Public biotech companies in the United States took advantage of what some people call a biotech bull market to raise more than $1.2 billion in equity and debt. Globally, public life sciences companies raised more than $5 billion during the third week of the new year, with Pfizer accounting for $3.65 billion of that amount in a four part bond issue as it tested the public market’s interest in its soon-to-be-public animal health unit Zoetis.

Demand for the Pfizer debt offering was so strong that just one day later the Big Pharma set the terms for Zoetis’ IPO with plans to raise $2 billion through an offer of 86.1 million shares at $22 to $25 a share.

Onyx Pharmaceuticals took advantage of a strong share price, up 134 percent from its 52-week low, to raise $358.6 million in the biggest biotech follow-on offering of the week. The cancer drug developer priced 4.4 million shares at $81.50 a share, a $2 discount to its trading price when the offer was announced. Onyx markets two cancer drugs: Kyprolis to treat multiple myeloma in patients who have failed two previous therapies, and Nexavar to treat liver cancer and advanced kidney cancer with partner Bayer. Onyx shares fell 5 percent after the offering and were down 7.4 percent for the week.

Alnylam Pharmaceuticals also took advantage of its strong share price, up 116 percent from its 52-week low, to raise $185.2 million. The developer of therapeutics based on RNA interference priced its shares at $20.13 a share, just below its trading price at the time of the offering. Alnylam will start late-stage trials of its lead compound to treat the rare condition transthyretin-mediated amyloidosis with familial amyloidotic polyneuropathy. The stock jumped 7.7 percent after the offering and Alnylam ended the week up 10.2 percent.

InterMune raised $133.7 million in a follow-on offering and another $105 million through the sale of 2.5 percent convertible senior notes due in 2017. The company markets Esbriet in the European Union to treat idiopathic pulmonary fibrosis. Shares in the follow-on offering were priced at $9.90, just below the trading price at the time of the pricing. Although shares rose 3.9 percent following the offering, they ended the week flat.

Specialty pharmaceutical Pacira raised $110 million through a private offering of 3.25 percent convertible senior notes due in 2019. The company will use most of the money to support the commercialization of Exparel, which was launched in the United States in April 2012 to treat post-operative pain. Pacira’s shares rose 2.5 percent after the offering and ended the week up 7.9 percent.