Chantix Side-Effects May Halt Rare Pfizer Success Story

Having been touted as one of Pfizer’s (PFE) few pipeline success stories in recent years, sales expectations for smoking cessation drug Chantix look set to be reined in following a number of high profile side-effect warnings, the latest coming Wednesday in a report suggesting a link to heart problems, seizures and diabetes.

The US pharma giant will be cursing its luck considering Chantix has represented the group’s biggest product forecast upgrade by analysts over the last 12 months, with estimates for 2012 almost doubling to $2.28bn, due to rapid uptake since its launch in August 2006. This upgrade to consensus forecasts represents the tenth largest by sales in the industry over the last year, according to archive forecast data from EvaluatePharma.

Wednesday’s report by The Institute for Safe Medication Practices [ISMP], released after market, prompted the Federal Aviation Administration to ban its pilots and air-traffic controllers from using the drug, as a result of a possible link to behavioral problems and drowsiness.

Despite the fact that the report has not been subject to peer-review scrutiny and published in a medical journal, or that establishing a causal relationship between a drug and a side effect is extremely difficult, the furore has left its mark, with Pfizer’s shares at a 10-year low of $19.53.

Revised consensus

Pfizer updated its Chantix label in November, and then more prominently in January, to include warnings about serious psychiatric effects such as depression and suicidal behavior.

The FDA is already conducting a safety review of Chantix, issuing an advisory statement in February that a link between use of the drug and adverse psychiatric events seems “increasingly likely”. The regulator’s response so far to this latest report is that current staffing shortages at the FDA mean a wider safety review, to include these additional possible side-effects, is not possible in the near future.

All of which means that sales growth in the first quarter showed signs of slowing down, with sales actually lower than the previous fourth quarter of 2007. US sales in the first quarter were $193m, representing 70% of global sales.

click to enlarge image

MAT = moving annual total (sum of previous four quarters)

Revised consensus forecasts, due to be published in EvaluatePharma later this month, suggests the downward revision has already started, with a 10% reduction in 2008 worldwide sales to $1.26bn.

How much further these forecast reductions are likely to go remains to be seen, but some analysts have so far suggested downgrades by as much as 30%, in light of the ISMP report.

Crucial to Pfizer

The importance of Chantix to Pfizer cannot be underestimated given it is the group’s second biggest growth driver over the next five years behind Lyrica, a treatment for various neurological disorders including epilepsy and fibromyalgia.

The drug also represents the company’s fifth most valuable product, with a consensus NPV of $6.17bn, equating to around 5% of Pfizer’s latest share price. As such, any reductions to the potential sales of the drug will have a significant impact on future cash flows, all the more critical once Lipitor is exposed to generic competition in 2010.

Investors will therefore be hoping that the company can quickly counter-balance this latest negative news and reinforce the risk-benefit profile of using their drug to quit smoking. If the issue continues to snowball, the knock-on effect to sales in Europe and Japan, where it has just been launched, could hurt the company further.

Disclosure: none

Comments

[fatcat:]

My ex-wife is a fairly normal woman(hmm)...she took this drug for a couple of weeks and said it was a very strange experience. One other friend said the same.It must really have some problems,so too Pfizer..

2008 May 25 05:46 AM

[gratefulino...:]

Lack of peer review and journal publishing should be factors. Chantix said it worked for 44% - an honest assessment and one to be respected. Thank God for Chantix. After smoking 461/2 years, it helped me quit. (A drug alone cannot do this - there is also a mind game involved.) I did have some strange dreams, so my doctor cut back on my dosage - which solved that. I was also taken off my blood pressure meds! so my heart was not suffering - except from , it would seem, smoking.

2008 May 26 12:20 AM

[no guinea pig:]

My husband took this drug for about 1 month and ended up in the hospital. He had extremely high blood pressure, couldn't remember the names of his mother, children, or siblings, and thought I was his nurse (we've been married 22 yrs.). Seems he had a mini-stroke. He had to have surgery a week later for a blocked artery. He'd never had any health problems before. So, your guess is as good as mine. Was it the Chantix? I'm suspicious. Maybe all new comers should have a complete heart check up before taking this drug. Then if problems suddenly occur, you'll have a better idea who and what is to blame.

