porfimer

SYNONYM(S):   DHE; dihematoporphyrin ether; Porfimer sodium

COMMON TRADE NAME(S):   Photofrin® (Concordia Laboratories)

• Superficial papillary bladder cancer, recurrent after standard treatment
• Esophageal cancer, palliation of dysphagia and obstruction
• High grade dysplasia associated with Barrett’s esophagus when surgery refused
• Endobronchial cancer: obstructive lesions or superficial micro invasive tumours where surgery or radiation not indicated

Emetogenic Potential:  

Extravasation Potential:   Irritant

* "Incidence" may refer to an absolute value or the higher value from a reported range.
"Rare" may refer to events with < 1% incidence, reported in post-marketing, phase 1 studies,
isolated data or anecdotal reports.
Dose-limiting side effects are underlined.

** I = immediate (onset in hours to days)     E = early (days to weeks)
D = delayed (weeks to months)      L = late (months to years)

The most common side effects for porfimer include photosensitivity, urinary frequency, hematuria, GI stenosis, nausea, vomiting, dysuria, fever, dyspnea, pleural effusion and anemia.

GI symptoms are mainly observed with treatment of GI lesions, respiratory symptoms with treatment of lung or esophageal lesions, and genitourinary symptoms with treatment of bladder lesions.

Photosensitivity is the most common adverse effect and occurs in essentially all patients. Following photodynamic therapy with porfimer, steps must be taken to protect the eyes and skin from exposure to direct sunlight (outside or through window glass) or brightly focused indoor light (e.g., desk lamps, bright reading lamps, medical or dental examination lights, operating room lamps, etc.) for a 30 day period. Exposure for even a few minutes can result in severe sunburn causing redness and blistering of the exposed skin. The use of sunscreens does not provide adequate protection from sunlight and strict sun avoidance (i.e., hat, gloves, sunglasses, long-sleeved, full-length clothing) is advised. However, the patient should not remain in a completely darkened room during this period of time, since exposure to low light levels such as ambient room light may be important for photo bleaching or photo inactivating the residual drug in the skin. An opaque sun block such as zinc oxide or titanium dioxide should be applied to exposed skin when outdoors. Transparent sunscreens such as PABA (para-aminobenzoic acid) are inadequate for protection from sunburn with porfimer, since photoactivation is caused by visible light.

After 30 days, the patient may expose a small area of skin (e.g., finger, dorsum of hand) to the sun for 10 minutes to test for residual photosensitivity. If significant blistering or redness occurs, the patient should continue precautions against sun and bright light exposure for another 2 weeks before retesting the effects of limited sun exposure.

Other adverse effects are primarily local and in the area being treated. Esophageal strictures are common after treatment for high grade dysplasia associated with Barrett's esophagus, but are usually managed by dilatation.

Photodynamic therapy (PDT) of lung cancer: For large, obstructive lesions where the patient is unable to cough up the tumour debris, a clean-up bronchoscopy is necessary 2-3 days after laser light delivery to clear away the tumour debris and open up the trachea or the bronchus to full extent. Life-threatening hemoptysis and respiratory failure may occur.

• Patients with porphyria or with known allergies to porphyrins
• Use is not recommended in patients with tumours eroding, or with the potential to erode into vessels, the trachea or bronchus as they are at high risk of developing fistulas or bleeding, nor in patients with varices or esophageal ulcers > 1 cm. 
• Patients with prior total bladder irradiation, or with a functional bladder capacity less than 200 mL, should not be treated with photodynamic therapy to the bladder as there is the possibility of irreversible bladder contracture from increased fibrosis. Patients with coexisting bladder tumours of stage greater than T1, who have invasive cancer, must not receive PDT.

• Patients with esophageal varices or endobronchial tumours should be treated with extreme caution.
• Use of PDT has not been studied in patients with significant cardio-pulmonary symptoms.
• PDT is not suitable for emergency treatment of patients with severe acute respiratory distress caused by an obstructing endobronchial lesion because 40-50 hours are required between injection with porfimer sodium and laser light treatment. The inflammatory response induced may lead to increased obstruction and symptoms. Sufficient time to recover (2-4 weeks) should be allowed between any radiation treatment and porfimer administration.
• Patients must avoid exposure of eyes and skin to direct sunlight or bright focused indoor light for 30-90 days after dosing and should wear protective clothing and dark sunglasses; sunscreens are ineffective. Ambient indoor light exposure is desirable.

• Excretion into breast milk: Probable
  

  Breastfeeding is not recommended.

• Fertility effects: Unknown
  

Grade toxicity using the current NCI-CTCAE (Common Terminology Criteria for Adverse Events) version

New Drug Funding Program (NDFP Website )

• Porfimer Sodium - Photodynamic Therapy

October 2017 updated supplementary public funding link, reformatted special precautions section