With the expiry of patents for the blockbuster molecules looming large, the camps of big pharma giants are in disarray. The brain-storming strategies and policies pertaining to evergreening of these patents may be seen in the days to come.

Some of the big names in the game include the likes of Pfizer Inc., Merck & Co. Inc.’s, Bristol-Myers Squibb Co.’s and last but not the least AstraZeneca PLC’s.

These pharma giants own the drugs called as statins which lower the Low-Density-Lipoproteins (LDL) or bad cholesterol in the body. Statins are competitive inhibitors of HMG CoA reductase, the rate-limiting step in cholesterol biosynthesis. They occupy a portion of the binding site of HMG CoA, blocking access of this substrate to the active site on the enzyme. Currently available statins in the United States include lovastatin, pravastatin, simvastatin, fluvastatin, atorvastatin and rosuvastatin.

The global statin market in 2001 was valued at around $19bn led by Zocor and Lipitor. These two drugs generated total global sales of $12bn and accounted for approximately 70% of the global statin market. In 2002, AstraZeneca’s third generation statin, Crestor (rosuvastatin), received its first approval by the Medicines Evaluation Board (MEB) in the Netherlands. This approval initiated the arrival of the new “superstatins” into this maturing market. The withdrawal of Bayer’s Baycol (cerivastatin) has heightened awareness of the adverse effects of statins and has meant that considerable emphasis has been put on the safety concerns surrounding high doses of rosuvastatin and pitavastatin. Therefore, the lack of long-term safety data for third generation statins limits their uptake.

Patent expirations of three blockbuster statin drugs — Zocor, Pravachol and Lipitor between 2006 and 2015 will slash down more than half of the $27-billion (U.S.) annual market for lipid lowering drugs, of which 85 per cent was generated by statins, as a treatment to prevent cardiovascular disorders such as heart attacks and stroke. (By: British market research firm Datamonitor PLC)

Lipitor is one of them which need no introduction…thanks to Ranbaxy-Pfizer litigations worldwide with court decision(s) still pending around. Rest of the statins due to expire in the line are Merck & Co. Inc.’s Zocor and Bristol-Myers Squibb Co.’s Pravachol.

Innovative – Strategies of Innovators to keep generics at bay:

PLAN A) New Drug Development:

The most promising development is Pfizer’s CETP-inhibitor drug torcetrapib, which is being tested in combination with Lipitor, the world’s best-selling drug, with sales last year topping $12- billion. Torcetrapib works in the body by raising the levels of “good” cholesterol or HDL along with lowering of the LDL levels thereby arming the medical fraternity to deal with cardiovascular problems in a dualistic manner. But despite its promising efficacy, some analysts remain cautious because the Pfizer medicine can also raise blood pressure.

Pfizer’s plans to launch the new drug by 2009 as lipid lowering cocktail along with its winning horse Lipitor. Later it may sell torcetrapib on its own. But with generic Zocor around, it may eat away the profit margins of existing Lipitor as it is cheaper and an equally potent alternative in some cases.

Earlier this year, AstraZeneca claimed that its Crestor drug has the ability to reverse plaque buildup. Previous studies indicated that statins can only slow or halt plaque buildup.

Further it’s suspected that Merck has been testing its own CETP-inhibitor drug, even though the company has declined comment. AstraZeneca also paid $50-million to AtheroGenics Inc. last year to license its atherosclerosis drug candidate AGI-1067, which is now in late-stage clinical trials, with promises of another $950-million if the drug wins regulatory approval.

PLAN B) Over-the-counter (OTC) Switch:

It’s not long before AstraZeneca uses this weapon to fend off the generics with its money-spinner molecule omeprazole. The same can be speculated for the class of lucrative statins. Pharma experts are of the view that statins are a complex product because regular office visits are required to monitor cholesterol levels while being treated. Industry observers say that Merck’s Mevacor and Bristol-Myers Squibb’s Pravachol applications for OTC status were initially rejected because of these complexities. However with many blockbuster statin products approaching patent expiration, the industry will likely increase its OTC efforts.

State efforts for the OTC switch are driven by the growing statin market size. While the FDA previously refused to approve statins for OTC use, the administration has now signaled that it may be willing to reconsider its previous decision.

Future of statins:

It is estimated that around 10 million patients in the US are on statins, and recent federal guidelines estimate that as many as 30 million Americans may need to take a cholesterol- lowering agent to reduce the risk of heart attacks.

Today’s post comes from Gautam Bakshi, Manager – IPR, Intas Biopharmaceuticals Ltd., Ahmedabad, Gujarat, India (Gautam.Bakshi – at – intasbiopharma.co.in).

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