Major pharmaceutical producers threaten to lose $26.5 billion in annual sales this year, as 18 branded drugs are due to expire, analysts for investment bank Bernstein said in a recent note quoted widely by news agencies.

Bernstein analyst Tim Anderson has identified Roche, GlaxoSmithKline, Eli Lilly, Pfizer and AstraZeneca, among others, as being especially at risk. On the whole, he calculates that 2017’s potential patent expiry damage is is much more daunting than in 2015 and 2016, when respectively only four and nine drugs manufactured by companies in Bernstein’s coverage lost patent protection.

Patents due to expire this year are said to include Roche’s Rituxan, GSK’s Advair, Eli Lilly’s Humalog and Cialis, AstraZeneca’s Byetta, Pfizer’s Viagra and Merck’s Vytorin. Together, the 2017 patent losses and associated sales declines will continue to pressure growth in the industry under the investment bank’s scenario.

Some 45% of the sales identified as being at risk are for biologics, which will face biosimilar competition.  Bernstein expects Roche to to head the list of drugmakers facing biosimilar threats, followed by Sanofi, Bristol-Myers Squibb and Lilly.

In a look at potential patent losses through 2025 and including the potential value of pipeline assets, the analysis assumes that AstraZeneca will see the most growth of any drugmaker in the Bernstein portfolio, with gains averaging 5.6% per year, and that Pfizer will bring up the rear with only 2% annual growth.

Excluding pipeline assets, the analysts forecast that Bristol-Myers Squibb will see the most growth up to 2025. In a reverse of the first estimate, AstraZeneca is seen as trailing its peers.