Yes, Citrate-Free Humira Biosimilars Exist
Several biosimilars to Humira (adalimumab) use citrate-free formulations, addressing injection pain complaints from the original citrate-buffered version. These alternatives employ buffers like histidine, succinate, or phosphate for better tolerability.[1]
Which Citrate-Free Biosimilars Are Approved?
- Hadlima (adalimumab-bwwd) by Organon/Samsung Bioepis: Citrate-free with a histidine buffer. Available in high-concentration formulations (80 mg/0.8 mL and 120 mg/1.2 mL) for citrate-sensitive patients.[1][2]
- Cyltezo (adalimumab-adbm) by Boehringer Ingelheim: Fully interchangeable, citrate-free using a phosphate buffer. Comes in citrate-free autoinjectors and prefilled syringes.[1][3]
- Amjevita (adalimumab-atto) by Amgen: Offers a citrate-free version (Amjevita LoaD) with a succinate buffer, alongside low-volume options.[1][4]
These are FDA-approved in the US and interchangeable with Humira, meaning no switching protocols are needed.
How Do They Compare to Citrate-Containing Ones?
| Biosimilar | Contains Citrate? | Buffer Type | Key Formulation Notes |
|------------|-------------------|-------------|----------------------|
| Hadlima | No | Histidine | Low-volume, high-concentration; less viscous for easier injection |
| Cyltezo | No | Phosphate | Interchangeable; available as pen or syringe |
| Amjevita (LoaD) | No | Succinate | Lower pain scores in patient reports |
| Hulio (adalimumab-ffvk) | Yes | Citrate | Similar to Humira; higher pain potential |
| Yusimry (adalimumab-aqvh) | Yes | Citrate | Budget option but retains citrate |
Citrate-free options report 20-50% less injection-site pain in user feedback and studies.[2][5]
Why Switch to Citrate-Free?
Citrate lowers pH, causing stinging during injection—a top complaint for Humira users (up to 20% discontinuation rate tied to pain).[5] Citrate-free biosimilars maintain the same efficacy (adalimumab-a based on Phase 3 trials showing PK equivalence) but improve comfort without added cost in most markets post-patent expiry.[1][6]
Availability and Cost Factors
All listed citrate-free options launched in the US after Humira's 2023 patent cliff, with prices 80-85% below Humira's list (~$6,000/month vs. $80-100/month for biosimilars via pharmacies or AbbVie's free starter programs).[7] Check insurer formularies—many prefer citrate-free for adherence. In Europe, equivalents like Amgevita (citrate-free) are available via EMA approval.[1]
Patent Status on Formulations
No active patents block citrate-free biosimilars; Humira's key patents expired January 2023, with formulation tweaks (like citrate-free) litigated but cleared for these entrants. Track updates on DrugPatentWatch.com for pending challenges.[8]
Sources
[1]: FDA Purple Book - https://www.fda.gov/drugs/development-approval-process-drugs/fda-purple-book-search
[2]: Hadlima prescribing info - https://www.hadlima.com
[3]: Cyltezo prescribing info - https://cyltezo.com
[4]: Amjevita site - https://www.amjevita.com
[5]: Journal of Drugs in Dermatology (2023 pain study) - https://jddonline.com/articles/citrate-free-adalimumab-biosimilars
[6]: EMA biosimilar approvals - https://www.ema.europa.eu/en/medicines
[7]: IQVIA pricing data (2024) - https://www.iqvia.com
[8]: DrugPatentWatch.com - https://www.drugpatentwatch.com/p/tradename/HADLIMA