Subsequent Events	9 Months Ended
Sep. 30, 2014
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Events Equity Offering In October 2014, we completed an underwritten public offering of 6,200,000 shares of our common stock at a public offering price of $26.00 per share. In addition, the underwriters of the offering exercised their over-allotment option to purchase an additional 930,000 shares from us at the public offering price of $26.00. The net proceeds from the offering to us including the over-allotment option, net of underwriting discounts and commissions and offering expenses of approximately $10.7 million, were approximately $174.7 million. Manufacturing Supply Agreement In October 2014, we entered into an agreement with Lonza Sales AG (“Lonza”), pursuant to which Lonza, a contract manufacturing organization, will manufacture clinical and commercial supply of Andexanet alfa and perform pre-validation and validation work on our behalf. Under the agreement, we are required to purchase at least seven commercial batches of Andexanet alfa per year from Lonza, over a period of five years following first regulatory approval of the product from Lonza’s facility. We may cancel these orders upon written notice to Lonza, in which case, we will be obligated to pay a cancellation fee ranging from between €10.0 million (or $12.7 million based on the exchange rate as of September 30, 2014) and €13.3 million (or $16.9 million based on the exchange rate as of September 30, 2014), depending on the time of cancellation and any applicable costs related to raw materials and certain pass-through costs. The term of the agreement will end on the fifth anniversary of the date of the first regulatory approval and may be early terminated by either party for the other party’s uncured material breach or insolvency or, prior to the first regulatory approval for any reason on not less than twelve months prior written notice. In addition, we may also terminate the agreement if we discontinue the development or commercialization of Andexanet alfa for regulatory, safety, efficacy or other commercial reasons and for technical reasons after delivery of the first engineering batch but before delivery of the second engineering batch. In such circumstance we will be obligated to pay a termination payment ranging from between €10.0 million (or $12.7 million based on the exchange rate as of September 30, 2014) and €15.0 million (or $19.0 million based on the exchange rate as of September 30, 2014), depending on the time of termination, which includes the cancellation fee, and any applicable costs related to raw materials. In November 2014, we made an upfront payment to Lonza in the amount of €1.2 million (or $1.5 million based on the exchange rate used on the date of payment) and will be required to make additional milestone payments of €2.5 million (or $3.2 million based on the exchange rate as of September 30, 2014) upon Lonza’s achievement of certain regulatory events.

11. Subsequent Events

Equity Offering

In October 2014, we completed an underwritten public offering of 6,200,000 shares of our common stock at a public offering price of $26.00 per share. In addition, the underwriters of the offering exercised their over-allotment option to purchase an additional 930,000 shares from us at the public offering price of $26.00. The net proceeds from the offering to us including the over-allotment option, net of underwriting discounts and commissions and offering expenses of approximately $10.7 million, were approximately $174.7 million.

Manufacturing Supply Agreement

In October 2014, we entered into an agreement with Lonza Sales AG (“Lonza”), pursuant to which Lonza, a contract manufacturing organization, will manufacture clinical and commercial supply of Andexanet alfa and perform pre-validation and validation work on our behalf.

Under the agreement, we are required to purchase at least seven commercial batches of Andexanet alfa per year from Lonza, over a period of five years following first regulatory approval of the product from Lonza’s facility. We may cancel these orders upon written notice to Lonza, in which case, we will be obligated to pay a cancellation fee ranging from between €10.0 million (or $12.7 million based on the exchange rate as of September 30, 2014) and €13.3 million (or $16.9 million based on the exchange rate as of September 30, 2014), depending on the time of cancellation and any applicable costs related to raw materials and certain pass-through costs.

The term of the agreement will end on the fifth anniversary of the date of the first regulatory approval and may be early terminated by either party for the other party’s uncured material breach or insolvency or, prior to the first regulatory approval for any reason on not less than twelve months prior written notice.

In addition, we may also terminate the agreement if we discontinue the development or commercialization of Andexanet alfa for regulatory, safety, efficacy or other commercial reasons and for technical reasons after delivery of the first engineering batch but before delivery of the second engineering batch. In such circumstance we will be obligated to pay a termination payment ranging from between €10.0 million (or $12.7 million based on the exchange rate as of September 30, 2014) and €15.0 million (or $19.0 million based on the exchange rate as of September 30, 2014), depending on the time of termination, which includes the cancellation fee, and any applicable costs related to raw materials.

In November 2014, we made an upfront payment to Lonza in the amount of €1.2 million (or $1.5 million based on the exchange rate used on the date of payment) and will be required to make additional milestone payments of €2.5 million (or $3.2 million based on the exchange rate as of September 30, 2014) upon Lonza’s achievement of certain regulatory events.