New York psychiatrist Jeff Lieberman has heard J&J’s sales pitch for its new Invega schizophrenia drug, but he’s not too impressed. The problem, he tells Dow Jones, is that Ivega isn’t much different than one of J&J’s best-selling drugs, the antipsychotic Risperdal.

In late June, Risperdal is scheduled to lose patent protection, clearing the way for cheaper generics, which could further diminish Invega sales, already characterized as a disappointment by J&J. “I don’t think they have a strong case to make,” Lieberman, chairman of the psychiatry department at Columbia University’s medical school, tells the news service. “It’s basically a me-too drug, and the company hasn’t done the studies that would be required to really distinguish it.”

Lieberman’s skepticism is shared by health insurers and points to a rising challenge for drugmakers - a tougher market for follow-on drugs, the news service writes. As a result, some, such as Wyeth and Shire, are setting prices lower or emphasizing improved dosing for newer drugs to help overcome any skepticism that they’re not much more effective than the older drugs set to lose patent protection.

The growing disdain for follow-on drugs also should reinforce the need for drugmakers to come up with truly innovative products, not just marginally better ones, Dow Jones adds. Pharma has used follow-on meds to offset revenue lost when older, top-selling drugs lose patent protection and become exposed to generics.

A successful example was AstraZeneca’s promotion of the Nexium heartburn pill when its older Prilosec became exposed to generic competition in 2002. Nexium went on to become a huge blockbuster despite being chemically similar to Prilosec, which became available as both a cheaper generic and an OTC product.

Such tactics, however, might not work as well in today’s environment, in which pharmacy benefit managers and insurers are demanding steeper discounts and pushing generics. “We don’t think those opportunities are really going to fly,” Deutsche Bank analyst Barbara Ryan tells Dow Jones. “I think managed-care sees them for what they are, extending the franchise.”

The skepticism around Invega has contributed to a financial disappointment for J&J, which hasn’t broken out Invega sales but acknowledges they’ve been below expectations. Invega’s share of US antipsychotic scrips was only around 2 percent for the week ended May 9, according to Verispan. By comparison, Risperdal, which had 2007 sales of more than $4 billion, held a 21 percent market share.

Some insurers aren’t putting certain follow-on drugs on their lists of preferred drugs, or are requiring members to pay higher out-of-pocket costs than for other branded and generics. “It’s a marketing scheme that is not looking at improving healthcare, it’s looking at maintaining their revenues coming in,” Mirta Millares, manager of drug info services at Kaiser Permanente, tells Dow Jones.

The California health insurer that doesn’t include Invega on its list of preferred drugs. The active ingredient of Invega is derived from that of Risperdal, Millares noted, though it was different enough to get a new patent and regulatory approval.

Clinical studies supporting Invega’s approval primarily compared it with a placebo, but not Risperdal. In 2007, J&J released data showing Invega improved symptoms over AstraZeneca’s Seroquel, and J&J touts Invega’s long-acting formulation and once-daily dosing.

J&J says it’s not encouraging patients who are stable on Risperdal to switch to Invega, but had hoped for Invega to do well enough to make Risperdal’s patent protection next month less painful. “We need to do a better job at drawing a differentiation in a difficult-to-treat population, ” David Norton, J&J’s group chairman of pharmaceuticals, said earlier this month, according to Dow Jones.

A marketing campaign that might meet more success is underway at Shire, which last year began selling a new ADHD drug called Vyvanse. Shire’s top drug, Adderall XR for ADHD, will face generic competition beginning next year. So far, Vyvanse has captured about 7 percent of US ADHD scrips, according to Verispan, Dow Jones writes.

Although Shire recently said it expected 2008 Vyvanse sales to come in at the lower end of its forecast range of $350 million to $400 million, Shire ceo Matt Emmens tells Dow Jones he was confident that Vyvanse’s market share will eventually surpass Adderall XR’s peak market share of about 26 percent.

Emmens notes that Vyvanse is a different chemical entity than Adderall XR, and he thinks its pricing is attractive. “In a general nature, the market has become more price sensitive in the last 10 years,” he tells the newswire. Not incidentally, in the 1990s, Emmens headed the AstraZeneca partnership with Merck that marketed Prilosec and he was involved in the planning for Nexium’s marketing.

Meanwhile, Wyeth recently began selling its Pristiq, a new antidepressant chemically similar to its older Effexor XR, which is expected to face limited generic competition this year. Deutsche Bank’s Ryan thinks the odds of Pristiq’s success are slim because it appears to offer few benefits beyond those of Effexor, Dow Jones writes. Pristiq is priced, however, at a 20 percent discount.