Drugmakers, whose industry pricing faced renewed scorn this month from President Donald Trump, have been taking advantage of the U.S. tax overhaul he signed last year to buy back shares of their own underperforming stocks.

Large-cap biopharmaceutical companies took advantage of repatriation of overseas profits and lower corporate tax rates to push share repurchases to the highest level in at least 10 years. Companies led by Amgen and Pfizer bought back a combined $16.7 billion in the most recent quarter, according to data compiled by Bloomberg.

And they're not done. Celgene, whose market value has been cut in half over the course of about seven months, on Thursday boosted its repurchase capacity by $3 billion and planned a $2 billion accelerated buyback.

These biopharma leaders have so far confounded investor expectations for a big pickup in mergers and acquisitions, opting instead to help their earnings per share while taking advantage of their struggling stocks.

"There is pressure from investors to do something with their cash, and if there's not a great target to add assets to your pipeline, then a buyback will look more attractive," Credit Suisse analyst Vamil Divan said in a telephone interview. "A lot of these companies have limited growth outlooks in the near-term, so buybacks are a sure way to give yourself a bump if you don't want to take on risk just yet."

Congressional Republicans have argued that cutting taxes would spur an increase in investments by American companies and fuel innovation. Data compiled by Bloomberg on research by the top 20 drugmakers show that while R&D spending grew year-over-year in the first quarter, it remains below quarterly levels seen in the second half of 2017 and comparable to the fourth quarter of 2016.