11. Herceptin

Herceptin

Product: Herceptin
Generic name: trastuzumab
Company: Roche
2015 sales: $6.79 billion
2022 sales: $3.98 billion
Current indications: breast cancer; gastric cancer

Approximately 15% to 20% of all breast cancer patients have tumors that are HER2-positive, which tend to grow more quickly than those that are HER2-negative. Until 1998, the prospects for patients with this form of cancer were pretty bleak, but the launch of Roche's Herceptin in that year revolutionized the way these patients were treated. The drug was Roche's first targeted cancer drug, and it has dominated the HER2-positive market ever since, with market share still well above 90%.

But Herceptin's position at the top of the HER2 tree is under threat from biosimilars, as the main EU patent for the drug was lost in 2014 and is due to expire in the U.S. in 2019. Mylan and Biocon have already launched a biosimilar version of the drug as Canmab in India, while Celltrion has another on the market in South Korea as Herzuma. Meanwhile, Mylan and Biocon are also squaring up for a launch in the EU, along with Samsung Bioepis, which has filed for approval of its SB3 candidate.

Analysts at Sanford Bernstein have suggested that Mylan/Biocon's version could be on the market by 2017 in Europe and in the U.S. the following year, a view shared by Roche's chief operating officer for pharmaceuticals, Daniel O'Day. "At this stage the main exposure for our business would certainly be more in 2018 than 2017," he said during the company's second-quarter conference call in 2016. "I feel quite confident that [the HER2 franchise] will grow through the biosimilar erosion curve of Herceptin."

Once the patent matters are out of the way, no shortage of players will be queuing up for a slice of the opportunity. Amgen/Allergan and Pfizer are among the other companies with biosims in late-stage testing.

11. Herceptin