WARRANT TO PURCHASE 4,817 SHARES OF SERIES A CONVERTIBLE PREFERRED STOCK

<PAGE>

Exhibit 4.5

NEITHER THIS WARRANT NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT

HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. NO SALE OR

DISPOSITION MAY BE EFFECTED EXCEPT IN COMPLIANCE WITH RULE 144 UNDER SAID ACT OR

WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN OPINION OF

COUNSEL FOR THE HOLDER, SATISFACTORY TO THE COMPANY, THAT SUCH REGISTRATION IS

NOT REQUIRED UNDER THE ACT OR RECEIPT OF A NO-ACTION LETTER FROM THE SECURITIES

AND EXCHANGE COMMISSION.

WARRANT TO PURCHASE 4,817 SHARES OF

SERIES A CONVERTIBLE PREFERRED STOCK

January 8, 2004

THIS CERTIFIES THAT, for value received, GENERAL ELECTRIC CAPITAL CORPORATION

("Holder") is entitled to subscribe for and purchase four thousand eight hundred

seventeen (4,817) shares of the fully paid and no assessable Series A

Convertible Preferred Stock (the "Shares" or the "Series A Preferred Stock") of

Predix Pharmaceuticals Holdings, Inc., a Delaware corporation (the "Company"),

at the Warrant Price (as hereinafter defined), pursuant to that certain

equipment lease financing agreement by and between the Holder and the Company

dated December 3, 2002, subject to the provisions and upon the terms and

conditions hereinafter set forth.

1. Warrant Price. The Warrant Price shall initially be Ten and 00/100 dollars

($10.00) per share, subject to adjustment as provided in Section 7 below.

2. Conditions to Exercise. The purchase right represented by this Warrant may be

exercised at any time, or from time to time, in whole or in part during the term

commencing on the date hereof and ending at 5:00 P.M. Pacific time on the tenth

anniversary of the date of this Warrant (the "Expiration Date").

3. Method of Exercise; Payment; Issuance of Shares; Issuance of New Warrant.

(a) Cash Exercise. Subject to Section 2 hereof, the purchase right

represented by this Warrant may be exercised by the Holder hereof, in whole or

in part, by the surrender of this Warrant (with a duly executed Notice of

Exercise in the form attached hereto) at the principal office of the Company (as

set forth in Section 18 below) and by payment to the Company, by check, of an

amount equal to the then applicable Warrant Price per share multiplied by the

number of shares then being purchased. In the event of any exercise of the

rights represented by this Warrant, certificates for the shares of stock so

purchased shall be in the name of, and delivered to, the Holder hereof, or as

such Holder may direct (subject to the terms of transfer contained herein and

upon payment by such Holder hereof of any applicable transfer taxes). Such

delivery shall be made within 30 days after exercise of the Warrant and at the

Company's expense and, unless this Warrant has been fully exercised or expired,

a new Warrant having terms and conditions substantially identical to this

Warrant and representing the portion of the Shares, if any, with respect to

which this Warrant shall not have been exercised, shall also be issued to the

Holder hereof within 30 days after exercise of the Warrant.

<PAGE>

(b) Net Issue Exercise. Holder may also elect to receive shares equal to

the value of this Warrant (or of any portion thereof remaining unexercised) by

surrender of this Warrant at the principal office of the Company together with

notice of such election, in which event the Company shall issue to Holder the

number of shares of Series A Preferred Stock computed using the following

formula:

X = Y (A-B)

-------

A

Where X = the number of shares of Series A Preferred Stock to be issued to

Holder.

Y = the number of shares of Series A Preferred Stock purchasable under

this Warrant (at the date of such calculation).

A = the Fair Market Value of one share of the Series A Preferred Stock (at

the date of such calculation).

B = Warrant Price (as adjusted to the date of such calculation).

