JOINT FILING AGREEMENT
Exhibit 1
Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended,
the undersigned hereby agrees, as of December 20, 2007, that only one statement containing the
information required by Schedule 13G, and each amendment thereto, need be filed with respect to the
ownership by each of the undersigned of shares of Common Stock of Neurocrine Biosciences, Inc., and
such statement to which this Joint Filing Agreement is attached as Exhibit 1 is filed on
behalf of each of the undersigned.
| RA CAPITAL BIOTECH FUND, L.P. | ||||||
| By: | /s/ Xxxxxxx X. Xxxxxxx | |||||
| Xxxxxxx X. Xxxxxxx | ||||||
| Manager | ||||||
| RA CAPITAL BIOTECH FUND II, L.P. | ||||||
| By: | /s/ Xxxxxxx X. Xxxxxxx | |||||
| Xxxxxxx X. Xxxxxxx | ||||||
| Manager | ||||||
| RA CAPITAL MANAGEMENT, LLC | ||||||
| By: | /s/ Xxxxxxx X. Xxxxxxx | |||||
| Xxxxxxx X. Xxxxxxx | ||||||
| Manager | ||||||
| XXXXXXX X. XXXXXXX | ||||||
| /s/ Xxxxxxx X. Xxxxxxx | ||||||
| XXXXX XXXXXXXXXX | ||||||
| /s/ Xxxxx Kolcinsky | ||||||
