Heartfelt with Dr Melissa Walton-Shirley

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The HDL ceiling: Cracked today by DEFINE and the CETP inhibitor anacetrapib

Nov 17, 2010 12:33 EST


Because lifestyle modification is the ever-elusive holy grail of plaque stabilization, and because those of us who've been ravaged by years of self-imposed endothelial battering need help in a hurry, we continue our quest to find the perfect solution to the prevention and treatment of coronary artery disease. Today's presentation by Dr Chris Cannon was elating to say the least. The HDL levels went out the roof with the oral selective CETP inhibitor anacetrapib. As a matter of fact, those patients had so much HDL, they were swimming in it, achieving a level of over 100 with a simultaneous reduction in LDL levels. It was every cardiologist's fantasy, but it was also a little unnerving. It was kind of like, after finally being taken to the zoo you found yourself behind the glass, standing right in the middle of a legion of quiet gentle gorillas but with a dangerous and aggressive potential. We all remember the torcetrapib outcome; flying high with its HDL-raising capabilities but shot down by elevated blood pressure, mortality, and cardiac events, the outcome of which for some was devastating. This compound was different, though, and it didn't just scoot by with marginal data, it soared! And with no safety concerns as well. I don't think in my seven years of being with theheart.org that I've come out of any meeting so optimistic. Well, except maybe one other time. That was in 2003.

I attended a small abstract presentation somewhere in the world that reported on the infusion of recombinant DNA with the same gene sequence as HDL. The study had 47 patients suffering from unstable angina who were then evaluated by intravascular ultrasound (IVUS), and "voilà!" the first "Drano effect" ever with any compound in history, effectively unplugging vessels to a statistically significant "p-value" degree. I left thinking we were now on a Star Trek–like course with key in hand to the universe of MI prevention. It is now 2010, and I'm still waiting, at least I was until this morning.

I did ask the question why it was that we veered off course with the IV preparation that produced IVUS-proven plaque burden reduction and therefore presumed stabilization. The answer was that the compound, ApoA1 Milano, was difficult to manufacture, and apparently there were some hypersensitivity concerns and then problems with delivery. Who wants to infuse anything when you could take it PO? However, I had fantasized that perhaps we could infuse it during unstable-angina admissions or PCI procedures or at least until we learned how to reproduce the same effect with an oral preparation.

That's the hope for today's anacetrapib, the new CETP inhibitor. It's a whole new drug class, and instead of cracking its head on the HDL ceiling, it smashed through it and kept on flying. An upcoming trial in the not-too-distant future is planned to look at event rates. For my birthday present next year, I hope they plan an invasive IVUS arm to actually look at what's happening to plaque volume and power the trial to look at hard primary end points like death and MI. I quipped that a safe HDL-raising compound could be "the gift that keeps on giving," to which someone who is a rather tall, articulate gentleman who wears wire-rimmed glasses, works at a well-known center in Baltimore, MD, and whose initials are RB, quipped, "Yeah . . . like venereal disease," meaning we hope that it's proven to be an effective compound that will infiltrate, like wildfire, every echelon of lipidology.

Well said, my friend who shall remain nameless, well said. And remember, you did say I could quote you! :-)

See also:

DEFINE: Large effects on LDL and HDL cholesterol with CETP inhibitor anacetrapib








Your comments
The HDL ceiling: Cracked today by DEFINE and the CETP inhibitor anacetrapib
# 1 of 9
November 18, 2010 02:34 (EST)
Deepak Natarajan

An excellent blog as usual...... ..but, at the risk of being termed a prude, for the inappropriate analogy at the end. 

 

# 2 of 9
November 18, 2010 07:40 (EST)
Melissa

Deepak,

You aren't a prude. I think we were  just giddy with excitement at this very positive trial. thanks for your compliment and for reading!!!

