Switching from Cabenuva to Biktarvy in a Rilpivirine-Allergic Patient
Yes, switching to Biktarvy is safe and appropriate for a patient with rilpivirine allergy currently on Cabenuva, as Biktarvy contains no rilpivirine and represents a recommended first-line regimen with a high barrier to resistance. 1
Immediate Safety Considerations
The critical issue here is that the patient should not be continuing Cabenuva if they have a documented rilpivirine allergy, as Cabenuva contains rilpivirine (900 mg per injection). 2 This represents an urgent need to switch therapy regardless of Sunlenca availability.
Why Biktarvy is the Appropriate Choice
Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) is a recommended initial and switch regimen that contains no rilpivirine or related NNRTIs, eliminating cross-reactivity concerns. 3, 1
Key advantages for this switch:
- High barrier to resistance with bictegravir (integrase inhibitor) 3
- Single-tablet once-daily regimen taken with or without food 1
- No pharmacologic boosting required, reducing drug interaction potential 3
- Extensive data supporting switches from suppressive regimens 3, 4
Critical Switching Protocol from Long-Acting Injectable
Due to cabotegravir's prolonged half-life, you must initiate Biktarvy at least 1 month before the next scheduled Cabenuva injection would be due to prevent functional monotherapy and resistance development. 5
Specific timing requirements:
- Start Biktarvy immediately given the allergy concern 5
- Do not administer any further Cabenuva injections 5
- The rilpivirine component has a long elimination phase, requiring overlap with fully suppressive therapy 5
Pre-Switch Assessment Requirements
Before switching, verify:
- Review all prior resistance testing results to ensure no NRTI or integrase resistance 3
- Test for hepatitis B coinfection - if positive, Biktarvy is appropriate as it contains tenofovir alafenamide with anti-HBV activity 3, 1
- Assess renal function (serum creatinine, estimated creatinine clearance) - Biktarvy requires CrCl ≥30 mL/min 1
- Check for potential drug interactions, particularly with medications affecting tenofovir alafenamide 5, 1
Post-Switch Monitoring Protocol
Check HIV viral load at 1 month after initiating Biktarvy, then every 3 months for the first year. 3, 5 This is critical given the switch from long-acting therapy and the allergy concern.
Additional monitoring:
- Assess serum creatinine, urine glucose, and urine protein as clinically appropriate during Biktarvy treatment 1
- If chronic kidney disease is present, also monitor serum phosphorus 1
- Provide adherence support, as switching from monthly injections to daily oral therapy may present adherence challenges 5
Common Pitfalls to Avoid
- Never continue Cabenuva in a patient with documented rilpivirine allergy - this is contraindicated 6
- Never discontinue long-acting cabotegravir without immediately starting effective alternative therapy due to prolonged elimination and resistance risk 5
- Do not switch to Biktarvy if there is documented NRTI or integrase resistance without expert consultation 3
- For hepatitis B coinfection, never switch to a regimen lacking anti-HBV activity - Biktarvy is appropriate as it contains tenofovir alafenamide 3, 1
Sunlenca Consideration
While awaiting Sunlenca approval is mentioned, this should not delay the switch given the documented allergy. Biktarvy represents definitive long-term therapy, not merely a bridge regimen. 3, 1