CYTOPHERX, INC. WARRANT TO PURCHASE PREFERRED STOCK No. [•] [•]

Exhibit 4.5

THIS WARRANT AND THE UNDERLYING SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO SUCH SECURITIES UNDER THE ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

THIS CERTIFIES THAT, for value received, [•], with its principal office at [•], or assigns (the “Holder”), is entitled to subscribe for and purchase from CYTOPHERX, INC., a Delaware corporation, with its principal office at ▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇ ▇▇▇▇▇ (the “Company”) Exercise Shares at the Exercise Price (each as defined below and each subject to adjustment as provided herein). This Warrant is being issued as one of a series of warrants (the “Warrants”) pursuant to the terms of the Note and Warrant Purchase Agreement, dated [•], as amended, by and among the Company and the Purchasers named therein (the “Purchase Agreement”). Unless indicated otherwise, the aggregate number of Exercise Shares that Holder may purchase by exercising this warrant is equal to (a) one hundred percent (100%), multiplied by (B) such Holder’s Supplemental Warrant Coverage Amount (as defined in the Purchase Agreement), divided by (C) the Conversion Price (as defined in the Supplemental Notes), subject to adjustment pursuant to the terms hereof, including but not limited to adjustments pursuant to Section 5 below. The “Supplemental Warrant Coverage Amount” applicable to this Warrant shall be the Supplemental Warrant Coverage Amount set forth for the Supplemental Closing in the Schedule of Purchasers attached to the Fourth Amendment to the Purchase Agreement.

1. DEFINITIONS. Capitalized terms used but not defined herein shall have the meanings set forth in the Purchase Agreement. As used herein, the following terms shall have the following respective meanings:

(a) “Exercise Period” shall mean the period commencing with the earlier of (x) the date the Supplemental Notes convert into Equity Securities, and (y) the date the Supplemental Notes are actually fully repaid, and ending seven (7) years later.

(b) “Exercise Price” shall mean (i) the Conversion Price per Exercise Share if the corresponding Supplemental Note is converted into Equity Securities, and (ii) the Series C Original Issue Price (as defined in the Company’s Amended and Restated Certificate of Incorporation as in effect from time to time (the “Restated Charter”)), subject (if applicable) to adjustment pursuant to Section 5 below.

(c) “Exercise Shares” shall mean shares of the Company’s Preferred Stock issuable upon exercise of this Warrant. The series of Preferred Stock issuable pursuant to this Warrant shall be (i) the same series of Preferred Stock as issued upon conversion of the corresponding Supplemental Note if such Supplemental Note is converted, and (ii) Series C Preferred Stock of the Company, if the Supplemental Note is not converted.

2. EXERCISE OF WARRANT.

2.1 Cash Exercise. The rights represented by this Warrant may be exercised in whole or in part at any time during the Exercise Period, by delivery of the following to the Company at its address set forth above (or at such other address as it may designate by notice in writing to the Holder):

(a) An executed Notice of Exercise in the form attached hereto;

(b) Payment of the Exercise Price either (i) in cash or by check, or (ii) by cancellation of indebtedness; and

(c) This Warrant.

2.2 Net Issue Exercise. Notwithstanding any provisions of this Warrant to the contrary, if the fair market value of one Exercise Share is greater than the Exercise Price (at the date of calculation as set forth below), in lieu of exercising this Warrant by payment of cash, the Holder may elect to receive shares equal to the value (as determined below) of this Warrant (or the portion thereof being cancelled) by surrender of this Warrant at the principal office of the Company together with the properly endorsed Notice of Exercise in which event the Company shall issue to the Holder a number of Exercise Shares computed using the following formula:

Where X = the number of Exercise Shares to be issued to the Holder

For purposes of the above calculation, the fair market value of one Exercise Share shall be determined by the Company’s Board of Directors in good faith; provided, however, that in the event that this Warrant is exercised pursuant to this Section 2.2 in connection with the Company’s initial public offering of its Common Stock, the fair market value per share shall be the product of (i) the per share offering price to the public of the Company’s initial public offering, and (ii) the number of shares of Common Stock into which each Exercise Share is convertible at the time of such exercise.

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2.3 Exercise Processes. Upon the exercise of the rights represented by this Warrant, a certificate or certificates for the Exercise Shares so purchased, registered in the name of the Holder or persons affiliated with the Holder, if the Holder so designates, shall be issued and delivered to the Holder within a reasonable time after the rights represented by this Warrant shall have been so exercised. In the event that this Warrant is being exercised for less than all of the then-current number of Exercise Shares purchasable hereunder, the Company shall, concurrently with the issuance by the Company of the number of Exercise Shares for which this Warrant is then being exercised, issue a new Warrant exercisable for the remaining number of Exercise Shares purchasable hereunder. The person in whose name any certificate or certificates for Exercise Shares are to be issued upon exercise of this Warrant shall be deemed to have become the holder of record of such shares on the date on which this Warrant was surrendered and payment of the Exercise Price was made, irrespective of the date of delivery of such certificate or certificates, except that, if the date of such surrender and payment is a date when the stock transfer books of the Company are closed, such person shall be deemed to have become the holder of such shares at the close of business on the next succeeding date on which the stock transfer books are open.

