Replies to post #35557 on Biotech Values

[DewDiligence]

Re: Structural differences Lucentis vs Avastin

>They're really the same thing, but the NEJM figure cuts a few corners. Understandable since few docs would really care how the antibody was made, as long as it is efficacious.<

OK—agree that few readers actually care about these cut corners, but I do for my own education! Moreover, I think the structural differences between Lucentis and Avastin are inevitably going to come into play from a business standpoint when head-to-head data come out from the NIH study.

Currently, DNA can get by with saying that they know Lucentis is safe and effective, but they do not know if the same is true of Avastin in AMD.

However, if there are data in a few years from a randomized trial that show Avastin is safe and effective in AMD, then DNA may revert to making the (perhaps bogus) case for Lucentis based on its structure and origin.

What I find remarkable about the structure and origin part of the Lucentis vs Avastin debate is that the ~70% reduction in molecular weight of Lucentis compared to Avastin and the multiple-pass optimization of Lucentis’ VEGF binding affinity have apparently produced much less of a clinical benefit than the drug developers envisioned.

Does this imply that drug optimization is even more of a misnomer than most investors think?

[Biowatch]

Re: Lucentis vs Avastin

PGS is right in that the illustrations are simplified depictions of the design process. Presumably most doctors don't care how they were made, just the affects of the final product (clinical trials results, PK data.)

Both omit the humanizing/chimerizing step that involves recombinant DNA, and many other technical, albeit standard, procedures involved.

Edited to add: I don't know what the relative yields and costs are for producing the two drugs. That may be significant too.

In terms of drug optimization, sometimes that is a matter of luck, dependent on how long you test and screen and how good your screening method is.

[ghmm]

Dew/Gradstudent,

Not to butt in on your good discussion but a question on MAB's. I do not have a science background and was wondering on your thoughts on the different types of MAB’s in particular Murine. I am familiar with the Nature Biotech article that is critical of the poor success ratio of Murine MAB’s (“Monoclonal antibody successes in the clinic” http://tinyurl.com/y66766) but it is my understanding that a mouse MAB would be something the body would (more easily) recognize as foreign and thus more likely to mount an attack against it which seems desirable in an indication like cancer. Not sure if that is how Zevalin/Bexarr work but it sounds logical to a non-science guy anyway.

I guess what I am getting at is do you feel one type of MAB (Human/Humanized) is better in general (could be unfair to generalize I know) or are there characteristics of Chemeric and Murine that make them suited for certain indications.

Thanks in advance!