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Ohad Hammer

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  • Immunogen's Bright Future (Part II) [View article]
    Hi Gary

    You are right, the Antibody -drug link in DM4 conjugates is more sterically hindered than DM1. Both can be used, but the decision to use one or the other should be taken for every case specifically. You are also right about additional toxic molecules like synthetic taxanes and DC's. I may be wrong here but the last immunoconjugate based on DC1 was the anti-B4-DC1, which targets CD19 ( I am not sure if that is the antibody they used in SAR3419...), and that was published in 1995. The reason DC's haven't been mentioned in a while is that DC1, the first generation of DCs had a very poor solubility in water, making development very hard. This problem may be solved in the newer version (DC4) which is much more soluble due to a phosphate group attached to the drug. I haven't heard anything else

    About the huC242-DM1 trials, in the first trial, there were two patients with +30% reduction in tumor size and several stable disease cases, but I guess that wasn't enough. Don't forget that eventually most drugs will have to be compared with approved drugs and even if approved, they will face tough competition from existing treatments in the market. In the second phase I trial of huC242-DM1, all responses were among non colorectal cancer patients. Bear in mind in both trials there were over 20 colorectal cancer patients, so it doesn't look too good, but perhaps better screening is the answer.

    The My9-6-DM4 story is very intriguing. With the limited data we have, why a company like Sanofi-Aventis would launch 2 clinical trials for this drug is beyond me, but let's hope they have a reason.

    Oct 19, 2007. 12:00 PM | Likes Like |Link to Comment
  • Immunogen’s Bright Future [View article]
    hi druggie

    There is no doubt T-DM1 is a very promising candidate, and I kinda tohught my article conveyed that message, especially the last sentence.

    About the objecitve response rate, there were 15 patients who received 3.6mg/kg and one who received 2.4mg/kg. that's a total of 16. Even according to what you write:
    4/10+ 2/6 = 6/16 = 37.5%

    I don't understand why you refer me to Genentech's pressentation. I write my personal opinion and the fact that someone else thinks differently doesn't mean I have to think the same way. I think looking at pre-clinical trials is important since it included a comparative analysis between naked trastuzumab and T-DM1. Of course, nobody expects a drug candidate to behave in clinical trials like it behaves in pre-clinical trials, but some of the difference in potency was lost .
    Again, there is no doubt T-DM1 is more effective than the naked antibody, I just hoped it would be more potent, that's all.

    Oct 11, 2007. 04:31 AM | Likes Like |Link to Comment
  • Peregrine Pharmaceuticals May Be On To Something [View article]
    Hi Jimmy

    Sorry, but I don't follow AMGN specifically, although I am familiar with some parts of its portfolio and pipeline. Generally, I would have to go with Adam Feuerstein, whose opinion I appreciate very much, even though he is not too excited about Peregrine...
    we'll be much smarter after their R&D day 3 motnhs from now.

    Oct 2, 2007. 03:58 PM | Likes Like |Link to Comment
  • Peregrine Pharmaceuticals May Be On To Something [View article]
    Thanks for the comment JazzPal

    the strong macrophage infiltration and activity towards the core of tumors in mice ia very encouraging. However, I don't think we know enough to clearly state the MOA of bavi, although the interaction of PS with PS receptors on macrophage has been well documented.
    It's great to read your optimism regarding bavituximab's spectrum of use but you have to remember that no matter how promising any agent seems, it probably won't serve as a universal solution for every malignancy. there are many other known mechanisms by which tumors evade the immune system, so while PS might have an important role in that process, there are numerous other players.

    Sep 22, 2007. 04:19 AM | Likes Like |Link to Comment
  • Peregrine Pharmaceuticals May Be On To Something [View article]
    Hi John
    Thanks for your comment.
    The problem here is that we know patients have failed prior therapy, but we don't know exactly what kind of therapies. There are many regimens approved for the treatment of metastatic cancers, and it seems likely that the agents used in the trial were not the agents the patients had relapsed upon. Hence, we cannot give the credit to bavituximab.
    Besides, regardless of the past therapies,I stand by my first statement that this trial was not a comparative trial, becasue it simply wasn't, nor are the phase II trials the comapny is expecting to begin.
    A comparative trial must be a double blind, randomized trial with more a control/plcacebo arm.

    Sep 22, 2007. 03:44 AM | Likes Like |Link to Comment
  • Cell Genesys’ GVAX: A Multi-Trick Pony [View article]

    I am always happy to receive feedback regarding my articles, although I am somewhat disappointed by the fact your criticism deals strictly with semantics, instead of the ideas and claims expressed by the article.

    I still don’t see the poor taste in equating CEGE to a multi-trick pony.

    Aug 1, 2007. 09:54 AM | Likes Like |Link to Comment
  • The "Naked" Truth About Antibodies For Cancer Therapy [View article]
    Thank you for your great replies. IMGN is shaping up to be a true leader in the immunoconjugate field, but no one knows exactly when this market will kick into gear. I must admit, though, that their Trastuzumab-DM1 results have been far from being impressive imho. They haven't published a scientific article about this trial so perhaps it's too early to comment, but the results look as if it was just another naked antibody, instead of a highly toxic compound (cytotoxicity of maytansine is thought to be 200- to 1000-fold higher than that of other tubulin polymerization drugs like taxol, and its deriviatives, like DM1, are even more toxic). it doesn't imply their technology is inferior, it just means that they'll have to try agian and again until they make it. in drug development statisitics are alway against us, so many agents must be evaluated before finding a truly successful one.

    I am planning to write an article about IMGN but for now I am working on several other articles, including a SGEN article which (hopefully) will be published next month.

    Jul 8, 2007. 11:04 AM | Likes Like |Link to Comment