Form of 2.125% Senior Note due 2018 GLOBAL SECURITY

Exhibit 4.2

Form of 2.125% Senior Note due 2018

GLOBAL SECURITY

THIS NOTE IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITARY OR A NOMINEE OF THE DEPOSITARY. THIS NOTE IS EXCHANGEABLE FOR NOTES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY, BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH A SUCCESSOR DEPOSITARY. TRANSFERS OF PORTIONS OF THIS GLOBAL SECURITY ARE LIMITED TO TRANSFERS PERMITTED BY THE INDENTURE.

CELGENE CORPORATION

2.125% Senior Note due 2018

CUSIP: 151020 AT1

ISIN: US151020AT12

Celgene Corporation, a Delaware corporation (herein called the “Company,” which term includes any successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum set forth in the attached Schedule of Increases and Decreases in Global Note on August 15, 2018 (the “Maturity Date”) (except to the extent redeemed or repaid prior to the Maturity Date) and to pay interest thereon from August 12, 2015 (the “Original Issue Date”) or from the most recent Interest Payment Date to which interest has been paid or duly provided for semi-annually at the rate of 2.125% per annum, on February 15 and August 15 (each such date, an “Interest Payment Date”), commencing February 15, 2016, until the principal hereof is paid or made available for payment.

Payment of Interest. The interest so payable, and punctually paid or made available for payment, on any Interest Payment Date, will, as provided in the Indenture, be paid, in immediately available funds, to the Person in whose name this Note is registered at the close of business on the February 1 or August 1 (whether or not a Business Day, as defined in the Indenture) as the case may be, next preceding such Interest Payment Date (the “Regular Record Date”). Any such interest not punctually paid or duly provided for (“Defaulted Interest”) will forthwith cease to be payable to the Holder on such Regular Record Date, and such Defaulted Interest may be paid to the Person in whose name this Note is registered at the close of business on a special record date (the “Special Record Date”) for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Notes not less than ten days prior to such Special Record Date, or may be paid at any time in any other lawful manner not inconsistent with requirements of any securities exchange on which the Notes may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture.

Place of Payment. Payment of principal, premium, if any, and interest on this Note will be made at the Corporate Trust Office of the Trustee or such other office or agency of the Company as may be designated for such purpose, in such currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that each installment of interest, premium, if any, and principal on this Note may at the Company’s option be paid in immediately available funds by transfer to an account maintained by the payee located in the United States of America.

Time of Payment. In any case where any Interest Payment Date, the Maturity Date or any date fixed for redemption or repayment of the Notes shall not be a Business Day, then (notwithstanding any other provision of the Indenture or this Note), payment of principal or interest, if any, need not be made on such date, but may be made on the next succeeding Business Day with the same force and effect as if made on such Interest Payment Date, the Maturity Date or the date so fixed for redemption or repayment, and no interest shall accrue in respect of the delay.

General. This Note is one of a duly authorized security of the Company, issued and to be issued under an indenture (the “Indenture”), dated as of August 12, 2015, between the Company and The Bank of New York Mellon Trust Company, N.A. (herein called the “Trustee,” which term includes any successor Trustee under the Indenture with respect to a series of which this Note is a part). Reference is hereby made to the Indenture for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Notes, and of the terms upon which the Notes are, and are to be, authenticated and delivered. This Note is one of a duly authorized series of Notes designated as “2.125% Senior Notes due 2018” (collectively, the “Notes”), initially limited in aggregate principal amount to $1,000,000,000.

Further Issuance. The Company may from time to time, without the consent of the Holders of the Notes, issue additional Securities (the “Additional Securities”) of this series having the same ranking and the same interest rate, maturity and other terms as the Notes. Any Additional Securities of this series and the Notes will constitute a single series under the Indenture and all references to the Notes shall include the Additional Securities unless the context otherwise requires.

Events of Default. If an Event of Default with respect to the Notes shall have occurred and be continuing, the principal of the Notes may be declared due and payable in the manner and with the effect provided in the Indenture.

Sinking Fund. The Notes are not subject to any sinking fund.

Optional Redemption. The Notes will be redeemable at any time, at the option of the Company, in whole or from time to time in part, upon not less than 30 nor more than 60 days’ prior notice, on any date prior to their Stated Maturity at a Redemption Price, calculated pursuant to the Indenture, which includes accrued interest thereon, if any, to, but not including, the Redemption Date. In the case of any partial redemption, selection of the Notes for redemption will be made by lottery or other method in accordance with the applicable procedures of DTC. If any Note is to be redeemed in part only, the notice of redemption relating to such Note shall state the portion of the principal amount thereof to be redeemed; provided that the principal amount of any Note remaining outstanding after a redemption in part shall be $2,000 or a higher integral multiple of $1,000 in excess thereof. A new Note in principal amount equal to the unredeemed portion thereof will be issued in the name of the Holder thereof upon cancellation of this Note.

