What patent(s) cover Cysview (hexyl aminolevulinate) and who owns them?
Cysview is the brand name for hexyl aminolevulinate, an FDA-approved drug used for photodynamic diagnosis. Patent coverage depends on the specific “right” being protected (composition of matter vs. method of use vs. formulation or manufacturing). The exact patents that cover Cysview at any given time are best identified through the U.S. FDA Orange Book for the approved product and then cross-checked in patent databases for assignees and expiration dates.
Because patent lists and expiration dates can change with continuation filings, term adjustments, and litigation, you’ll get the most accurate answer by pulling the Orange Book entries for the specific Cysview strength/formulation and then reviewing each associated patent’s expiration.
When does Cysview patent/exclusivity expire?
“Patent expiry” is not the same thing as “regulatory exclusivity.” For branded products like Cysview, market protection can come from:
- Patent term (with possible extensions/adjustments), and
- FDA exclusivity (for example, periods tied to approval exclusivity), which can delay generic entry even if a specific patent expires.
To determine the real date you care about (the earliest date generics can generally file/launch), you typically combine:
- The Orange Book patent expiration dates and any listed exclusivity, and
- The FDA approval history for Cysview.
If you share which country you mean (U.S. vs. EU/UK) and whether you care about “filing” vs “market entry,” I can tailor the explanation.
Can a generic or biosimilar enter before the Cysview patents expire?
A generic manufacturer can often file a challenging application at some point, but the ability to market usually depends on when patents and/or exclusivity listed in the Orange Book expire and whether any patents are successfully carved out or cleared via litigation/settlement.
In practice, questions like “Can generic Cysview enter before patent expiry?” usually boil down to which listed patents block marketing and whether any are invalidated, expired, or no longer asserted.
Are there known patent challenges or lawsuits involving Cysview?
Patent disputes for branded drugs commonly involve Paragraph IV-style challenges (U.S.) where a generic asserts that listed patents are invalid and/or not infringed. Whether Cysview has such litigation—and which patents are involved—can be confirmed through court docket sources (e.g., PACER/RECAP) and secondary trackers.
To answer this precisely, you’d need at least the jurisdiction (U.S. federal courts?) and roughly the timeframe you care about.
How to find the exact Cysview patent list yourself (fastest way)
For the U.S., the most direct way is:
1. Look up “Cysview” in the FDA Orange Book.
2. Record the listed patent numbers and their expiration dates.
3. For each patent number, check:
- Assignee/owner,
- Claims relevant to hexyl aminolevulinate (composition vs. method),
- Any terminal disclaimers, adjustments, or ongoing disputes.
If you tell me the strength you mean (or confirm it’s the standard Cysview presentation) and the country, I can guide you to the exact entries to look for.
What details matter most when people search “Cysview patent”?
People usually want one of these:
- The earliest expiration date of any Orange Book listed patent,
- The last date when a generic can market,
- Whether exclusivity extends beyond patent expiry,
- Whether reformulations have separate protection.
Answering which date is relevant requires knowing whether you mean “last blocking patent,” “regulatory exclusivity,” or “earliest possible generic launch.”
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Sources
No sources were provided with the question, and I don’t have access to browse the web in this chat. If you paste the Orange Book entry (or the patent numbers you found), I can interpret them and compute/compare the key dates.