Immunogen’s T-DM1 gets presidential treatment

Immunogen (IMGN) is still trying to recuperate from the controversial rejection of T-DM1’s accelerated approval filing. The message Immunogen was trying to convey is that nothing has changed in terms of T-DM1’s long term potential. According to the company, the FDA’s problem was not with the drug’s stellar activity but the patient population enrolled on the trial. In just over a week from now, it could have the data to prove it.

Although the next potential filing is expected only in 2012 based on an ongoing phase III trial (EMILA study), T-DM1 will have two important data readouts at next month’s ESMO conference. The first is a phase II study where it is compared to chemotherapy+ Herceptin, the current standard of care for 1st line breast cancer patients. As I reviewed last month, expectations from this trial are high given Roche’s decision to start a pivotal trial based on a similar trial design.

Now investors have another reason for optimism: T-DM1’s 1st line data is included in the presidential symposium, to be held on October 11th. Organizers typically put the most interesting presentations in this kind of sessions, so it is safe to assume the trial is not a total flop. Just to give a sense of the profile of this session, other presentations in the presidential symposium  include Cougar’s phase III in prostate cancer and a phase III study of Avastin in ovarian cancer. Both studies have already been touted as successful. As a result, investors could expect T-DM1 to be safe and active as a 1st line treatment.

Another important readout is from the 3rd line phase II trial that served as the basis for the accelerated approval application which was declined by the FDA. Top line results were already presented last December, with an impressive response rate of 33%. At ESMO, the most important piece of data in the trial will be updated progression free survival (PFS) numbers. This will shed more light on T-DM1’s prospects in the ongoing 2nd line phase III trial. At the last update, median PFS was ~7.3 months but this figure excluded many patients who were deriving benefit from T-DM1 and still had not progressed at the time. Therefore, updated numbers could be better than 7.3 months.

In summary, the ESMO conference should prove once again that T-DM1 is highly active and that fundamentally, T-DM1’s prospects have not changed as a result of the recent rejection.

Another important readout for Immunogen will be updated results for IMGN901 in Merkel Cell (MCC), a niche indication but also a potential fast route to market. To date, results in MCC were intriguing but somewhat ambiguous (discussed here under ” Looking beyond T-DM1″). The market’s expectations for this agent are low, so any positive data will be a pleasant surprise.

6 thoughts on “Immunogen’s T-DM1 gets presidential treatment

  1. Hi Ohad,
    Great post as usual, but will Roche/Genentech file again for TDM1 even if the results prove higher pfs and establish patient population? I doubt it as another rejection would be a major setback and theyve had few with Avastin recently. Most investors have flown out of imgn not based on results of the PII trial, but more that it is dead money for 2 years. I doubt this will change, but you never know.


  2. SGN 35 met study’s goal and plan to file for approval in first half of 2011. It seems like many are much more optimistic on SGN 35 than on TDM1 so the stock is up almost 25% in just the last 5 days. Is this optimism warranted? Is SGN 35 superior to TDM1? What do you think the value of SGEN shares should be worth?


  3. Thanks, Manish.
    I don’t suppose Roche will seek approval before 2012, no matter how positive the data set is.
    It is true that no filing application is expected in the coming 2 years but the company is looking at additional potential catalysts (for good or worse) until then.



  4. Sam,

    SGN-35 results are spectacular, I am very curious to see duration of response numbers but this is a true breakthrough. The reason why people or more excited about SGN35 is because it will be on the market next year in contrast to T-DM1 which will have til 2012. The two drugs do not compete and have no mutual effect.



  5. Hi Dan,

    Actually I plan to publish a post on ARRY which was prepared before the ARRY380 data came out. The post will discuss other interesting assets Array has.

    The 380 data looks interesting but very early. The value of the drug is in combination with Herceptin and head to head vs. Tykerb. In theory this drug could be very meaningful as the only selective HER2 inhibitor (selective compounds are all the range right now…)but there is not enough data. The p1 results cetainly merit a phase II study.

    Unfortunately, Friday’s news prevent me from adding a new position in Array as I can only make changes on sundays assuming no meaningful data are published after market close. As a result, I plan to add more ARRY to the portfolio next week as part of a write up on SGEN.



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