Early movers: MYL, HLF, CHTR, TMUS, UTX, SQ, KEY & more

Check out which companies are making headlines before the bell:

Mylan (MYL) — Mylan said it would launch an EpiPen generic at a 50 percent discount to the branded product's list price. The pharmaceutical firm has been under amid the rapid price increases for the EpiPen.

Herbalife (HLF) — Carl Icahn said late Friday he bought 2.3 million shares of Herbalife after Bill Ackman said he was approached indirectly by Icahn to buy the billionaire's stake in Herbalife.

Roche Holding (Swiss Exchange: ROG-CH) — The Swiss firm was granted Food and Drug Administration emergency use approval for its Zika test.

Charter Communications (CHTR) — Guggenheim resumed coverage of Charter's shares with a "buy" rating and a $300 price target, saying the firm's financial growth potential remains underappreciated. "We expect: 1) strong subscriber and revenue growth as the company takes market share, 2) margin improvement as operating efficiencies are realized, and 3) incremental investor interest, particularly if the company is added to the S&P500 index, to be the key share drivers over the next 12 months," Guggenheim said in a note.

Sanofi (Euronext Paris: SAN-FR), Regeneron (REGN) — The two firms jointly announced positive Phase 3 results for Praluent, a drug aimed at reducing cholesterol levels. Sanofi and Regeneron said in a statement Praulent reduced LDL cholesterol by about 50 percent during trials.

T-Mobile (TMUS) — Wells Fargo Securities upgraded the telecom company's stock to "outperform" from "market perform" as free cash flow should see a "significant ramp-up" next year. "This — more than any other metric — will likely become a key focus for investors as we move into late 2016 and 2017," Wells said.

United Technologies (UTX) — United Technologies reiterated its full-year guidance in an 8-K filing released Monday. The firm sees adjusted earnings per share in a range of $6.45 to $6.60 and sales between $57 billion and $58 billion.

Square (SQ) — BTIG downgraded the payments firm's stock to "neutral" from "buy" and removed its $12 price target, saying it sees the stock as more "fairly valued" after rising nearly 40 percent since June 27.

UnitedHealth (UNH), Humana (HUM), Aetna (AET)— A new study found that the pullback of health insurers from the Affordable Care Act marketplaces may create monopolies, according to The Wall Street Journal.

KeyCorp (KEY) — Piper Jaffray downgraded KeyCorp's stock to "neutral" from "overweight," citing concerns the firm may not meet Wall Street's earnings estimates for fiscal year 2017 and 2018. "Thus, we would expect the stock to have a difficult time outperforming peers as estimates continue to move lower over the next several months," Piper said.