XENON PHARMACEUTICALS INC

Ticker: XENE CUSIP: 98420N105 Class: Common Stock

EcoR1 Capital, LLC's Holding History (CIK: 0001587114)

Note: Option positions (PUT/CALL) are excluded.

Q2 2015

Shares 73,000 Value ($000) $842 Avg Close $13.82 Range $11.43 - $17.50

Q1 2015

Shares 220,570 Value ($000) $3,720 Avg Close $18.47 Range $14.03 - $23.50

Q4 2014

Shares 328,070 Value ($000) $6,479 Avg Close $14.68 Range $9.21 - $21.95

Period	Shares	Value ($000)	Average Close	Price Range
Q2 2015	73,000	$842	$13.82	$11.43 - $17.50
Q1 2015	220,570	$3,720	$18.47	$14.03 - $23.50
Q4 2014	328,070	$6,479	$14.68	$9.21 - $21.95