Kinase Chemistry – Just a year and a half behind the times.

BAY 73-4506

Posted by kinasepro on May 20, 2009

So Bayer is in Ph2 with fluoro-sorafenib aka DAST, BAY-734506… Only this time they’re in without Onyx and I gather Onyx is none too happy about this.

BAY-734506The distinct compound is claimed in WO/2005/009961 and the I believe the original Sorafenib app is: WO/2000/042012.  What strikes the chemist inventor about a structure like this isn’t usually about who owns it, but if it can really be considered a new invention? The claim structure in the 2000 Sorafenib application can be schematized:

sorafenib-claimsSo for the purpose of this discussion the only meaningful definition is the ring designated as “L” and whether or not they claim the fluoride:

L-definedAnyhow while this structure and their priority date may be vulnerable to obviousness, all of these applications are assigned to Bayer, and not Onyx, so that disagreement will more likely be resolved based on the wording of the Onyx / Bayer contract.  The Onyx press release suggests this very structure was discovered during the collaboration…  We’ll see.  Given the timing I bet someone saw the structure here on Kinasepro and told Onyx, heh.

5 Responses to “BAY 73-4506”

  1. anonymous1 said

    So, this molecule was known since 1998… If it is indeed more potent/safe, then why was it not put forward instead of sorafenib ? Or Bayer wanted to milk out the patent time of a lesser drug and after it goes generic, “discover” a better drug ?? For me, such behaviour with respect to cancer sufferers is worse than all bankers antics !

    • kinasepro said

      There are quite a few reasons for this kind of thing…

      It’s conceivable that the molecule was thought to be inferior at the time, only later to be re-discovered. It also could have come along some time after sorafenib was already ‘in development’. Once a molecule is chosen for IND enabling studies switching compounds, even if its just a single Fluoro atom, can lead to logistical quagmire of missed timelines.

      Also recall that at the time it was very much a race to market. If sorafenib was delayed 6 months its quite likely that sunitinib would likely have garnered a sizeable lead in market share which would have made competition much more difficult both monetarily and in competing for patients in the important trials…

      • milkshake said

        In this respect it its interesting that Pfizer shelved the follow-up to Sunitinib, SU14813 because it was slightly less potent and shorter-acting (unlike Suten has to be dosed higher and twice a day) but SU14813 should have much better safety profile – no QTc prolongation, no active metabolites, no organ accumulation that forces Sutent “holiday” interruptions in the regiment, and a linear dose-response curve.

  2. petros said

    A useful patent analogy to this is that of Lilly’s flumezapine and olanzapine (the des-fluoro analog). The latter was the subject of later patents, and hugely succesful, Lilly succesfully argued its case on the validity of the patents covering the latter in a case ruled on by the Court of Appeals for the Federal Circuit in January 2007

  3. petros said

    INN is regorafenib, which confirms the structure

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