typically excluded from or fares worst in healing trials. The result is consistent with the broader hypothesis that pro-angiogenic strategies may help perfusion-limited wounds, but it does not yet match the evidence base supporting established care. Confirmation in adequately powered phase 3 trials would be required before guidelines could change.
Study Limitations
- This was a phase 2 trial, designed to explore efficacy and safety rather than to confirm benefit definitively.
- The key positive result came from a subgroup (patients with PAD) at one dose, raising the risk of a chance finding.
- The dose response was non-monotonic, with the lowest dose performing best, which is biologically difficult to interpret.
- Follow-up captured wound closure sustained for 4 weeks but not longer-term recurrence, amputation or limb-salvage outcomes.
- Sample sizes within the dose and PAD strata were likely small, limiting precision and generalisability.
Bottom Line
In this phase 2 trial, intramuscular placenta-derived cells improved sustained wound closure in diabetic foot ulcer patients, with the clearest benefit (38.5% vs 22.6%) seen at the lowest dose in those with peripheral artery disease and no treatment-related serious adverse events. The signal is promising for a hard-to-treat group, but the subgroup-level, non-linear findings are preliminary. Larger confirmatory trials are needed before placenta-derived cell therapy could be considered in routine practice.
Source: Richard Pollak, et al. “Human Placenta-Derived Cells (PDA-002) in Diabetic Foot Ulcer Patients With and Without Peripheral Artery Disease: A Phase 2 Multi-Center, Randomised, Double-Blind, Placebo-Controlled Trial.” Read article here.
