Stocks making the biggest moves after hours: Tailored Brands, Mylan and more

Heather Bresch, CEO of Mylan.
Adam Jeffery | CNBC
Heather Bresch, CEO of Mylan.

Check out the companies making headlines after the bell on Wednesday:

Shares of Tailored Brands plummeted nearly 20 percent after the bell, despite reporting first-quarter earnings and revenue that beat analysts' expectations. The retail holding company reported earnings per share of 50 cents on revenue of $818 million, beating analysts' estimates of 48 cents a share on $794 million in revenue. Tailored Brands missed on comparable-store sales, however, reporting 2.1 percent same-store sales, falling short of the 2.5 percent analysts had expected. Tailor Brands, which owns brands like Men's Wearhouse and Jos. A Bank, also reduced its debt by $110 million in the first quarter.

Shares of Mylan fell more than 4 percent in the extended session. The Pennsylvania pharmaceutical company announced that U.S. health regulators were unable to approve its generic version of the asthma medication Advair, citing "minor deficiencies" with the drug. Mylan did not clarify whether it would be able to resolve the issues and snag an approval this year.

Shares of GlaxoSmithKline, which produces name-brand Advair, climbed 2.2 percent after the announcement, before paring its gains.

Comcast whipsawed in extended trading, before trading up less than 1 percent. The tech and media giant announced a $65 billion bid for Twenty-First Century Fox units that are currently in an agreement to be acquired by Disney. The bid, announced Wednesday, represents a 19 percent premium to Disney's offer. Disney stock edged up slightly after the announcement.

Disclosure: Comcast is the parent company of NBCUniversal and CNBC.

--Thomson Reuters contributed to this report.

CORRECTION: This story has been updated to correct the spelling of Tailored Brands and Jos. A Bank. Also, it has been updated to show Tailored Brands reported earnings per share of 50 cents on revenue of $818 million, beating analysts' estimates of 48 cents a share on $794 million in revenue.