(Bloomberg) -- The disruptive impact on stock markets of Novo Nordisk A/S’s diabetes drugs is getting ever wider. 

The Danish company, now Europe’s largest by market value, said late Tuesday it was halting a study which looked at the impact of its blockbuster Ozempic drug on kidney failure after it showed effectiveness surprisingly early.

The news hit shares of the world’s biggest kidney dialysis providers. Fresenius Medical Care AG & Co. plunged as much as 24% in Frankfurt, while other kidney-related stocks including DaVita Inc. and Baxter International Inc. — which touched an eight-year low — tumbled in US trading Wednesday. Shares of Outset Medical Inc. are trading at the lowest since the dialysis-machine maker’s 2020 debut. 

The trial halt was recommended by an independent data monitoring committee after an interim analysis met preset criteria for efficacy. Full results are expected in the first half of next year, the Danish drugmaker said. 

Novo’s Ozempic and Wegovy injectable drugs, a class of medicines known as GLP-1s, have been causing ripple effects across the stock market, for the makers of everything from snacks to booze. Last week, Walmart Inc. said it’s seeing an impact on demand from people taking Ozempic, Wegovy and other appetite-suppressing medications. That weighed on shares of other food and beverage companies.

Read more: Ozempic Threat Is Spurring a Slump in Snack and Beer Stocks

“The body of evidence to support GLP-1 use, over and above weight loss and blood glucose control, continues to grow,” Citigroup Inc. analyst Peter Verdult wrote in a note, referring to Novo’s study.

As investors bet that this new class of weight-loss drugs will improve the overall health of millions of Americans, US health care stocks have underperformed the S&P 500 Index this year. Medical-device makers like Dexcom Inc. and Insulet Corp. have performed particularly poorly, down 30% and 54%, respectively.

But some stocks have been gaining along with Novo, which is up 45% year-to-date. Eli Lilly & Co., whose pipeline of drugs to treat obesity includes Mounjaro, is now the world’s biggest health-care company by market value. And shares in WW International Inc. — better known as Weight Watchers — have more than tripled this year. WW bought a telemedicine firm that prescribes obesity medications earlier this year.

--With assistance from Angel Adegbesan.

(Updates pricing throughout. An earlier version of this story corrected the chart to remove reference to diabetes stocks.)

©2023 Bloomberg L.P.