PHOTOFRIN (PORFIMER SODIUM)
THE MOST WIDELY APPROVED PDT PHOTOSENSITISER

Photofrin (generic name: porfimer sodium) is a hematoporphyrin derivative — derived from haem, the iron-containing component of haemoglobin. It is a mixture of porphyrin monomers, dimers, and oligomers that collectively form the active photosensitising compound. Developed in the 1970s and approved by the FDA in 1995, it remains the most widely approved PDT photosensitiser in the world — not because it is the best in every parameter, but because it was first and has accumulated the most regulatory approvals and clinical experience.

“Photofrin is the workhorse of clinical PDT. Newer photosensitisers may outperform it in some parameters — but Photofrin's three decades of clinical use, regulatory approvals across multiple countries, and well-characterised safety profile make it the reference standard.”

• First-Generation Classification

  Photofrin is classified as a "first-generation" photosensitiser — meaning it was among the earliest compounds developed for clinical PDT. First-generation agents are characterised by their broad absorption spectrum, relatively slow clearance from normal tissue (producing prolonged photosensitivity), and reliable activation at 630 nm. Newer "second-generation" agents like temoporfin and verteporfin are more chemically pure and clear faster, but have more limited regulatory approvals.

• FDA-Approved Indications

  Photofrin holds FDA approval for three distinct oncology indications: (1) Oesophageal cancer — both obstructing tumours and superficial lesions; (2) Endobronchial non-small-cell lung cancer — palliation of obstruction and curative intent for early-stage microinvasive disease; (3) Barrett's oesophagus with high-grade dysplasia — ablation of pre-malignant mucosal changes to prevent progression to invasive cancer.

Photofrin PDT is a two-phase treatment — drug phase followed by light phase — with a critical 40–50 hour waiting interval between them.

1. 1

   Phase 1: Intravenous Drug Administration

   Photofrin is injected intravenously at a dose of 2 mg/kg body weight over 3–5 minutes. The injection is typically done as a day procedure — patient goes home the same day. Photosensitivity begins immediately; strict light avoidance must start from the moment of injection. The drug is clear; patients feel nothing during injection.

2. 2

   Waiting Period: 40–50 Hours for Selective Accumulation

   The waiting period allows the photosensitiser to accumulate selectively in tumour cells while clearing from surrounding normal tissue. This differential retention is the basis of PDT selectivity. During this period the patient rests at home or in hospital, practising full light avoidance. The wait cannot be shortened — activating the drug before 40 hours risks inadequate tumour selectivity and increased normal tissue damage.

3. 3

   Phase 2: Endoscopic Light Delivery at 630 nm

   Under conscious sedation, a flexible endoscope is passed into the oesophagus (or bronchoscope into the airway). A thin optical fibre is passed through the endoscope and positioned at or within the tumour. Red laser light at 630 nm is delivered at 200–400 J/cm² for 8–16 minutes. The tumour tissue illuminated by the fibre is activated and begins to undergo cell death.

4. 4

   Debridement Endoscopy (48 Hours After Light)

   A repeat endoscopy 48 hours after light delivery removes necrotic tissue (tumour slough) that has formed in the treated area. This step is critical for oesophageal PDT to prevent luminal obstruction from sloughed tissue. Patients typically experience relief of dysphagia at this point.

5. 5

   Repeat Treatment If Required

   If residual tumour is identified on endoscopic assessment, the light delivery phase can be repeated 96–120 hours after the first light (still within the drug's retention window, typically 4–5 days after injection). If further treatment is needed beyond this window, a new drug injection is required.

Technical characteristics of Photofrin relevant to clinical use.

Photofrin has a favourable overall safety profile compared to chemotherapy — no nausea, no hair loss, no myelosuppression. The dominant and most practically impactful side effect is prolonged photosensitivity.

• Prolonged Photosensitivity (4–6 Weeks) — The Critical Side Effect

  Photofrin remains in skin tissue for weeks after injection. Any sun exposure or bright indoor light during this period activates the drug in skin, causing phototoxic reactions — erythema (redness), oedema (swelling), blistering, and in severe cases, tissue necrosis. This is not an allergy; it is a pharmacological effect. Strict light avoidance is mandatory. See the dedicated PDT Photosensitivity Protection Guide for full management.

• Local Procedure-Related Effects

  Oesophageal PDT: dysphagia (difficulty swallowing), chest pain, and odynophagia (painful swallowing) for 1–2 weeks post-procedure from oesophageal inflammation. Oesophageal stricture develops in 5–20% of patients (requiring dilation) — related to circumferential treatment. Endobronchial PDT: cough, haemoptysis, and temporary airway inflammation.

• Systemic Effects (Uncommon)

  Low-grade fever for 2–5 days from tumour necrosis (similar to post-ablation syndrome). Mild constipation or nausea from dehydration or opioid pain relief. Reversible transaminase elevation in some patients.

How Photofrin compares to second-generation photosensitisers clinically available.

Related PDT topics and resources.

Frequently Asked Questions

Common questions about Photofrin.