Elan's and Wyeth's Data: Success or Failure?

Sometimes, early stage data from a clinical trial can help inform investors about the prospects of a drug, and sometimes the data just makes a drug's future even harder to gauge. On Tuesday, Elan (NYSE: ELN  ) and partner Wyeth (NYSE: WYE  ) released new mid-stage data for their potential blockbuster bapineuzumab (AAB-001) for Alzheimer's disease, and it doesn't make things any clearer.

It's important to remember that the hurdles for a successful phase 2 clinical study are not the same as for a phase 3 trial. In the bapineuzumab study, patients taking the drug didn't show a statistically significant improvement in the symptoms, but that can be OK in some cases.

After the study was completed, though, Elan and Wyeth did notice that a large group of Alzheimer's patients taking bapineuzumab and lacking a specific genetic characteristic did fare better on both effectiveness and safety issues. All we got was this headline information, and next month at the International Conference on Alzheimer's Disease, we'll get more information about how well this specific patient group performed compared with placebo and the other patients treated with bapineuzumab.

What makes Alzheimer's disease clinical studies and studies for drugs to treat other forms of cognitive impairment so tough is that there are often no definitive or irrefutable goals, like survival, on which to gauge a compound's effectiveness. This is why the success of Alzheimer's disease compounds is more unpredictable than normal and why many predict that these compounds will fail at a higher rate than other drugs. Compounds like Myriad Genetics' (Nasdaq: MYGN  ) Flurizan are in a similar murky situation, although at a much later stage in development.

That being said, the goal of any phase 2 study is to (at a minimum) help inform a drugmaker on how to design the more important phase 3 studies and what sort of data these phase 3 studies must produce to be a success. In this respect, preliminarily at least, I don't think the bapineuzumab study was a success, unless something more definitive comes out later this month -- especially considering that the companies have already begun multiple phase 3 trials.

Elan and Wyeth also noted that "there were imbalances" in this phase 2 trial that could have skewed its results. When you combine this with a small study size, murky trial endpoints, and unexpected post-hoc subgroup data, investors should feel just as ambiguous about bapineuzumab's prospects as they were before the phase 2 study data came out. Therefore, I think the risk of bapineuzumab failing in the clinic has not gone down. Invest accordingly.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has an A+ disclosure policy.


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  • Report this Comment On June 18, 2008, at 6:51 PM, mostlyconfused wrote:

    Huh....??? So statistical significance on several key endpoints in a group representing 40-70% of the AD population is a murky outcome?...uh, I don't get it bob....er Brian....let's ask the families of the patients whose test scores improved, eh?

    Efficacy Findings

    The study did not attain statistical significance on the primary efficacy endpoints in the overall study population. Post-hoc analyses did show statistically significant and clinically meaningful benefits in important subgroups.

    In non-carriers of the Apolipoprotein E4 (ApoE4) allele, estimated in the literature to be from 40 to 70 percent of the Alzheimer's disease population, post-hoc analyses showed statistically significant and clinically meaningful benefits associated with bapineuzumab treatment on several key efficacy endpoints, including the Alzheimer's Disease Assessment Scale (ADAS-cog), the Neuropsychological Test Battery (NTB), the Mini Mental State Examination (MMSE) and the Clinical Dementia Rating - Sum of Boxes (CDR-SB). A favorable directional change was seen on the Disability Assessment Scale for Dementia (DAD), although this was not statistically significant.

    Additionally in non-carriers, preliminary evaluation of MRI results showed less loss of brain volume among treated patients versus placebo patients, a finding that was statistically significant. Smaller increases in ventricular volume were seen in treated patients compared to placebo patients, although this finding was not statistically significant. Progression of Alzheimer's disease is generally associated with loss in brain volume and increases in ventricular volume. Further, treatment-related benefits seen on MRI were correlated to the favorable clinical changes observed in non-carriers.

  • Report this Comment On June 19, 2008, at 8:39 AM, abrown50 wrote:

    Brian it sounds like you have an axe to grind about anything having to do with Elan.Is that because you were completely wrong about Tysabri? Sounds like you're predictably on the same path again.Apparently your glass is always half empty.I think Elan's cup runneth over.The Alzheimers results were fantastic.The fact that they hit statistical significance in an important sub group in a trial that was not powered for this is remarkable.It shows a possible breakthrough for the first disease modifiing drug for Alzheimers.This offers tremendous hope for patients and their families throughout the world.No matter how positive the results are at ICAD I know you'll provide the pessimistic side of the equation.That's what you do best.

  • Report this Comment On June 19, 2008, at 9:35 PM, famc17 wrote:

    What bothers me about Elan's statement, is that they worded it so that if you didn't spend a little time reading between the lines, it sounded like their non-carrier patients improved cognitively. First off, The actual statistics on the ApoE4 gene are not really out since most AD patients have never been tested for it. So the 40-70% is just a guess. They should have told us the percentage of all the patients in the whole test that had the gene for a correct estimate. Let's just give it 50%. So, right off the bat, 50% of the test subjects were not helped at all. Thus, they came up with a group i.e. post hoc - the Non-carriers of the gene. In this "special" group, they said there was statistical significance. Well that's great if it meant patients improved. But, that's not what they said. They said it was statistical significance in test scores, which means they declined less rapidly as placebo subjects, as stated from another article where they said that the decline was 2 points as compared to 6 points in the placebo group:

    http://www.boston.com/business/healthcare/articles/2008/06/1...

    Also from the statement from Elan, they noted Less loss of brain volume, and smaller increases in ventricular volume -- This means they declined less rapidly than the placebo group, but still declined. Is that any better than Aricept or Namenda? Who knows, since they didn't give any specific data.

    So, why couldn't they just have come out in plain English and said:

    1. For non-carriers of the ApoE4 gene there is hope, especially as a preventative medicine to prevent the plaque from building up, or in very early stages of the disease so as not to have to remove too much plaque which can cause the brain swelling. In this group, they were some accounts of Brain Swelling but less than in the ApoE4 group, 2 point decline in 18 months as compared to 6 point decline in the other groups. Less Brain Loss and Less increases in Ventricular Volume as compared to Placebo and ApoE4 group, which also means less decline in the 18 months.

    2. No benefits for people with ApoE4 gene: *ApoE4 group: Some accounts of Brain Swelling, 6 point decline in 18 months

    *Placebo group: No Brain Swelling, 6 point decline in 18 months.

    There is another treatment that hasn't reached a Phase II trial because it has been held back by the Pharmaceutical Companies - Competition?? You Bet!

    The doctor is treating patients off-label since he couldn't get anyone to fund a double-blind clinical trial. He has trained approx 12 doctors to do the treatment across the country, and one in England!Patients DO improve a little on the test scores, then they hit a plateau and maintain. It started out as a 15 pateint study, and is growing everyday. My guess would be that there are about 80 patients receiving the treatment right now. The success rate is at about 80% which is astounding. So far, there have been several patients who have been maintaining for over three years.

    Please see the study results for Perispinal Etanercept (Enbrel)

    http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pub...

    before you invest in BAP. BAP may be great for people that are diagnosed early, or don't have the gene, but for all the others, Enbrel is going to be key. I think we're going to need both drugs working together.

    I am not a stockholder or an employee to anyone, I am the caregiver of my Mom who has been receiving the Enbrel treatment since March. Just trying to spread the word to other caregivers to get help for their Loved Ones.

    Thanks, Felicia

    famc17@yahoo.com

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