X0202 4 2005-03-05 0 0001018952 KOS PHARMACEUTICALS INC KOSP 0001248149 JAHARIS MICHAEL 1 0 1 0 Common Stock, $.01 Par Value 2005-03-05 5 G 0 E 42036 0 A 378140 I By Spouse Common Stock, $.01 Par Value 5311651 D Common Stock, $.01 Par Value 2000000 I By Jaharis Holdings, LLC Common Stock, $.01 Par Value 7610000 I See Footnote 4. Common Stock, $.01 Par Value 960069 I See Footnore 5. Includes one share held jointly with Michael Jaharis' spouse. Gift from a GRAT. These shares are owned directly by Jaharis Holdings, LLC ("Jaharis Holdings"), a ten percent owner of the Issuer. Michael Jaharis disclaims beneficial ownership of all securities held or beneficially owned, directly or indirectly, by Jaharis Holdings for purposes of Section 16, except to the extent of his pecuniary interest therein, and this report should not be deemed an admission that Michael Jaharis is the beneficial owner of all of such securities for purposes of Section 16. Michael Jaharis is the indirect controlling shareholder of the corporation that owns such securities. Michael Jaharis is the controlling shareholder of the corporation that owns such securities. Lawrence B. Copperman, Attorney-in-fact 2005-03-16