13G Filing: Perceptive Advisors and La Jolla Pharmaceutical Co (LJPC)

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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 18, 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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