Antiangiogenic Agents

Pathological angiogenesis, the abnormal growth of new blood vessels, lies at the heart of many skin conditions. These range from congenital hemangiomas and vascular malformations, through chronic inflammatory diseases with a strong neovascular component (such as psoriasis and phymatous rosacea/rhinophyma), to hypertrophic scars, keloids and skin cancers (such as Kaposi sarcoma and melanoma).

Antiangiogenic agents include monoclonal antibodies, small-molecule tyrosine kinase inhibitors (TKIs) and immunomodulatory drugs. They act directly on the signaling pathways that drive endothelial cell growth, causing abnormal capillaries to regress and restoring a healthy balance to the skin's microcirculation. At Haute-Derma, antiangiogenic therapy is tailored closely to each patient. We favor topical and intralesional treatments to get the most effect in the diseased skin while keeping systemic toxicity to a minimum.

Biological Mechanisms and Pharmacodynamics

New vessel growth is a complex process driven by an imbalance between pro-angiogenic and anti-angiogenic factors in the tissue:

The VEGF/VEGFR signaling axis: Vascular endothelial growth factor A (VEGF-A) is the most potent stimulus for angiogenesis. When VEGF-A binds to VEGFR-1 and VEGFR-2 on the endothelial cell membrane, it triggers autophosphorylation of the intracellular tyrosine kinase domains. This signal drives endothelial cells to multiply, migrate and release matrix metalloproteinases (MMPs) that break down the basement membrane and form new capillary sprouts.
Neutralizing free VEGF (bevacizumab, ranibizumab): These monoclonal antibodies bind selectively to free VEGF-A in tissue fluid and stop it from reaching VEGFR-1 and VEGFR-2. This shuts down the whole endothelial growth cascade and pushes newly formed endothelial cells into apoptosis.
Multi-target intracellular tyrosine kinase inhibition (sunitinib, sorafenib, pazopanib): These small molecules cross the cell membrane and compete for the ATP-binding site in the catalytic domain of VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-beta and FGFR-1. Blocking several receptors at once prevents both the formation of new vessels and the stabilization of vessel walls.
Inhibiting production of pro-angiogenic factors (thalidomide, lenalidomide): Thalidomide reduces transcription of the genes encoding VEGF and basic fibroblast growth factor (bFGF) by interfering with nuclear factors, and it also inhibits endothelial cell chemotaxis.

Classes of Antiangiogenic Drugs Used in Dermatology

VEGF-neutralizing monoclonal antibodies: Bevacizumab (oral, intravenous infusion or intralesional injection) and ranibizumab. Used for Kaposi sarcoma and severe, progressive hemangiomas, and injected locally as part of combination treatment for resistant keloids.
Small-molecule multi-target tyrosine kinase inhibitors (TKIs): Sunitinib, sorafenib, pazopanib and axitinib. Mainly used for advanced skin cancers (metastatic melanoma, angiosarcoma) or progressive vascular tumors that have not responded to standard treatment.
Immunomodulatory and antiangiogenic drugs (IMiDs): Thalidomide and lenalidomide. Preferred for refractory discoid lupus erythematosus (DLE), erythema nodosum leprosum (ENL) in leprosy, and Kaposi sarcoma.
Topical and intralesional antiangiogenic modulators:
- Intralesional bevacizumab: Blocks the new vessels that feed hypertrophic scars, keloids and small hemangiomas.
- Topical beta-blocker (timolol 0.5%): Blocks beta-adrenergic receptors on endothelial cells and lowers expression of VEGF and HIF-1 alpha, causing vasoconstriction and regression of superficial infantile hemangiomas.