2008 May 26 03:53 AM

[BlueOkie:]

no guinea pig,
Maybe you should change doctors if your doctor prescribed a drug without having done a complete checkup on your husband. If your husband was in great health before, I see a big lawsuit in your favor.

2008 May 26 10:31 AM

[jim collins:]

My friends that have taken it have reported outbursts of anger and irritability.

2008 May 26 12:57 PM

[User 199851:]

Your attitude and the trial lawyer-generated law suits are one of the reasons medicines in the US cost more...who do you think pays for greed?


On May 26 10:31 AM BlueOkie wrote:

> no guinea pig,
> Maybe you should change doctors if your doctor prescribed a drug
> without having done a complete checkup on your husband. If your
> husband was in great health before, I see a big lawsuit in your favor.
>
>

2008 May 26 04:54 PM

[User 199851:]

This report illustrates my opinion (and experience) that most Americans are ignorant about science, health, medicine...if you just assume that sitting in a doctor's office for a 'physical',etc. while not taking responsibility for your OWN behavior (the diseases caused by smoking/2nd hand smoke) have been well researched and documented/publicized!
A blocked artery, malignant hypertension, do not occur suddenly, but have been developing for years. Lifestyle choices are #1 in causation!


On May 26 03:53 AM no guinea pig wrote:

> My husband took this drug for about 1 month and ended up in the hospital.
> He had extremely high blood pressure, couldn't remember the names
> of his mother, children, or siblings, and thought I was his nurse
> (we've been married 22 yrs.). Seems he had a mini-stroke. He had
> to have surgery a week later for a blocked artery. He'd never had
> any health problems before. So, your guess is as good as mine. Was
> it the Chantix? I'm suspicious. Maybe all new comers should have
> a complete heart check up before taking this drug. Then if problems
> suddenly occur, you'll have a better idea who and what is to blame.

2008 May 26 05:12 PM

[dsr8time:]

Well, I see that if you are a pilot, airtraffic controller, train operator, truck driver, bus driver, you will not certified to be medically certified to hold the proper federal license. What is next you ask? Automobiles! Makes sense to me, this medicine is not safe!

2008 May 27 04:11 PM

[calatt:]

www.usatoday.com/news/...

I just read the above article on Chantix. This quote is interesting:


"..posted online by the non-profit Institute for Safe Medication Practices. Co-author Curt Furberg, a Wake Forest University medical epidemiologist, said he and his coauthors felt "this was too important" to submit first to a medical journal, which could take six months or more to publish."

Wake Forest University (WFU) is located in Winston-Salem, North Carolina, which also happens to be the home of the RJ Reynolds Tobacco Company. In fact, WFU sits on land donated to it by Mary Reynolds (then owner of RJ Reynolds) and Reynolds Trusts and the company have always been generous supporters WFU.

Why, of all universities, did WFU conduct this research? The conflict of interest on the part of WFU is palpable. Mr. Furberg thought this was of "too important" to submit to medical journals (who would examine sources) but perhaps the media would not be so picky. To important to who? In my opinion to RJ Reynolds Tobacco Co. and the tobacco interests who are trying very hard to trash Chantix.

2008 May 27 09:18 PM

[jwaydog:]

Let's face it....smoking kills people. Therefore, if you are taking this drug you were already crazy for being a smoker.
It is amazing that people are trashing a drug which has been extremely effective at weaning smokers. By the way, have I mentioned that SMOKING WILL KILL YOU. Bad dreams, odd behavior, so what!

2008 May 28 12:29 PM

[Abe Mishima:]

As a scientist, I offer two possible theories. One is that cigarettes are an anti-psychedelic, i.e., they suppress otherwise natural tendencies in some people to hallucinate. When such people stop smoking, they hallucinate. Theory two posits that Chantix can act as a psychedelic, in certain individuals, whether they smoke or not. I will ask my physician to prescribe the drug, and if it does give me strange dreams, I will order a multi-year supply, in case they ban the drug. I am not a smoker (but for the sake of obtaining the medication, I will buy a pack of cigarettes and attempt to smoke in the doctor's office.)

