Millennium Pharmaceuticals says it expects US sales of its cancer drug Velcade to climb by 20%-30% in 2008, but analysts are saying that the firm is erring on the side of caution.

The Cambridge, Massachusetts-based firm made the forecast while revealing details of what chief executive Deborah Dunshire described as the most successful year in Millennium’s 15-year history. Velcade (bortezomib), which is currently indicated for the treatment of patients with multiple myeloma and mantle cell lymphoma who have received at least one prior therapy, is partnered with Johnson & Johnson but Millennium sells the drug in the USA and 2007 turnover from the treatment there was up 20% to $265 million.

Now the company says that this could rise to $320-$345 million for 2008, while royalties should be in the region of $175-$185 million. The group’s net income should be between $10-$25 million.

Millennium shares have been on the rise of late but this announcement disappointed the investment community who noted that fourth–quarter sales of Velcade were impressive and had hoped for a more enthusiastic forecast. Leerink Swann analyst Howard Liang had predicted in a research note just before the announcement that sales of Velcade will hit $379 million in 2008, especially as the US Food and Drug Administration is expected to back the drug later this year as a first-line treatment for patients with multiple myeloma.

In December, Millennium presented positive data from two late-stage trials evaluating combinations of Velcade to support its supplemental filing and they suggested that the drug could gain a greater market share than Celgene's rival product Revlimid (lenalidomide).