If the patent cliff were a sports team, Pfizer’s cholesterol- lowering drug Lipitor (atorvastatin) would be its mascot. Because it’s the top-selling drug, well, ever — with 2010 sales well in excess of $7 billion in the United States alone — Lipitor’s loss of patent protection on Nov. 30, 2011, didn’t start or end the patent cliff but in many ways symbolized it.
“We’ve never had an $8 billion drug go off patent before, and you don’t know whether it’s a one-off or not a one-off,” IMS Health VP industry relations Doug Long told Drug Store News. “And I think only time will tell.”
This year, several more top-selling drugs will lose patent protection. These include Bristol-Myers Squibb’s and Sanofi’s blood-thinning drug Plavix (clopidogrel), the No. 3 drug, with $6.1 billion in U.S. sales in 2010, according to IMS; AstraZeneca’s antipsychotic and antidepressant Seroquel (quetiapine), with sales of $4.4 billion; and Merck’s allergy and asthma drug Singulair (montelukast), with sales of $4.1 billion.
But a couple of factors have entered the mix: One is Pfizer’s efforts to protect Lipitor beyond patent expiration, which included an authorized-generic deal with Watson Pharmaceuticals to compete with Ranbaxy Labs’ generic version and a deal with pharmacy benefit managers to require dispensing of branded Lipitor instead of the generic, though this deal attracted some scrutiny from Congress. Another tactic Pfizer is pursuing is an OTC switch for Lipitor, though the outcome of this remains far from certain, as previous attempts by other companies to sell statins over the counter have proven unsuccessful.
Later in the decade, after the patent cliff ends, Long foresees an “innovation drought” that could adversely affect the generics industry. Drug companies will concentrate on specialty drugs instead of primary care drugs, forcing generic drug makers to step up their pursuit of newer sources of revenue like follow-on biologics.