2008 May 28 03:14 PM

[happycamper:]

I am a female who has smoked for 40 years. Started in college and smoked at least a pack a day. Started Chantrix last Oct. and smoked a few puffs a day until mid-Dec and I quit. I had tried everything to quit before and so what if I had some odd dreams. (My family enjoyed my nightly adventures) and an upset stomach - I haven't smoked since I quit - and I don't have any desire to smoke!!!!!!! I can't believe I am smoke free - no more tar and nicotine and whatever else was in me - ick

2008 Jun 11 04:26 PM

[User 212891:]

My husband just got out of the hospital yesterday. He was experiencing severe muscle spasms, tremors in his arms and severe headaches. They did cat scans, MRIs, numerous blood tests, EEG, EKG and they have no idea what is wrong with him. The only new thing was the Chantix he started taking 2 weeks ago. The symptoms started to occur just after the increased dosage. Has anyone else had reactions like this?

2008 Jun 19 02:25 PM

[Smoke-Break:]

Chantix is the only drug or device presently on the market that's any good at helping smokers quit smoking. I hope they don't pull it, or "lawsuit" it to death. NOTHING kills or hurts people like cigs. Chantix should be prescribed only by the most attentive of physicians, and discontinued immediately if there are any side effects. Soon there will be other quality products for smokers, but right now, only Chantix is any good.

2008 Jun 30 06:12 AM

[bobble head:]

I took Chantix and developed a headache so severe that I felt like it was a pressure-cooker ready to explode. I went to the doc's. He ordered an MRI immediately. It showed I had had a couple of mini-strokes. There is no doubt in my mind Chantix caused it. My head shakes from side to side now, my children call me "bobble head" and my students ask me why I shake my head. I only notice it when I'm doing something tedious such as putting on eye liner or lip liner.

2008 Jul 18 11:52 PM

[Mandie:]

I took this medication for about a month and a half. All I remember was that it made me feel like a zombie. I would black out while driving. I would have a hard time concentrating at work. It took four months for me to feel somewhat normal again. And no, I didnt quit smoking. This medication screwed with me so hard I wouldn't reccommend it to anyone.

2008 Nov 17 10:49 PM

[Oldladywho:]

I smoked for 30 plus years. I quit with Chantix, but I wish I had tried first to quit on my own. I was offered the Chantix, and I took it from my OB/Gyn. 4 months later, I could no longer eat or sleep and was hopsitalized for extreme depression/anxiety. They kept asking: "are you sure you've never been depressed before? "No." "Anyone in your family suffer from clinical depression?" "No." They tell me it will take 3 to 5 years to recover. I have lost my job. I sure would love a cigarette, but I can't afford that anymore. :) Who knows if it was Chantix? My Psychiatrist feels strongly that it may have been. The public should be forewarned.

2008 Nov 22 10:56 AM

[kimster:]

I have tried several times to quit smoking. I have cancer on both sides of my family and though we're financially strapped, I still smoke. I got my prescription for Chantix... been on it a week. I have read all of the information that came with the medicine, but what it doesn't say is that you can experience what seems like a bad acid trip when mixed with alcohol. So after reading the above it seems like I have a choice... die of cancer, or possibly a stroke... I don't know what to do... but I think more research needs to be done on how this affects people.

Jan 25 02:26 PM

[mandy:]

"so what"!
my 21 year old neice is in a psych ward right now because of chantix and who knows if she will ever come out of this state of mind.
"so what"?


On May 28 12:29 PM jwaydog wrote:

> Let's face it....smoking kills people. Therefore, if you are taking
> this drug you were already crazy for being a smoker.
> It is amazing that people are trashing a drug which has been extremely
> effective at weaning smokers. By the way, have I mentioned that SMOKING
> WILL KILL YOU. Bad dreams, odd behavior, so what!

Apr 16 06:15 PM