KEY POINTS
  • UBS slashes Pfizer's rating to neutral from buy, citing the so-called "patent cliff" in the coming years that would greatly offset the revenue growth.
  • BMO downgrades Merck to market perform from outperform, saying Wall Street's expectations for the drugmaker are too high given its over-dependence on the drug Keytruda.
A man walks past Pfizer's world headquarters in New York.

Shares of Pfizer and Merck fell on Wednesday after Wall Street analysts downgraded the drugmakers on increased competition and the pending loss of patent protection.

UBS slashed Pfizer's rating to neutral from buy on Wednesday, citing the so-called "patent cliff" in the coming years on key products that would greatly offset revenue growth. The bank also cut its 12-month price target for Pfizer to $46 from $48.5.