Protease Inhibitors

The first drug of a new class aimed at stopping HIV by inhibiting its protease enzyme came on the market last December--Hoffmann-La Roche's saquinavir. Between December and March, according to IMS America--a Dun & Bradstreet company that tracks sales of drugs primarily through U.S. drug stores and hospitals--saquinavir had already grossed $35 million in revenues. This explosive early growth may slow a bit, as saquinavir now meets competition from protease inhibitors made by Merck and Abbott, both of which won FDA approval in record time this March (see Protease Inhibitors: A Tale of Two Companies).

Many analysts have tried to assess where the protease market is headed. Their predictions are based on guesses about many variables: the number of people who will be infected with HIV, exhibit full-blown AIDS, seek treatment, or prefer one drug or a combination of drugs; how much they will pay for drugs; and whether they will develop drug resistance. Not surprisingly, the results are all over the map. "That really highlights the uncertainty in this marketplace," says Merck's vice president for anti-infectives, Bradley Sheares. Indeed, 3 years ago, no one would have predicted that combining AZT with 3TC would provide such a boost to their sales

One forecast, "The Protease Inhibitor Market," an 8 February report from San Francisco's Montgomery Securities, predicts that by the year 2000, 275,000 patients in the United States will be taking a mix of anti-HIV drugs. Montgomery also predicts that six protease inhibitors will be on the market then, each selling for $4000 a year, bringing in revenues of $755 million.

Another foresees a price drop, but larger total revenues. "Battling the HIV/AIDS Pandemic," issued on 23 August 1995 by Raymond James & Associates of St. Petersburg, Florida, predicts that in 2000, the annual per-patient cost of protease inhibitors will b e about $2000. While this report does not predict the number of users, it suggests that the total "potential market" in the United States will be $1.18 billion. Like many others, this report builds on flawed data--in this case, even failing to subtract from projections the number of patients likely to die. Another problem that throws estimates off is the assumption that clinicians will be treating AIDS patients as their colleagues on the front lines of research do, but that won't happen. HIV Insight, a longitudinal database marketed by IMS America to track treatment patterns, shows that combination therapy--all the buzz among researchers--has been slow to enter the clinic. For example, 84% of the people who started to take anti-HIV drugs last year began with monotherapy. Because all forecasts are plagued by such flaws, industry insiders take them with a grain of salt.