Replies to post #25512 on Biotech Values

[DewDiligence]

Favor requested…

I can’t currently post on Yahoo for some reason. Would someone be kind enough to copy the message below and post it on the NSTK ymb in reply to #49936? T.i.a. Dew

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>L or S and I had a brief discussion about the prospective size of a molecule required for an exenatide LAR formulation (actually related to the time release language I located in the NSTK patent application). He opined that the molecule would necessarily be larger for the long acting release formulation. I assume that would be because the exenatide is bound to the ALKS Medisorb. Is this the reason that you are wondering if a larger needle gauge may be required?<

I don’t think the molecule size is the issue—even the largest molecules are much smaller than the needle diameter. I think the main issues for the needle-gauge selection are the viscosity of the solution and the required needle strength, which depends on where the needle has to go.

>Are you of the opinion that a same or similar pen injection system could not be used with exenatide LAR?<

I would be very surprised if the Byetta pen could be used for LAR. First, the volume of drug needed for a weekly dose may be too high for subcutaneous administration—there is only so much fluid than can be taken up subcutaneously.

Second, if LAR has to be injected into muscle, a stronger (i.e. wider) needle than the one used for Byetta would presumably be required. (The last thing you want is to have a piece of the needle break off in a patient’s muscle.)

Third, the viscosity of the LAR solution may require a wider needle, although I do not know if this is the case. Even if this is not the case, the two points mentioned above suggest a different needle for LAR than for Byetta.

The main point in all this: whatever the right needle for LAR may be, AMLN and LLY are on record saying that the choice has not yet been made. That is what I find most revealing. Regards, Dew
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