(c) Fair Market Value. For purposes of this Section 3, Fair Market Value

of one share of Series A Preferred Stock shall mean:

(i) The average of the closing bid and asked prices of the Company's

common stock, $0.01 par value (the "Common Stock") quoted in the

Over-The-Counter Market Summary, the last reported sale price quoted on

the Nasdaq National Market or on any exchange on which the Common Stock

is listed, whichever is applicable, as published in the Western Edition

of the Wall Street Journal for the ten (10) trading days prior to the

date of determination of Fair Market Value; or

(ii) In the event of an exercise in connection with a merger,

acquisition or other consolidation in which the Company is not the

surviving entity, the per share Fair Market Value for the Stock shall

be the value to be received per share of Series A Preferred Stock by

all holders of the Series A Preferred Stock in such transaction as

determined by the Board of Directors; or

(iii) In any other instance, the per share Fair Market Value for the

Series A Preferred Stock shall be as determined in good faith by the

Company's Board of Directors.

In the event of 3(c)(ii) or 3(c)(iii), above, the Company's Board of

Directors shall prepare a certificate, to be signed by an authorized

officer of the Company, setting forth in reasonable detail the basis

for and method of determination of the per share Fair Market Value of

the Stock. The Board will also certify to the Holder that this per

share Fair Market Value will be applicable to all holders of the Series

2

<PAGE>

A Preferred Stock. Such certification must be made to Holder at least

thirty (30) business days prior to the proposed effective date of the

merger, consolidation, sale, or other triggering event as defined in

3(c)(ii) or 3(c)(iii).

(d) Automatic Exercise. So long as the Fair Market Value of the Warrant is

equal to or greater than the Warrant Price, to the extent this Warrant is not

previously exercised, it shall be automatically exercised in accordance with

Sections 3(b) and 3(c) hereof (even if not surrendered) immediately before its

expiration, involuntary termination or cancellation.

4. Representations and Warranties of Holder and the Company.

(a) Representations and Warranties by Holder. The Holder represents and

warrants to the Company with respect to his purchase as follows:

(i) The Holder has substantial experience in evaluating and investing in

private placement transactions of securities of companies similar to the

Company so that the Holder is capable of evaluating the merits and risks

of its investment in the Company and has the capacity to protect its

interests.

(ii) Except for transfer to a Holder's affiliates, the Holder is acquiring

the Warrant and the Shares of Series A Preferred Stock issuable upon

exercise of the Warrant (collectively the "Securities") for investment for

its own account and not with a view to, or for resale in connection with,

any distribution thereof. The Holder understands that the Securities have

not been registered under the Securities Act of 1933, as amended (the

"Act") by reason of a specific exemption from the registration provisions

of the Act which depends upon, among other things, the bona fide nature of

the investment intent as expressed herein.

(iii) The Holder acknowledges that the Securities must be held

indefinitely unless subsequently registered under the Act or an exemption

from such registration is available. The Holder is aware of the provisions

of Rule 144 promulgated under the Act.

(iv) The Holder is an "accredited investor" within the meaning of

Regulation D promulgated under the Act.

(v) The Holder has had an opportunity to discuss the Company's business,

management and financial affairs with its management and an opportunity to

review the Company's facilities. The Holder understands that such

discussions, as well as the written information issued by the Company,

were intended to describe the aspects of the Company's business and

prospects which the Company believes to be material but were not

necessarily a thorough or exhaustive description.

(b) Company hereby represents and warrants to Holder that the statements in

the following paragraphs of this Section 4(b) are true and correct as of the

date hereof.

(i) Corporate Organization and Authority. The Company (a) is a corporation

duly organized, validly existing, and in good standing in its jurisdiction

of

3

<PAGE>

incorporation, (b) has the corporate power and authority to own and

operate its properties and to carry on its business as now conducted and

as proposed to be conducted; and (c) is qualified as a foreign corporation

in all jurisdictions where the failure to be so qualified would have a

material adverse effect on the Company.

(ii) Corporate Power. The Company has all requisite legal and corporate

power and authority to execute, issue and deliver the Warrant, to issue

the Series A Preferred Stock issuable upon exercise or conversion of the

Warrant, and to carry out and perform its obligations under the Warrant

and any related agreements.

(iii) Authorization; Enforceability. All corporate action on the part of

Company, its officers, directors and shareholders necessary for the

authorization, execution, delivery and performance of its obligations

under this Warrant and for the authorization, issuance and delivery of the

Warrant and Stock issuable upon exercise of the Warrant has been taken and

this Warrant constitutes the legally binding and valid obligation of

Company enforceable in accordance with its terms.

