Hoping to penetrate an anti-platelet market dominated for a decade by Plavix, Eli Lilly and Daiichi Sankyo received FDA approval for Effient, but with a black box warning that will complicate promotional efforts.

The drug, launching in August, is indicated for the reduction of thrombotic cardiovascular events such as stent thrombosis in patients with acute coronary syndrome who have undergone percutaneous coronary intervention and have had a stent implanted.

Lilly officials point to data from the TRITON-TIMI 38 Phase 3 clinical trial as proof that treatment with Effient significantly reduces the combined risk of cardiovascular death, heart attack or stroke over the current standard of care, Plavix. However, positive data is offset by a boxed warning alerting physicians that the drug can cause significant bleeding.    

Nevertheless, Lilly plans to pursue an aggressive marketing campaign.

“We are going to use a variety of channels to communicate the Effient story to physicians, patients and payers,” said Troy Turner, Effient US marketing director for Eli Lilly.

Barbara Ryan, an analyst with Deutsche Bank in New York, said that the uptake for Effient will be slow and the boxed warning presents a challenge.

“They may have some penetration in new patients in an acute setting,” said Ryan who added that she doesn’t see a big opportunity for switching by physicians from Plavix to Effient. Ryan said that Effient is unlikely to penetrate Plavix market share in the short term, and in the long run, it will be facing competition from a generic version of Plavix, which comes off patent in 2012.

In response to potential problems that the boxed warning could present, Lilly’s Turner told MM&M that: “Bleeding is always going to be an area that people have questions about with respect to an anti-thrombotic medication. I don’t think that reflects poorly on us or takes anything away from the value and benefit that Effient brings in terms of innovation and potential benefit to ACS/PCI patients.”

Lorenz Muller, executive director, thrombosis marketing, Daiichi Sankyo, said that the boxed warning clearly defines those patients, as found in the TRITON-TIMI 38 trial, who might be at a higher risk for bleeding and therefore provides clear prescribing information to minimize the risk of bleeding. “Physicians will need to make a clinical judgment based upon the overall benefits and risks of the medication for each particular patient.”

Yet the question of whether or not physicians will switch their patients from Plavix to Effient is a key element to its success.  “Lilly has a real problem on their hands. On the one hand, they have a more effective drug, but on the other, they have a more expensive drug with more bleeding,” said Cam Patterson, MD, chief, division of cardiology, UNC Healthcare, Chapel Hill, NC. Patterson added, “I don’t think there is going to be a lot of cardiologists willing to make a wholesale switch to prasugrel.”