WESTFIELD CAPITAL MANAGEMENT CO LP

Position in XENE — Xenon Pharmaceuticals Inc.

CIK 1177719 BOSTON, MA

Position in XENE

as of Jun 30, 2026 · filed Aug 12, 2026 Compact

Position Value

$90,980,265

+$9,484,029 QoQ

Shares Held

1,507,294

+7.5% QoQ

Ownership

1.56%

of shares outstanding

% of Portfolio

0.30%

of 13F equity value

Holder Rank

#16

of 314 holders

Holding Since

Dec 2023

11 quarters on record

Voting authority Sole 93% Shared 0% None 7%

Healthcare · as of Jun 30, 2026

WESTFIELD CAPITAL MANAGEMENT CO LP holds $3,083,455,798 across 23 Biotechnology names. XENE ranks #9 (3.0% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	ASND	Ascendis Pharma A/S	4,798,267	$1,279,793,774
2	RYTM	Rhythm Pharmaceuticals, Inc.	2,208,595	$245,220,302
3	ABVX	Abivax S.A.	1,309,825	$174,547,279
4	INSM	INSMED Inc	1,629,561	$173,743,793
5	PTCT	Ptc Therapeutics, Inc.	1,956,156	$159,563,644
6	PCVX	Vaxcyte, Inc.	2,472,428	$143,722,239
7	LEGN	Legend Biotech Corp	4,430,063	$127,940,219
8	RVMD	Revolution Medicines, Inc.	600,821	$112,521,756

11 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$90,980,265	1,507,294	+7.5%	Shares	Sole	2026-08-12
2026-03-31	$81,496,236	1,401,483	+14.2%	Shares	Sole	2026-05-11
2025-12-31	$54,983,876	1,226,771	+1.7%	Shares	Sole	2026-02-11
2025-09-30	$48,423,549	1,206,066	+4.6%	Shares	Sole	2025-11-12
2025-06-30	$36,076,536	1,152,605	-17.2%	Shares	Sole	2025-08-12
2025-03-31	$46,680,463	1,391,370	+20.2%	Shares	Sole	2025-05-09
2024-12-31	$45,361,808	1,157,189	+72.8%	Shares	Sole	2025-02-11
2024-09-30	$26,362,152	669,600	+4.0%	Shares	Sole	2024-11-12
2024-06-30	$25,091,858	643,546	+85.3%	Shares	Sole	2024-08-14
2024-03-31	$14,953,460	347,351	+46.3%	Shares	Sole	2024-05-10
2023-12-31	$10,939,019	237,495	—	Shares	Sole	2024-02-09
No filing history on record for this holder in this stock.