LONDON (Reuters) - Immunotherapy, which boosts the immune system to fight cancer, could be the next big opportunity for Genmab, potentially driving peak sales of its top-selling drug well past $10 billion a year, its chief executive believes.
Shares in the Danish firm have surged 4,000 percent in the past five years as it has morphed from a cash-burning biotech into a profitable business, on the back of hopes for Darzalex, and Jan van de Winkel says the story is far from over.
"The thing I'm excited about is the recent data that shows Darzalex is not only good at killing cancer but it also knocks out the suppressor cells of the immune system," he said in an interview during a visit to London.
"It could be a novel way of accelerating anti-tumor immunity in a much broader population."
Currently approved to treat multiple myeloma, a cancer of cells found in the bone marrow, Darzalex is marketed by Johnson & Johnson and has got off to a flying start since its approval last November. Genmab receives tiered royalties of between 12 and 20 percent from J&J on its sales.
Van de Winkel said he was "very comfortable" with current analyst forecasts for annual sales of the drug reaching a peak $9 billion but added this did not include the possibility it might also be used in a much wider range of cancers.
The medicine, which is given by infusion, is now being tested in multiple myeloma in combination with three immunotherapies -- Roche's Tecentriq, Bristol-Myers Squibb's Opdivo and durvalumab, from AstraZeneca and Celgene.
Significantly, it is also being investigated in solid tumor with a trial combining it with Tecentriq due to begin "within weeks". Van de Winkel declined to say which cancer was involved, but Roche's immunotherapy drug is currently approved for bladder cancer and a lung cancer decision is imminent.
Just how well Darzalex works alongside such so-called checkpoint inhibitors will not become clear until at least the end of 2017, since a key focus of clinical trials will be the durability of response.
Checkpoint inhibitors, which help the immune system to recognize and fight cancer, are the hottest new drug class to have emerged in oncology for years and adding Darzalex to the mix would clearly extend Genmab's market.
"It could represent a very dramatic expansion beyond $9 billion of forecast peak sales," Van de Winkel said. "It's a guess at this moment but it could definitely be double-digit billions per year, if it works."
With a market capitalization of $10 billion, 17-year-old Genmab is Europe's second-biggest biotech company behind Actelion, although both still lag well behind U.S. groups like Gilead, Amgen and Celgene.
Van de Winkel aims to take Genmab to the next level by using the "cash machine" of Darzalex royalties to fund research into a new wave of early-stage cancer drugs in which it will retain majority control.
"My strategy is to select the next clear winner in the next three to four years and hold on to 50 percent or more," he said.
Editing by Elaine Hardcastle