13G Filing: Perceptive Advisors and Albireo Pharma Inc. (ALBO)

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EXHIBIT 1

AGREEMENT

The persons below hereby agree that
the Schedule 13G to which this agreement is attached as an exhibit, as well as all future amendments to such Schedule 13G, shall be filed on behalf of each of them. This agreement is intended to satisfy the requirements of Rule 13d-1(k)(1)(iii)
under the Securities Exchange Act of 1934.

Date: December 4, 2017
PERCEPTIVE ADVISORS LLC
By:

/s/ Joseph Edelman

Name:  Joseph Edelman

Title:    Managing Member

/s/ Joseph Edelman

JOSEPH EDELMAN
PERCEPTIVE LIFE SCIENCES MASTER FUND, LTD.
By: Perceptive Advisors LLC
By:

/s/ Joseph Edelman

Name:  Joseph Edelman

Title:    Managing Member

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