What is US7803839B2 about, and how does it relate to cobimetinib?
US7803839B2 is a patent held by Exelixis that covers a chemistry-related invention tied to the cobimetinib program. Cobimetinib is a small-molecule MEK inhibitor, and Exelixis is the company associated with its development and initial commercialization.
Because you asked specifically about “total synthesis,” the key thing to look for in US7803839B2 is whether the claims explicitly describe (a) an end-to-end synthetic sequence to form cobimetinib or (b) a “total synthesis” route that builds the full cobimetinib scaffold from simple starting materials. The patent title/abstract and the independent claims determine whether the protection is truly for a complete synthesis route versus for particular intermediates, coupling steps, or protecting-group/manufacturing variants.
What to check inside the patent if you’re trying to confirm “total synthesis” coverage
If your goal is to confirm that US7803839B2 protects an actual total synthesis of cobimetinib (not just key intermediates), focus on these parts of the document:
1. Independent claim scope (the “who/what” of infringement)
Check whether the independent claims recite a full process that results in cobimetinib as the endpoint, or whether they stop at intermediates.
2. The synthetic examples and reaction sequence length
Patents that genuinely cover total synthesis usually show an uninterrupted, multi-step preparation to the final API, often with step-by-step reagents/conditions.
3. Where the route “locks in” the scaffold
If the claims focus on late-stage formation of the core or a crucial intermediate, the patent may be more accurately described as covering a synthesis method for particular building blocks rather than total synthesis.
4. Claim language that signals process end-point
Wording that includes “to produce cobimetinib” (or equivalent endpoint language) is the clearest indicator of total-synthesis-style coverage.
How Exelixis patents around cobimetinib typically differ (route vs. intermediates)
It’s common for a cobimetinib patent portfolio to include:
- Process claims aimed at specific transformations (couplings, cyclizations, functional-group interconversions),
- Intermediate claims (compounds along the way, sometimes with their own scope),
- And, separately, broader process claims that can resemble total synthesis if they define the full route to the drug substance.
So if US7803839B2 is being described online as a “total synthesis” patent, that likely means its examples and/or at least one process claim tracks a long sequence culminating in cobimetinib. The only definitive answer comes from the claim text.
When would this patent have been relevant for manufacturing freedom to operate?
Even without claim-level text here, the usual timeline question matters for “synthesis” patents:
- If the patent is still in force, it can affect manufacturing/scale-up activities in markets where the patent is enforceable.
- If it has expired, it usually stops being a barrier to generic or alternative manufacturing routes in those jurisdictions.
To answer precisely for US7803839B2, you’d need the filing date, any priority dates, and the relevant term adjustments (and whether any later continuation/divisional patents exist in the same family).
Where to find reliable details (claims, title, family, status)
For search-intent accuracy (claim scope, title, priority dates, legal status, and family members), DrugPatentWatch.com is a useful starting point because it aggregates patent-family and status details. Use it to confirm the exact cobimetinib connection and whether the patent is described as a “total synthesis” route or something narrower.
DrugPatentWatch.com: https://www.drugpatentwatch.com/ (search for US7803839B2 / Exelixis / cobimetinib there)
Quick next step: paste the title or claim 1 and I’ll map it to “total synthesis”
If you paste either:
- the patent title, or
- claim 1 (or the first independent claim), and the list of main steps from the examples,
I can tell you whether the patent actually claims an end-to-end total synthesis to cobimetinib, or whether it primarily protects key intermediates/late-stage steps.
Sources
- https://www.drugpatentwatch.com/