(iv) Valid Issuance of Warrant and Series A Preferred Stock. The Warrant

has been validly issued and is free of restrictions on transfer other than

restrictions on transfer set forth herein and under applicable state and

federal securities laws. The Series A Preferred Stock issuable upon

conversion of this Warrant, when issued, sold and delivered in accordance

with the terms of this Warrant for the consideration expressed herein,

will be duly and validly issued, fully paid and no assessable, and will be

free of restrictions on transfer other than restrictions on transfer under

this Warrant and under applicable state and federal securities laws.

Subject to applicable restrictions on transfer, the issuance and delivery

of the Warrant and the Series A Preferred Stock issuable upon conversion

of the Warrant are not subject to any preemptive or other similar rights

or any liens or encumbrances except as specifically set forth in Company's

Certificate of Incorporation, as amended and restated to date (the

"Certificate of Incorporation"), or this Warrant. The offer, sale and

issuance of the Warrant and Series A Preferred Stock, as contemplated by

this Warrant, are exempt from the prospectus and registration requirements

of applicable United States federal and state security laws, and neither

Company nor any authorized agent acting on its behalf has or will take any

action hereafter that would cause the loss of such exemption.

(v) No Conflict with Other Instruments. The execution, delivery, and

performance of this Warrant will not result in any violation of, be in

conflict with, or constitute a default under, with or without the passage

of time or the giving of notice (a) any provision of Company's Certificate

of Incorporation or by-laws; (b) any provision of any judgment, decree, or

order to which Company is a party or by which it is bound or an event

which results in the creation of any material lien, charge or encumbrance

upon any material assets of Company; (c) any

4

<PAGE>

contract, obligation, or commitment to which Company is a party or by

which it is bound; or (d) any statute, rule, or governmental regulation

applicable to Company.

(vi) Capitalization. As of the date of this Warrant, the authorized and

issued capital stock of Company is as set forth in Exhibit A. The

outstanding shares have been duly authorized and validly issued

(including, without limitation, issued in compliance with applicable

federal and state securities laws), are fully paid and nonassessable and

have been issued in compliance with the registration and prospectus

delivery requirements of the Securities Act and the registration and

qualification requirements of all applicable state securities laws, or in

compliance with applicable exemptions therefrom. The Company has reserved

4,817 shares of Series A Preferred Stock for issuance upon exercise of

this Warrant and 48,170 shares of Common Stock for the conversion of the

Series A Preferred Stock to Common Stock. Except as set forth on the

capitalization table attached to this Warrant in Exhibit A, there are no

outstanding warrants, options, conversion privileges, preemptive rights or

other rights or agreements to purchase or otherwise acquire or issue any

equity securities or convertible securities of Company, nor has the

issuance of any of the aforesaid rights to acquire securities of Company

been authorized.

(vii) Governmental Consents. No consent, approval, order or authorization

of, or registration, qualification, designation, declaration or filing

with, any federal, state or local governmental authority on the part of

Company is required in connection with the offer, sale or issuance of the

Warrant (and the Stock issuable upon the exercise of this Warrant), or the

consummation of any other transaction contemplated hereby, except for the

following: (a) the filing of a notice on Form D under the Act and (b) the

compliance with other applicable state securities laws, which compliance

will have occurred within the appropriate time periods therefore. The

offer, sale and issuance of the Warrant and the shares of Stock in

conformity with the terms of this Warrant are exempt from the registration

requirements of the Act and any applicable state laws.

(c) Within ten (10) days of the Holder providing notice to the Company of its

intent to exercise this Warrant, the Company will deliver to the Holder an

Officer's Certificate certifying that all of the representations and warranties

set forth in this Section 4 are true and correct in all material respects as of

the date of such certificate, except for Section 4(vi), in which case the

Company will deliver to the Holder an updated capitalization table in the same

form as set forth in Appendix A and make the representations and warranties set

forth in Section 4(vi) as they relate to the updated capitalization table.

5. Legends.

(a) Each certificate representing the Securities shall be endorsed with the

following legend:

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933

AND MAY NOT BE TRANSFERRED UNLESS COVERED BY AN

5

<PAGE>

EFFECTIVE REGISTRATION STATEMENT U