Comparing Antiangiogenic Drugs: Pharmacology and Indications

Active ingredient (generic)	Drug class	Main dermatologic indications
Bevacizumab	Monoclonal antibody	Recurrent keloids, Kaposi sarcoma, angiosarcoma
Thalidomide	Immunomodulator	Discoid lupus erythematosus, ENL, Kaposi sarcoma
Timolol (0.5% solution)	Non-selective beta-blocker	Superficial infantile hemangioma
Sunitinib	Multi-target TKI	Cutaneous angiosarcoma, metastatic melanoma

Managing Toxicity, Safety Warnings and Skin Side Effects

High blood pressure and proteinuria: Losing the effect of VEGF reduces nitric oxide (NO) and prostacyclin production by endothelial cells throughout the body, causing vasoconstriction and higher peripheral resistance. Patients on systemic bevacizumab or TKIs need regular blood pressure checks and urinalysis for protein.
Impaired wound healing and bleeding: VEGF is needed to form granulation tissue as wounds heal. Systemic antiangiogenic therapy must be stopped for at least 28 days before and after major dermatologic surgery to avoid wound breakdown or prolonged bleeding.
Hand-foot skin reaction (HFSR): A typical complication of antiangiogenic TKIs (sunitinib, sorafenib). It causes painful red bands, thick calluses or blisters on the pressure points of the palms and soles.
Teratogenicity of thalidomide: Thalidomide causes very severe birth defects (phocomelia, or "flipper limbs"). A strict risk-management program is mandatory, with monthly pregnancy tests and two simultaneous methods of contraception for both men and women throughout treatment.

Our Treatment Process at Haute-Derma

Assessing the Lesion's Blood Vessels

We use dermoscopy and high-frequency skin Doppler ultrasound (18–22 MHz) to assess the density, caliber and blood flow of the abnormal vessels within the lesion (keloid, hemangioma, psoriatic plaque).
We review the patient's cardiovascular history, any history of high blood pressure or clotting disorders, and kidney function.

Planning Local or Systemic Treatment

Intralesional bevacizumab for keloids and hypertrophic scars: Bevacizumab is diluted to 2.5 mg/mL (or combined with triamcinolone acetonide 10 mg/mL) and injected directly into the center of the scar at 0.2–0.5 mL per cm² of lesion. Sessions are repeated every 3–4 weeks.
Timolol 0.5% solution for infantile hemangiomas: Apply 1–2 drops of timolol 0.5% to the surface of a superficial hemangioma and spread gently, twice a day. Treatment continues for 3–6 months.

Regular Follow-Up and Toxicity Monitoring

Blood pressure and urine checks every 2–4 weeks for patients on systemic therapy.
After each course we assess how much the scar has softened, how much the vascular redness (scar color) has faded, and any change in tumor size.
Patients on thalidomide are monitored for numbness or tingling in the hands and feet to catch peripheral neuropathy early.

Frequently Asked Questions (FAQs)

+What are the advantages of intralesional bevacizumab over corticosteroid injection alone for keloids?

Corticosteroid injection alone (triamcinolone) can flatten a scar, but it often causes local side effects such as spidery telangiectasias, skin atrophy with a dent, and loss of pigment. Bevacizumab, whether combined with a steroid or used on its own, works by neutralizing VEGF and cutting off the scar's blood supply. This reduces perfusion and the oxygen available to fibroblasts, so collagen production falls without causing atrophy or secondary telangiectasia.

+Is topical timolol 0.5% safe for treating hemangiomas in newborns?

Topical timolol is very safe for small, superficial hemangiomas in children because very little of the drug reaches the bloodstream. Care is still needed: it should not be applied to scratched or broadly ulcerated skin or to open mucosa, where systemic absorption could slow the heart rate or cause bronchospasm. At Haute-Derma, our doctors check the child's baseline heart rate before prescribing it and show parents how to monitor the child closely during the first few days.

+How is hand-foot skin reaction (HFSR) from antiangiogenic TKIs managed at Haute-Derma?

Unlike the hand-foot syndrome seen with conventional chemotherapy, HFSR from antiangiogenic TKIs mainly affects pressure and weight-bearing points. To manage it, we advise patients to apply moisturizers containing 10–20% urea or 2–5% salicylic acid to soften the thickened skin, to wear soft, roomy, well-cushioned footwear, and to avoid hot water and heavy friction. For painful grade 2 or 3 HFSR, the doctor may consider temporarily lowering the TKI dose.