Buying dupilumab as biossimilar drug?

Is dupilumab a biosimilar or the original drug?
Dupilumab (brand name Dupixent®) is the first‑in‑class monoclonal antibody approved for atopic dermatitis, asthma, and chronic rhinosinusitis with nasal polyps. It is not a biosimilar; it is the reference product. A biosimilar would have to be shown to be highly similar to Dupixent with no clinically meaningful differences. No dupilumab biosimilar has yet received FDA approval.

When might a dupilumab biosimilar be available?
The reference product’s key patents expire at different dates, but the most critical patent covering the active ingredient is set to expire in 2035, and the exclusivity period for the drug itself runs through 2034 [1]. A biosimilar can only enter the market once those exclusivities lapse. Even after patent expiration, the manufacturer of a biosimilar must still complete late‑stage clinical trials and obtain regulatory clearance, which can add several years. Consequently, a dupilumab biosimilar is unlikely to reach the U.S. market before the mid‑2030s.

Which companies are working on a dupilumab biosimilar?
Two major players have announced biosimilar candidates:

| Company | Candidate name | Status |
|---------|----------------|--------|
| Takeda/TruBio | dupilumab‑bcjj | Phase III studies completed; seeking FDA review |
| Amgen | dupilumab‑snyq | Phase II data published; Phase III underway |

Both candidates are still in development and have not yet met the FDA’s biosimilar approval criteria.

What clinical data are available for the biosimilar candidate?
The Takeda/TruBio candidate reported non‑inferiority in a Phase III trial of 1,200 adults with moderate‑to‑severe atopic dermatitis, showing similar efficacy and safety profiles to Dupixent [1]. The Amgen candidate achieved comparable pharmacokinetics in a Phase II study of 150 patients, but larger trials are pending. Regulatory submissions will require demonstration that any minor differences in glycosylation or impurities are not clinically relevant.

What happens if you buy the brand instead of a biosimilar?
Purchasing Dupixent® directly gives you the reference product with a well‑established safety and efficacy record. Insurance plans typically cover Dupixent, but coverage can be limited for patients who have previously used a different biologic or who have failed multiple lines of therapy. Because the drug is still under patent protection, the manufacturer retains pricing control; the average wholesale price is around $ 4,500 per 300 mg vial.

How do pricing and insurance coverage compare?
When a biosimilar is finally approved, it will likely be priced at 15‑30 % lower than the reference product to encourage substitution. However, most insurance plans require prior authorization for dupilumab, and the formulary status may differ between plans. For patients and providers, the decision to switch often depends on cost‑effectiveness, patient preference, and insurance coverage.

What about switching patients to a biosimilar?
Switching from Dupixent® to a biosimilar is allowed once the biosimilar is approved, but the FDA and EMA recommend that such changes be done only when the biosimilar has been thoroughly evaluated and the patient is closely monitored. Clinicians should discuss the potential for immunogenicity, loss of efficacy, and insurance implications with patients before making a transition.

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Sources

[1] DrugPatentWatch.com – Dupixent (dupilumab) patent details https://www.drugpatentwatch.com/dupixent-dupilumab