Melissa

# 3 of 9
November 18, 2010 12:58 (EST)
Roby Mitchell MD
The "Drano effect" was demonstrated long before 2003. Dean Ornish showed it in his book in '95 and Caldwell Esselstyn at the Cleveland Clinic has validated the effect. You'll never medicate people out of diseases they behave themselves into. Vascular disease is underwritten by an inflammatory response in the vascular endothelium that was very rare until the 19th century. It is the same immune system generated inflammation/oxidation response that is responsible for most chronic diseases from asthma,to Alzheimer's. Peter Libby and his group have documented this too well. The same cascade he describes is repeated when you study the literature across sub specialties. We're not dealing with diseases but consequences.Can you imagine a pill to treat the consequences of drunk driving? The pharm industry has taught of the art of pandering for profit-"The Emperor's New Clothes". Surgeons doing gastric bypass see plaque reversal and a cure of diabetes. Not because of weight loss,but because they mitigate the inflammation/oxidation process by reducing the substrate the inflammation generating microbes feed on.
# 4 of 9
November 19, 2010 10:37 (EST)
J.S.
Spot on Dr. Mitchell.  When will we learn?  Food is our best medicine.  Real food, not the processed garbage we are told to buy on TV and in print ads.
# 5 of 9
November 19, 2010 12:41 (EST)
jsteward
LET'S SEE WHAT PRICE THE PHARMACEUTICAL INDUSTRY PUTS ON THIS MEDICINE! HOW ABOUT A  SOME HEALTH CARE REFORM TARGETING THE PHARMACEUTICAL INDUSTRY AS WELL.
# 6 of 9
November 20, 2010 12:51 (EST)
W.E. Feeman, Jr, MD
After the torceprabib affair, I won't trust any drug that markedly elevataes HDL, unless it proves that the marked rise in HDL is a marked rise in "functional " HDL, and proves it by an outcomes study.  I would accept an IVUS study showing a decrease in plaque cholesterol volume.  Remember that torceprabib did wonders for the lipid profiles but had no effect on plaque volume.  Also, I have seen patients with high levels of HDL and middling levels of LDL have atherothrombotic events--some were alcoholics and two took Dilantin....As to delipidated HDL, Apo-A1 Milano, and maybe even oral D4F--I would be happy to use them as soon as they are shown to be safe since the evidence shows that they will indeed decrease plaque cholesterol volume.
# 7 of 9
November 22, 2010 09:43 (EST)
Stephen Brown, PhD
Just to clarify some details in the comments to date regarding anacetrapib.  First of all, apoAI-milano is a recombinant PROTEIN complexed with lipid, not recombinant DNA.  Pfizer recently out-licensed this therapeutic to The Medicines Company.  Secondly, I concur with Dr. Freeman that HDL-C clinical measurements raised by CETP inhibition, mechanistically, are not sure to result in functional HDL particles that would provide true clinical benefit.  Anyone who cares to undertake a critical review of the scientific literature will be become more skeptical on this point.  I'm very much looking to a clinical trial of anacetrapib measuring hard clinical endpoints, period.
# 8 of 9
November 23, 2010 09:08 (EST)
Melissa

Thanks Stephen,

I took that descriptor directly from a report I read and I've heard it referred to in that manner as well....but I appreciate your clarification and your post.

Thanks for reading.

Melissa

# 9 of 9
November 27, 2010 02:10 (EST)
Richard Maloney M.D.

Anacetrapib also had a huge effect on reducing Lipo(a). Potentially reducing atherogenesis directly or via improving RCT.

Niacin has limited benefit and apheresis is not fun or cheap 

 


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About Dr Melissa Walton-Shirley
Dr Walton-Shirley performs invasive cardiology, nuclear cardiology, and stress echocardiography in a private practice in Glasgow, KY.

Her chief medical interests are CHF/hypertrophic obstructive cardiomyopathy and the promotion of primary PCI for acute MI. Recently she played a significant role in helping to launch an ambitious pilot study of primary PCI in Kentucky, the Kentucky Primary Angioplasty Pilot Project. She has also participated in the TIMI 19, Duke-HF, NRMI, and CRUSADE trials and is proud to have been an advocate of the first smoke-free initiative in Kentucky (2011). She champions a smoke-free America.

Dr Walton-Shirley received her undergraduate degree at the University of Kentucky and went to medical school and did her residency and fellowship at the University of Louisville. She is married with two daughters. Her interests include singing, writing poetry and songs, fitness, and, of course, theheart.org.