By Ben Hirschler
LONDON (Reuters) - A new wave of medicines that tap the power of the immune system to fight cancer could become the biggest drug class in history, with potential sales of $35 billion a year.
That bullish sales forecast by analysts at U.S. bank Citigroup highlights the growing excitement surrounding so-called immunotherapy after positive results from clinical trials conducted by companies such as Bristol-Myers Squibb and Roche Holding.
"We believe this market will generate sales of up to $35 billion (a year) over the next 10 years and be used in some way in the management of up to 60 percent of all cancers," Citi analyst Andrew Baum said on Wednesday.
Citi's forecast is considerably higher than current market consensus, but if it proves correct, then cancer immunotherapy would exceed the peak market value of top blockbuster drug classes such as statins for high cholesterol.
After years of puzzling over how to get the body's immune system to respond more effectively against tumor cells, scientists are now finding a number of promising avenues.
The new drugs are designed to target areas that act as brakes on the immune system. By interfering with these brakes, the drugs free the immune system to attack and kill cancer cells.
Bristol-Myers Squibb's nivolumab and Roche's MPDL3280A are two leading contenders in the field. Both had an impressive effect against a variety of cancers, according to preliminary trial results released last week.
Further details of the studies will be presented at a meeting of the American Society of Clinical Oncology in Chicago early next month.
Conventional chemotherapy and other cancer drugs often have a powerful effect in shrinking tumors, but the effect is typically short-lived. The effect of immunotherapy can last much longer because the immune system has effectively been reset to remember how to keep fighting cancer cells.
Citigroup said that immunotherapy has the potential to transform a significant percentage of cancers into something akin to a chronic disease, in a similar way to how HIV drugs have made the viral disease a manageable condition.
On the back of its upbeat prediction for the immunotherapy market, Citigroup has upgraded shares in Bristol-Myers Squibb and Roche to "buy" from "neutral".
Roche stock was trading 1.7 percent higher by 0914 GMT (5.14 a.m. EDT), outperforming a flat European drugs sector.
Other leading players with a range of drugs, vaccines and cell therapy treatments in the cancer immunotherapy field include GlaxoSmithKline, AstraZeneca, Novartis, Merck & Co and Amgen.
In addition to the progress being made in research, analysts believe that the immunotherapy field could also benefit from a new U.S. Food and Drug Administration initiative to speed approval of important and innovative drugs.
The U.S. watchdog recently started a scheme to allow quicker studies of life-saving therapies designated as a "breakthrough", provided that clinical data is compelling.
(Editing by David Goodman)