What is the FDA “Purple Book” exclusivity expiration date for the daratumumab reference product?
The FDA Purple Book lists biologic drug exclusivity periods for FDA-approved products, including the reference product for daratumumab. However, the exclusivity expiration date depends on the specific daratumumab reference product name (and formulation/approval pathway) shown on the Purple Book.
Which daratumumab “reference product” should you look up?
To get the correct exclusivity expiration date, confirm the exact reference product entry in the Purple Book, typically by matching:
- the brand name (and/or label name),
- the manufacturer,
- and the relevant dosage form/strength (if the Purple Book lists multiple entries).
Different daratumumab reference product entries (or later supplemental approvals) can have different exclusivity timelines, so using the wrong reference product name can produce an incorrect expiration date.
Where exactly do you find the expiration date on the Purple Book?
On the Purple Book page for the specific daratumumab reference product entry, FDA shows exclusivity information that includes the exclusivity type and an expiration date. Use the entry’s “Exclusivity” section to read the expiration date for that specific reference product.
How can the expiration date differ from when biosimilars actually launch?
Even after an exclusivity period ends, biosimilar availability can still be affected by:
- FDA approval timing for the biosimilar,
- patent and litigation status (which can delay launches even if exclusivity ends),
- product supply and commercialization plans.
So the Purple Book exclusivity expiration date tells you when exclusivity protection ends for that reference product, not necessarily the first day a biosimilar is sold.
If you share the exact daratumumab reference product name, can you pinpoint the date?
Yes. If you paste the exact Purple Book entry name you’re using for daratumumab (brand/manufacturer as shown on the Purple Book page), I can help you identify the corresponding exclusivity expiration date for that exact reference product.
Sources
- [1] FDA Purple Book (Drugs/biologics exclusivity): https://purplebooksearch.fda.gov/