What is the role of Xiaflex (collagenase clostridium histolyticum) in treating Peyronie's disease?

Xiaflex for Peyronie's Disease

Xiaflex (collagenase clostridium histolyticum) should be offered to patients with stable Peyronie's disease who have penile curvature between 30° and 90°, a palpable plaque, and intact erectile function, as it is the only FDA-approved non-surgical treatment for this condition. 1, 2

Patient Selection Criteria

The AUA guidelines provide a Moderate Recommendation (Evidence Strength Grade B) for intralesional collagenase clostridium histolyticum with modeling, but only for appropriately selected patients 1:

• Curvature requirements: Between 30° and 90° 1, 2
• Erectile function: Must have intact erectile function without use of medications (though some protocols allow for pharmacotherapy) 1
• Disease stability: Symptoms unchanged for at least 3 months, minimal or no pain, established plaque 2
• Palpable plaque: Confirmed on physical examination 2, 3
• Age: Must be ≥18 years 3

Treatment Protocol

The FDA-approved protocol involves 2, 3:

• Dosing: 0.58 mg (10,000 U) per injection into the Peyronie's plaque at the point of maximal curvature 3, 4
• Cycle structure: Two injections per cycle, administered 24-72 hours apart 5, 4
• Total treatment: Up to 4 cycles (8 total injections) over 24 weeks 2, 3
• Cycle spacing: 6 weeks between cycles 3, 4
• Modeling: Both clinician-administered (24-72 hours after second injection) and patient-performed daily modeling exercises are essential components 1, 2, 3

Expected Outcomes

Realistic expectations must be set with patients 2, 3:

• Mean curvature reduction: Approximately 17° with CCH versus 9.3° with placebo at one-year follow-up 2, 3
• Response rates: 66.7-84.6% of patients achieve composite response (≥20% decrease in curvature plus improvement in bother score) 5
• Calcified plaques: CCH remains effective even in calcified plaques, with similar improvement of 15-17.5° regardless of calcification type 6

Safety Profile and Adverse Events

Patients must be counseled about potential complications 2, 3:

• Common adverse events (84.2% of patients experience at least one): Penile ecchymosis, swelling, pain, contusion, hemorrhage 2, 3, 5
• Most events: Mild to moderate and resolve without intervention 2, 3
• Rare but serious complications: Corporal rupture, lateral herniation of tunica albuginea 2, 7
• Herniation warning signs: Soft, painless mass with erection should raise suspicion 7

Critical Limitations and Pitfalls

Xiaflex is NOT indicated for pain management 2:

• The AUA explicitly states that "intralesional collagenase is a therapy for curvature; it does not treat pain or erectile dysfunction" 2
• For patients with active disease and penile pain, oral NSAIDs are the recommended first-line treatment 2
• Using CCH specifically for pain relief represents off-label use not supported by guidelines and could delay appropriate pain management 2

Treatment discontinuation criteria 3:

• If curvature decreases to <15° after treatment cycles, subsequent cycles should not be administered 3
• Safety of more than one treatment course has not been established 3
• Some patients may still have residual curvature requiring additional interventions 3

Provider Requirements

Treatment should only be administered by clinicians experienced in urological disease treatment 2, 3. The modest average improvement (17° reduction) means patients may still require surgical intervention if functional impairment persists 2, 3.

Alternative Considerations

For patients who do not meet criteria for CCH 2:

• Active disease with pain: Oral NSAIDs as first-line 2
• Curvature <30° or >90°: Consider observation, penile traction therapy, or surgical options 2
• Erectile dysfunction present: May require penile prosthesis surgery instead 1