HIV Market: Reyataz Races To 10% Market Share, Fuzeon Building Steadily

Bristol-Myers Squibb's Reyataz (atazanavir) has captured 10% of the protease inhibitor market after just two weeks, the company reported July 24.

Reyataz is "off to a fast start" following FDA approval June 20, Bristol Exec VP Donald Hayden told the company's quarterly earnings call.

Reyataz was launched in July after the close of the second quarter, so the company did not report initial sales figures (¹ (Also see "Bristol Reyataz To Launch In July; Lipid Data Included In Labeling" - Pink Sheet, 23 Jun, 2003.), p. 27).

Hayden acknowledged that the Reyataz launch was helped by some of the dynamics of the HIV market, including the "pent-up demand" among patients already on other protease inhibitors who were awaiting the introduction of a new product.

However, Hayden added, the early script data does not yet include any patients transferred from Bristol's expanded access program for the drug, so there should be another bump in market share in coming weeks.

Another new entrant in the HIV category, Roche/Trimeris' Fuzeon (enfuvirtide), is building more slowly, in keeping with the product's status as the first in a new category (fusion inhibitors) and its high price tag.

Fuzeon was approved by FDA in March and launched in April (² (Also see "Roche Fuzeon Approval Presents Challenges Of Reimbursement, Supply" - Pink Sheet, 17 Mar, 2003.), p. 3).

The product generated just over $5 mil. in sales (CHF 7 mil.) during the first two months on the market, Roche reported July 23.

Because Fuzeon is distributed direct to patients by Chronimed, the early sales totals do not include any inventory building, Roche noted.

Roche Global Pharmaceuticals Head William Burns told a securities analysts meeting in New York July 24 that there are currently 2,250 patients on Fuzeon in the U.S., with a similar number working their way through the enrollment and reimbursement process managed by Chronimed.

While most government and private insurers are covering the product, Burns noted that some patients have difficulty with the copayment required on the $20,000 per year product.

Roche expects to add about 1,000 patients a month to therapy, Burns said.

"Supply is not an issue," he added. "We would have enough for on the order of 18,000 patients coming through this year," Burns said.

At $20,000 per patient per year, that would suggest the ability for Fuzeon to reach $360 mil. in annual sales with the current capacity. Burns emphasized that, given the rate of enrollment, it will be a "gradual stepwise build" towards that amount.

Roche estimates that within "a couple of years" Fuzeon capacity will expand to levels sufficient for up to 40,000 patients ($800 mil. per year).

Roche and Trimeris are investing in new production capacity in Boulder, Colo. as the next step in building supplies of the product.

The plan will be to create a "flexible" production facility to manufacture both Fuzeon and Trimeris' next developmental fusion inhibitor, T-1249. The new production line will give the companies the capacity to supply up to six tons of either drug.

Burns explained that the companies have decided to "concentrate on chemical manufacturing rather comparable to the approach we have today, rather than using an alternative of biological" production process for T-1249.

"It could take us longer" to ramp up biological production, Burns said, and that approach would eliminate the flexibility of devoting the new capacity to either molecule.

"It is not that we actually anticipate that one cannibalizes the other," Burns added. "T-1249 right now has a very clear role in patients who could become resistant to Fuzeon, so it would be sequential use of the drugs as fusion inhibitors."

T-1249 is currently in Phase II testing. Roche noted that one aspect of the development program for the follow-on agent has involved awaiting data on HIV mutations in response to Fuzeon.