Celldex Therapeutics Inc. Watch

from 10-K 2 pages Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from 10-K 1 page Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from 8-K 2 pages Indenture or similar

from 10-Q 2 pages Indenture or similar

from S-3 2 pages Indenture or similar

from S-3 2 pages Indenture or similar

from 10-K 1 page This Certifies That Is the Owner of Cusip Dated Countersigned and Registered: Computershare Trust Company, N.A. Transfer Agent and Registrar, Fully Paid and Non-Assessable Shares of the Common Stock, $0.001 Par Value Per Share, of Celldex Therapeutics, Inc. Transferable on the Books of the Corporation by the Holder Hereof in Person or by Duly Authorized Attorney, Upon Surrender of This Certificate Properly Endorsed. This Certificate Is Not Valid Unless Countersigned by the Transfer Agent and Registered by the Registrar. Witness the Facsimile Seal of the Corporation and the Facsimile Signatures of Its Duly Authorized Officers. Common Stock Par Value $0.001 Common Stock This Certificate Is Transferable in Canton, Ma, Jersey City, Nj and College Station, Tx See Reverse for Certain Definitions Certificate Number Shares . Incorporated Under the Laws of the State of Delaware President and Chief Executive Officer Senior Vice President and Chief Financial Officer by Authorized Signature 15117b 10 3 Zq|cert#|coy|cls|rgstry|acct#|transtype|run#|trans# Dd-MMM-Yyyy * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * ** Mr. Sample & Mrs. Sample & Mr. Sample & Mrs. Sample Zq00000000 Certificate Numbers 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 Total Transaction Num/No. 123456 Denom. 123456 Total 1234567 Mr a Sample Designation (If Any) Add 1 Add 2 Add 3 Add 4 Po Box 43004, Providence, Ri 02940-3004 Cusip Xxxxxx XX X Holder Id Xxxxxxxxxx Insurance Value 1,000,000.00 Number of Shares 123456 Dtc 12345678 123456789012345

from S-3 2 pages Zq|00000187|avan|c02|cus|c0000022632|capin|00453000|1051 Common Stock Par Value $0,001 Certificate Number Zq00000187 This Certifies That Is the Owner of Celldex Incorporated Under the Laws of the State of Delaware Therapeutics Computershare Shareholder Services Inc Specimen Certificate **One** Common Stock This Certificate Is Transferable in Canton, Ma and Jersey City, Nj Cusip 15117b 10 3 See Reverse for Certain Definitions Shares Fully Paid and Non-Assessable Shares of the Common Stock, $0.001 Par Value Per Share, of Celldex Therapeutics, Inc. Transferable on the Books of the Corporation by the Holder Hereof in Person or by Duly Authorized Attorney, Upon Surrender of This Certificate Properly Endorsed. This Certificate Is Not Valid Unless Countersigned by the Transfer Agent and Registered by the Registrar. Witness the Facsimile Seal of the Corporation and the Facsimile Signatures of Its Duly Authorized Officers. President and Chief Executive Officer Senior Vice President and Chief Financial Officer Dated 25-Mar-2010 Countersigned and Registered: Computershare Trust Company, N.A. Transfer Agent and Registrar. 229682 Specimen 1 1 1 1 1

from S-3 2 pages Zq|00000187|avan|c02|cus|c0000022632|capin|00453000|1051 Common Stock Par Value $0,001 Certificate Number Zq00000187 This Certifies That Is the Owner of Celldex Incorporated Under the Laws of the State of Delaware Therapeutics Computershare Shareholder Services Inc Specimen Certificate **One** Common Stock This Certificate Is Transferable in Canton, Ma and Jersey City, Nj Cusip 15117b 10 3 See Reverse for Certain Definitions Shares Fully Paid and Non-Assessable Shares of the Common Stock, $0.001 Par Value Per Share, of Celldex Therapeutics, Inc. Transferable on the Books of the Corporation by the Holder Hereof in Person or by Duly Authorized Attorney, Upon Surrender of This Certificate Properly Endorsed. This Certificate Is Not Valid Unless Countersigned by the Transfer Agent and Registered by the Registrar. Witness the Facsimile Seal of the Corporation and the Facsimile Signatures of Its Duly Authorized Officers. President and Chief Executive Officer Senior Vice President and Chief Financial Officer Dated 25-Mar-2010 Countersigned and Registered: Computershare Trust Company, N.A. Transfer Agent and Registrar. 229682 Specimen 1 1 1 1 1

from 10-K 97 pages Curagen Corporation as Issuer the Bank of New York, as Trustee Up to $120,000,000 Aggregate Principal Amount of 4.0% Convertible Subordinated Notes Due 2011 Indenture Dated as of February 17, 2004

from 8-K 4 pages This Second Supplemental Indenture, Dated as of December 31, 2009 (This “Second Supplemental Indenture”), Is by and Among Curagen Corporation (The “Curagen”), Celldex Therapeutics, Inc. (“Celldex”) and the Bank of New York Mellon (Formerly, the Bank of New York), as Trustee Under the Indenture Referred to Below (The “Trustee”)

from 8-K 8 pages This Supplemental Indenture, Dated as of September 30, 2009 (This “Supplemental Indenture”), Is by and Among Curagen Corporation (The “Company”), Celldex Therapeutics, Inc. (“Parent”) and the Bank of New York Mellon (Formerly, the Bank of New York), as Trustee Under the Indenture Referred to Below (The “Trustee”)

from 8-A12G 54 pages Avant Immunotherapeutics, Inc. and Equiserve Trust Company, N.A. as Rights Agent Shareholder Rights Agreement Dated as of November 5, 2004

from 8-K 54 pages Avant Immunotherapeutics, Inc. and Equiserve Trust Company, N.A. as Rights Agent Shareholder Rights Agreement Dated as of November 5, 2004

from 10-K 1 page Indenture or similar

from S-8 ~10 pages Indenture or similar

from 10-K ~50 pages Indenture or similar

from POS AM ~20 pages Common Stock Purchase Warrant Provisions

from S-8 ~20 pages Common Stock Purchase Warrant Provisions

from S-3 ~20 pages Stock Purchase Agreement