Special Mandatory Redemption. Within five Business Days following the earlier of (i) the date on which an Acqusition Termination Event occurs and (ii) July 14, 2016, if the Acquisition has not closed on or prior to such date, the Company shall be required to mail a notice of mandatory redemption to the Holders of the Notes fixing the Special Mandatory Redemption Date. On such Special Mandatory Redemption Date, the Company shall be required to redeem the Notes, in whole but not in part, at the Special Mandatory Redemption Price.

Repurchase upon a Change of Control Triggering Event. Upon the occurrence of a Change of Control Triggering Event with respect to the Notes, the Company shall be required to make an offer to repurchase the Notes on the terms set forth in the Indenture.

Restrictive Covenants. The Indenture contains certain covenants that, among other things, limit the ability of the Company and its Subsidiaries to create liens or the ability of the Company to consolidate, merge or sell, transfer or lease all or substantially all of its assets.

Defeasance and Covenant Defeasance. The Indenture contains provisions for defeasance at any time of (a) the entire indebtedness of the Company on this Note and (b) certain restrictive covenants and the related defaults and Events of Default, upon compliance by the Company with certain conditions set forth therein, which provisions apply to this Note.

Modification and Waivers; Obligations of the Company Absolute. The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the Holders of the Notes of any series. Such amendment may be effected under the Indenture at any time by the Company, and the Trustee with the consent of the Notes of not less than a majority in aggregate principal amount of the outstanding Notes of such series affected thereby. The Indenture also contains provisions permitting the Holders of not less than a majority in aggregate principal amount of the Notes at the time outstanding, on behalf of the Holders of all outstanding Notes, to waive compliance by the Company with certain

provisions of the Indenture. Furthermore, provisions in the Indenture permit the Holders of not less than a majority in aggregate principal amount of the outstanding Notes of individual series to waive on behalf of all of the Holders of Notes of such individual series certain past defaults under the Indenture and their consequences. Any such consent or waiver shall be conclusive and binding upon the Holder of this Note and upon all future Holders of this Note and of any Note issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Note.

No reference herein to the Indenture and no provision of this Note or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of and interest on this Note at the time, place, and rate, and in the currency, herein prescribed.

No Recourse Against Others. No director, officer, agent, employee, incorporator, stockholder, partner, member, or manager of the Company shall have any liability for any obligations of the Company under any Notes, the Indenture or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder of the Notes by accepting a Note waives and releases all such liability. The waiver and release are part of the consideration for issuance of the Notes.

Limitation on Suits. As set forth in, and subject to, the provisions of the Indenture, no Holder of any Note will have any right to institute any proceeding with respect to the Indenture or for any remedy thereunder, unless such Holder shall have previously given to the Trustee written notice of a continuing Event of Default with respect to this series, the Holders of a majority in principal amount of the outstanding Notes shall have made written request to the Trustee, and offered indemnity satisfactory to the Trustee, to institute such proceedings as Trustee, and the Trustee shall not have received from the Holders of a majority in principal amount of the outstanding Notes a direction inconsistent with such request and shall have failed to institute such proceeding within 60 days; provided, however, that such limitations do not apply to a suit instituted by the Holder hereof for the enforcement of payment of the principal of or interest on this Note on or after the respective due dates expressed herein.

Authorized Denominations. The Notes are issuable only in registered form without coupons in minimum denominations of $2,000 or a higher integral multiple of $1,000 in excess thereof.

Registration of Transfer or Exchange. As provided in the Indenture and subject to certain limitations herein and therein set forth, the transfer of this Note is registrable in the register of the Notes maintained by the Registrar upon surrender of this Note for registration of transfer, at the office or agency of the Company in any place where the principal of and interest on this Note are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Company and the Registrar, duly executed by the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Notes, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.

As provided in the Indenture and subject to certain limitations herein and therein set forth, the Notes are exchangeable for a like aggregate principal amount of Notes of different authorized denominations, as requested by the Holders surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Note for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Holder as the owner hereof for all purposes (except with respect to certain payments of Defaulted Interest), whether or not this Note be overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to the contrary.

Defined Terms. All terms used in this Note, which are defined in the Indenture and are not otherwise defined herein, shall have the meanings assigned to them in the Indenture.

Governing Law. This Note shall be governed by and construed in accordance with the laws of the State of New York.

Unless the certificate of authentication hereon has been executed by the Trustee by manual signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

[Remainder of page intentionally left blank]

IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed and attested.

Dated: August 12, 2015

TRUSTEE’S CERTIFICATE OF AUTHENTICATION

This is one of the Notes of the series designated therein referred to in the within-mentioned Indenture.

ASSIGNMENT FORM

I or we assign and transfer this Note to

(Print or type name, address and zip code of assignee or transferee)

(Insert Social Security or other identifying number of assignee or transferee)

and irrevocably appoint _________________________________________________ agent to transfer this Note on the books of the Company. The agent may substitute another to act for him.

SCHEDULE OF INCREASES AND DECREASES IN GLOBAL NOTE

Celgene Corporation

2.125% Senior Note due 2018

The initial principal amount of this Global Note is $___________. The following increases or decreases in this Global Note have been made: