Bristol-Myers Squibb Co. BMY -0.83% and partner Ono Pharmaceutical Co. 4528.TO -0.43% have sued Merck & Co. MRK -0.92% , alleging that its new cancer drug violates their patent for a method of harnessing the body’s immune system to fight cancer.
Bristol and Ono filed suit in federal court in Delaware on Thursday, the same day that Merck received U.S. Food and Drug Administrationapproval to market Keytruda as a treatment for the deadly skin cancer melanoma.
The dispute represents another front in a multicompany battle in the emerging market for so-called immunotherapy cancer drugs, which some analysts predict will reach more than $30 billion in annual sales in the next decade. The drugs have generated promising results in clinical trials, particularly for melanoma but also for other types of cancer.
Keytruda, the generic name of which is pembrolizumab, works by blocking a component of immune-system cells known as programmed death receptor 1. The mechanism helps take a brake off the immune system, enhancing its ability to destroy cancer cells with what doctors say are manageable side effects.
Bristol and Ono have developed a competing PD-1 blocker known as nivolumab. The drug went on sale in Japan last week under the brand Opdivo for melanoma. Bristol has said it expects to file by Sept. 30 for FDA approval of nivolumab as a melanoma treatment, and by year-end to complete an application for FDA clearance of nivolumab to treat a form of lung cancer.
Bristol and Ono’s lawsuit says Merck’s Keytruda infringes a U.S. patent that was issued to Ono in May on methods of treating cancer with an anti-PD-1 compound. Bristol has an exclusive license to Ono’s patent.
Bristol and Ono allege that Merck started developing pembrolizumab after the partners created nivolumab and that Merck has been aware of their U.S. patent.
“Merck is threatening to exploit that invention with a later-developed anti-PD-1 antibody,” the lawsuit says. The plaintiffs ask the court to declare that Merck infringes the patent and to award damages to compensate Bristol and Ono for the infringement.
Merck said the lawsuit was without merit and that the company was confident it wouldn’t be prevented from marketing pembrolizumab. Similar patent litigation among the companies is under way in Europe. Merck said in an August filing to the U.S. Securities and Exchange Commission that the Ono patent was invalid.
The stakes are high. Merck is selling its drug for about $12,500 a month per patient in the U.S., or $150,000 for a full year of treatment. Ono’s drug in Japan costs about $143,000 a patient for a full year. The cost of the drugs vary with patient weight and treatment duration.
Credit Suisse has estimated that Bristol and Ono eventually could generate significant royalties paid by competitors as a result of a broad set of patents on PD-1-targeting drugs.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.