Market Insider

After-hours buzz: Affiliated Managers to replace Forest Labs in the S&P 500

Getty Images

Check out which companies are making headlines after the bell Tuesday:

Affiliated Managers Group - The company is set to join the S&P 500, replacing Forest Laboratories. The change is expected to take place after the closing of trading on June 30.

Bristol-Myers Squibb - The company announced a study of a drug to treat a type of melanoma was stopped early because of evidence showing superior overall survival in patients receiving the drug, nivolumab, versus the control drug.

Vertex Pharmaceuticals - Shares continued to climb on news a combination of its drugs to treat cystic fibrosis improved lung function in a pair of late-stage clinical trials.

Walgreen - The drugstore chain fell in after-hours trade, continuing a drop that began after the drugstore chain reported disappointing quarterly results ahead of Tuesday's open.

Whole Foods Market - Shares of the specialty grocer gained after Morgan Stanley initiated coverage with an "overweight" rating.

—By CNBC's Kate Gibson.

Questions? Comments? Email us at