Is continued treatment with Remicade (Infliximab) IV 500 MG every 8 weeks medically necessary for a patient with severe, refractory Hidradenitis Suppurativa (HS)?

Continued Infliximab Treatment for Hidradenitis Suppurativa: Medical Necessity Assessment

Yes, continued treatment with Remicade (infliximab) 500 mg IV every 8 weeks is medically necessary and appropriate for this patient with severe, refractory hidradenitis suppurativa who has demonstrated sustained disease control and good tolerability.

Guideline-Based Recommendation

The British Association of Dermatologists explicitly recommends infliximab 5 mg/kg every 8 weeks for moderate-to-severe HS that is unresponsive to adalimumab therapy (Recommendation 14, strength ↑). 1 This patient meets these criteria precisely:

• Failed adalimumab and its biosimilar prior to infliximab initiation
• Has severe, multi-site disease (bilateral axillae, bilateral inguinal folds, bilateral abdomen, right periareolar breast)
• Long disease duration (29 years, since age 18)
• Multiple prior surgical interventions for HS cysts/tracts
• Currently achieving disease control on infliximab 1

Dosing Appropriateness

Current Regimen Analysis

The patient receives 500 mg every 8 weeks. While the British Association of Dermatologists specifies 5 mg/kg every 8 weeks as the standard dose 1, this patient's actual weight-based dosing needs verification:

• At 47 kg body weight: 500 mg = 10.6 mg/kg (higher than standard)
• At 100 kg body weight: 500 mg = 5 mg/kg (standard dose)

The American Academy of Dermatology supports flexible dosing, noting that 78% of patients achieved at least 50% improvement in HS scores with infliximab, and post-hoc analyses showed 13 of 15 patients achieved ≥25% improvement at week 8. 2

Evidence for Dosing Optimization

Recent evidence suggests that 10 mg/kg every 6-8 weeks may be optimal for most HS patients, with 64% requiring dose escalation at 1 year. 3 The retrospective cohort of 52 patients found that 67% achieved stable dosing, most commonly at 10 mg/kg every 6 or 8 weeks. 3

For this patient on maintenance therapy since December 2024 (approximately 9 months), the every-8-week interval aligns with both guideline recommendations and real-world dosing patterns. 1, 3

Evidence of Treatment Response

The patient demonstrates clear continuation criteria per Aetna's policy and clinical evidence:

• Disease remains "well controlled" on current regimen (documented 9/26/2025)
• Good tolerability with no adverse reactions during infusions on 7/24/2025 and 9/19/2025
• No new abscess formation, inflammatory nodules, or draining fistulas reported
• Patient explicitly wishes to continue therapy 1

Prospective studies demonstrate that infliximab provides sustained efficacy with good tolerance over 1 year, with significant improvements in quality of life (mean DLQI improving from 20/30 to 6/30, P<0.001) and reduction in disease severity without therapeutic escape. 4

Safety Considerations and Monitoring Gap

Critical Caveat: Missing TB Screening

A significant documentation gap exists: no tuberculosis screening results are provided. The Aetna policy explicitly requires documented negative TB testing (TST or IGRA) within 12 months of initiating therapy for biologic-naïve patients. 2

Before approving continuation, confirm:

• TB screening was completed prior to December 2024 initiation
• If positive screening occurred, chest X-ray ruled out active disease
• Latent TB treatment was completed if indicated
• Annual TB testing is being performed for ongoing therapy 2

Infusion Reaction Monitoring

Infusion reactions occur in up to 20% of patients treated with infliximab and can rarely result in anaphylactic shock. 1 This patient has tolerated two documented infusions without adverse reactions, which is reassuring. 1

Standard of Care Determination

This treatment plan represents standard of care based on:

1. Guideline-concordant therapy: British Association of Dermatologists Recommendation 14 (↑) specifically endorses infliximab 5 mg/kg every 8 weeks for adalimumab-refractory HS 1

2. Appropriate treatment sequencing: Patient failed oral tetracyclines (implied by progression to biologics), failed adalimumab and biosimilar, meeting criteria for second-line biologic therapy 1

3. Demonstrated clinical efficacy: Randomized controlled trial data show statistically significant improvements in HS Severity Index (≥50% decrease), Dermatology Life Quality Index, pain scores, and inflammatory markers (ESR, CRP) compared to placebo 5

4. Sustained response without therapeutic escape: Prospective data support continued efficacy through 1 year of treatment with satisfactory tolerance 4

Treatment Necessity Justification

Medical necessity is established through:

• Disease severity: Multi-site involvement across 7 anatomic locations with 29-year history
• Refractory nature: Failed multiple conventional therapies and first-line biologic (adalimumab)
• Surgical history: Multiple prior procedures indicate severe, recurrent disease
• Current disease control: Documented stability on infliximab preventing disease progression, abscess formation, and fistula development
• Quality of life: HS significantly impairs QOL (mean baseline DLQI 20/30 in studies); maintaining control prevents this morbidity 4

Discontinuing effective therapy would likely result in disease flare, as studies show variable time to relapse (though data suggest maintaining treatment reduces risk of treatment resistance, extrapolated from Crohn's disease experience). 1

Recommendation Summary

Approve continuation of infliximab 500 mg IV every 8 weeks contingent on:

1. Verification of TB screening completion (if not documented, obtain immediately)
2. Confirmation of actual weight-based dosing (ensure 500 mg represents appropriate mg/kg dose)
3. Ongoing monitoring for infusion reactions, infections, and disease activity
4. Dermatology specialist oversight (already in place with PA Ciallella)

The treatment is medically necessary, represents standard of care per British Association of Dermatologists guidelines, and is supported by Level 1 evidence from randomized controlled trials demonstrating efficacy and safety. 1, 5