Insider · CIK 0002000389

Kastelein Johannes Jacob Pieter

Reports to the SEC for 1 company · NAARDEN

sec.gov

Transactions

Companies

Filings

CIK

0002000389

Forms 4 and 5

Insider transactions

36 trades

Date	Company	Role	Code	Shares	Price	Value	Shares after
2026-09-30	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+50.2K sh	—	—	119,548
2026-09-30	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−50.2K sh	$25.03	−$1.26M	69,302
2026-09-30	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−50.2K sh	—	—	344,983
2026-08-24	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+125K sh	—	—	194,302
2026-08-24	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−125K sh	$26.91	−$3.36M	69,302
2026-08-24	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−125K sh	—	—	395,229
2026-03-09	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+101K sh	—	—	170,711
2026-03-09	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−101K sh	$30.29	−$3.07M	69,302
2026-03-09	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−101K sh	—	—	520,229
2026-03-06	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+94.1K sh	—	—	163,426
2026-03-06	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−94.1K sh	$30.32	−$2.85M	69,302
2026-03-06	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−94.1K sh	—	—	621,638
2026-03-05	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+104K sh	—	—	173,769
2026-03-05	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−104K sh	$30.30	−$3.17M	69,302
2026-03-05	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−104K sh	—	—	715,762
2026-02-20	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−14.7K sh	$35.00	−$514K	84,289
2026-02-20	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−30.8K sh	$35.46	−$1.09M	53,500
2026-01-07	NAMSNewAmsterdam Pharma Co N.V.A Award	Director, Chief Scientific Officer	AAward	+25.5K sh	—	—	98,981
2026-01-07	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)A Award	Director, Chief Scientific Officer	AAward	+115K sh	—	—	115,000
2026-01-05	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−6,000 sh	$33.25	−$200K	73,481
2025-08-22	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−42.3K sh	$25.08	−$1.06M	76,960
2025-08-22	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−7,658 sh	$25.49	−$195K	69,302
2025-08-21	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−50K sh	$24.29	−$1.21M	119,302
2025-03-26	NAMSNewAmsterdam Pharma Co N.V.A Award	Director, Chief Scientific Officer	AAward	+19.3K sh	—	—	169,302
2025-03-26	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+45.5K sh	—	—	79,481
2025-03-26	NAMSNewAmsterdam Pharma Co N.V. · Restricted Stock UnitA Award	Director, Chief Scientific Officer	AAward	+45.5K sh	—	—	45,481
2025-03-26	NAMSNewAmsterdam Pharma Co N.V. · Restricted Stock UnitM Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−45.5K sh	—	—	0
2025-03-24	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+150K sh	—	—	150,000
2025-03-24	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−150K sh	—	—	820,229
2025-01-07	NAMSNewAmsterdam Pharma Co N.V.A Award	Director, Chief Scientific Officer	AAward	+34K sh	—	—	34,000
2025-01-02	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)A Award	Director, Chief Scientific Officer	AAward	+200K sh	—	—	200,000
2024-03-26	NAMSNewAmsterdam Pharma Co N.V.M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	+202K sh	—	—	201,673
2024-03-26	NAMSNewAmsterdam Pharma Co N.V.F Tax Payment	Director, Chief Scientific Officer	FTax Payment	−11.2K sh	$22.72	−$254K	190,476
2024-03-26	NAMSNewAmsterdam Pharma Co N.V.S Sale	Director, Chief Scientific Officer	SSale	−190K sh	$21.50	−$4.1M	0
2024-03-26	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)M Exercise/Conversion	Director, Chief Scientific Officer	MExercise/Conversion	−202K sh	—	—	970,229
2024-01-01	NAMSNewAmsterdam Pharma Co N.V. · Option (right to buy)A Award	Director, Chief Scientific Officer	AAward	+500K sh	—	—	500,000

Recent filings

Accepted (ET)
Oct 24
Kastelein Johannes Jacob Pieter0001193125-26-412431
SEC(opens sec.gov)
Aug 254
Kastelein Johannes Jacob Pieter0001193125-26-365202
SEC(opens sec.gov)
Mar 94
Kastelein Johannes Jacob Pieter0001193125-26-099073
SEC(opens sec.gov)
Feb 244
Kastelein Johannes Jacob Pieter0001193125-26-067260
SEC(opens sec.gov)
Jan 74
Kastelein Johannes Jacob Pieter0001193125-26-006662
SEC(opens sec.gov)

Companies

NewAmsterdam Pharma Co N.V.Director, Chief Scientific OfficerNAMS

Address

C/O NEWAMSTERDAM PHARMA COMPANY N.V. GOOIMEER 2-35

NAARDEN, 1411 DC