Last week, we wrote that a coalition of AIDS groups worried about the cost of Isentress, a novel HIV med that’s expected to be approved by the FDA this month, is orchestrating an Internet protest asking the drugmaker to “set a price that offers a reasonable profit without worsening the economic problems faced by patients and payers.” In talks with those activists, Merck apparently indicated it would price Isentress in line with similar meds, which raised red flags

What do some other AIDS meds cost? This morning, The Wall Street Journal (subscription required) follows up and notes that Pfizer Selzentry, which won FDA approval this summer, costs about $10,600 a year wholesale. Roche’s Fuzeon, which came out in 2003, costs about $24,500 a year wholesale. And two relatively new AIDS drugs, such as Johnson & Johnsons’ Prezista and Bristol-Myers Squibb’s Reyataz, both cost around $9,500 a year wholesale,

Merck declines to discuss pricing ahead of an FDA decision. But if the company were to price Isentress at the high end of the range, “there’s no way the system could handle that,” Lanny Cross, a former director of the New York AIDS Drug Assistance Program and a consultant for the National Alliance of State and Territorial AIDS Directors, tells the Journal.

Martin Delaney, a longtime AIDS activist, who has participated in talks with Merck on behalf of the Fair Pricing Coalition, which initiated the Internet petition, says the drugmaker has shown sensitivity to patient financial needs in the past. But he says Merck officials are “arguing they need to get profitability.” He notes that Merck hasn’t been shy about saying $2 billion was spent on HIV research.

Merck may find it difficult to sell Isentress at the highest price possible when many public-assistance programs that help pay for HIV treatments are experiencing fiscal strain, the Journal writes. In the 2006 fiscal year, 20 out of nearly 60 AIDS Drug Assistance Programs saw their budgets decrease, according to the Kaiser Family Foundation, a nonprofit health-policy research group. Such programs bought drugs for nearly 100,000 HIV patients in 2006 and provided insurance coverage for thousands more, according to Kaiser.

Merck declines to specify how much it spent to develop Isentress or to research other HIV drugs, beyond saying it has spent “hundreds of millions of dollars” on such work. “We believe (HIV research) is the right thing to do,” Robin Isaacs, Merck’s executive director of infectious-disease clinical research, tells the Journal. “We are hopeful that will translate into return on investment for our shareholders.”

While Merck is viewed by many in the AIDS community as one of the major drug makers most committed to HIV research, revenue from such products currently represents a modicum of Merck’s total revenue, which amounted to $22.64 billion last year, the Journal points out. The drugmaker drew a combined $327 million from sales of Crixivan, an HIV drug from the mid-1990s that is no longer used widely, and Stocrin, which Merck sells overseas.

Isentress could provide a bottom-line boost, though it doesn’t carry the potential of some major Merck products such as asthma-drug Singulair, which had $3.58 billion of sales last year, the Journal reminds us. Credit Suisse drug analyst Catherine Arnold estimates Merck’s annual sales of Isentress could be $500 million world-wide by 2012, and likely more if used in a broad swath of patients. Merck is an investment-banking client of Credit Suisse.

Another factor influencing Isentress’s prospects is whether docs will prescribe it for patients in early stages of HIV treatment. The FDA advisory panel debated how early in a patient’s treatment to approve Isentress use, given that most patients in Merck’s trials had used a number of drugs already. It will be up to the FDA to make that determination, though docs would be permitted to prescribe Isentress “off label” at any point in treatment.

About two-dozen HIV drugs are now available, most of which block two enzymes that HIV uses to replicate in the body: protease and reverse transcriptase. Isentress, known generically as raltegravir, would be the first drug on the market to target a third enzyme — integrase — that helps the virus insert its DNA into that of human cells. Because HIV mutates quickly to outwit drugs, cocktails of three medications are typically used to simultaneously attack the virus in different spots. Patients tend to change drugs as their virus adapts. Isentress would be taken along with other drugs.

Merck’s late-stage studies of Isentress involved patients who had been receiving HIV treatment for a median of 10 years, had virus resistant to at least one drug in each of three major classes of HIV drugs and showed evidence the virus was continuing to replicate in their bodies. In other words, they were already sick or in danger of becoming sick soon.

“Since this drug seems to be very effective and pretty well tolerated, I think (there is) potential for it to move in and take territory” from some older drugs, Judith Feinberg, a leader of the AIDS clinical-trials unit at the University of Cincinnati College of Medicine who served on the advisory panel, tells the Journal.

However, she says some docs may be uncomfortable prescribing Isentress more broadly until further studies are complete. Merck is currently conducting late-stage Isentress studies in patients who are new to HIV treatment. The company expects to have the results toward the end of 2008. Feinberg says she had no ties to Merck at the time of the panel hearing but has since agreed to give talks sponsored by the company.

Isentress will be used principally in “patients who have tried a whole raft of drugs,” Daniel Kuritzkes, director of AIDS research at Brigham and Women’s Hospital in Boston, who consults for Merck and other HIV-drug makers, tells the paper. However, “for patients who have earlier stages of disease, there will be some tendency to hold off because it’s so useful in patients with extensive treatment experience.”

Another potential complication is that Isentress is taken twice a day, while some new patients take a once-a-day pill called Atripla that combines three drugs. That could make it tougher to get patients to take Isentress from the beginning.

While Merck has little else for HIV in clinical trials, research-and-development chief Peter Kim says the company is committed to pursuing HIV treatments, and continues to do research related to the integrase enzyme. “We really do think that this drug-resistance issue is going to continue to be a significant unmet medical need,” Kim tells the Journal.