3. COVENANTS OF THE COMPANY.

3.1 Covenants as to Exercise Shares. The Company covenants and agrees that all Exercise Shares that may be issued upon the exercise of the rights represented by this Warrant will, upon issuance, be validly issued and outstanding, fully paid and nonassessable, and free from all taxes, liens and charges with respect to the issuance thereof. The Company further covenants and agrees that the Company will at all times during the Exercise Period, have authorized and reserved, free from pre-emptive rights, a sufficient number of shares of the series of equity securities comprising the Exercise Shares to provide for the exercise of the rights represented by this Warrant. If at any time during the Exercise Period the number of authorized but unissued shares of such series of the Company’s equity securities shall not be sufficient to permit exercise of this Warrant, the Company will take such corporate action as may, in the opinion of its counsel, be necessary to increase its authorized but unissued shares of such series of the Company’s equity securities to such number of shares as shall be sufficient for such purposes.

3.2 Notices of Record Date. In the event of any taking by the Company of a record of the holders of any class of securities for the purpose of determining the holders thereof who are entitled to receive any dividend or other distribution, the Company shall mail to the Holder, at least ten (10) days prior to the date specified herein, a notice specifying the date on which any such record is to be taken for the purpose of such dividend or distribution.

4. REPRESENTATIONS OF HOLDER.

4.1 Acquisition of Warrant for Personal Account. The Holder represents and warrants that it is acquiring the Warrant and the Exercise Shares solely for its account for investment and not with a view to or for sale or distribution of said Warrant or Exercise Shares or any part thereof. The Holder also represents that the entire legal and beneficial interests of the Warrant and Exercise Shares the Holder is acquiring is being acquired for, and will be held for, its account only.

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4.2 Securities Are Not Registered.

(a) The Holder understands that the Warrant and the Exercise Shares have not been registered under the Securities Act of 1933, as amended (the “Act”) on the basis that no distribution or public offering of the stock of the Company is to be effected. The Holder realizes that the basis for the exemption may not be present if, notwithstanding its representations, the Holder has a present intention of acquiring the securities for a fixed or determinable period in the future, selling (in connection with a distribution or otherwise), granting any participation in, or otherwise distributing the securities. The Holder has no such present intention.

(b) The Holder recognizes that the Warrant and the Exercise Shares must be held indefinitely unless they are subsequently registered under the Act or an exemption from such registration is available. The Holder recognizes that the Company has no obligation to register the Warrant or the Exercise Shares of the Company, or to comply with any exemption from such registration, except as provided in the Rights Agreement.

(c) The Holder is aware that neither the Warrant nor the Exercise Shares may be sold pursuant to Rule 144 adopted under the Act unless certain conditions are met, including, among other things, the existence of a public market for the shares, the availability of certain current public information about the Company, the resale following the required holding period under Rule 144 and the number of shares being sold during any three month period not exceeding specified limitations, Holder is aware that the conditions for resale set forth in Rule 144 have not been satisfied and that the Company presently has no plans to satisfy these conditions in the foreseeable future.

4.3 Disposition of Warrant and Exercise Shares.

(a) The Holder further agrees not to make any disposition of all or any part of the Warrant or Exercise Shares in any event unless and until:

(i) The Company shall have received a letter secured by the Holder from the Securities and Exchange Commission stating that no action will be recommended to the Commission with respect to the proposed disposition;

(ii) There is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in accordance with said registration statement; or

(iii) The Holder shall have notified the Company of the proposed disposition and shall have furnished the Company with a detailed statement of the circumstances surrounding the proposed disposition, and if reasonably requested by the Company, the Holder shall have furnished the Company with an opinion of counsel, reasonably satisfactory to the Company, for the Holder to the effect that such disposition will not require registration of such Warrant or Exercise Shares under the Act or any applicable state securities laws. The Company agrees that it will not require an opinion of counsel with respect to (A) transactions under Rule 144 of the Securities Act of 1933, as amended, except in unusual circumstances, or (B) transfers of this Warrant (or any portion hereof) to any Affiliate (as defined in the Rights Agreement).

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(b) The Holder understands and agrees that all certificates evidencing the shares to be issued to the Holder may bear the following legend:

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THE SECURITIES UNDER THE ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

4.4 Accredited Investor Status. The Holder is an “accredited investor” as defined in Regulation D promulgated under the Act.

4.5 Additional Restrictions on Transfer. Notwithstanding anything in this Warrant to the contrary, in no event shall the Holder be entitled to transfer this Warrant (in whole or in part or any interest herein) without also assigning the Holder’s rights and obligations under the Agreement, including without limitation the Holder’s rights and obligations pursuant to Section 2(b) of the Agreement, and it shall be a condition to any such transfer that the transferee agree in writing to be bound by the Agreement as if such transferee were a Purchaser under the Agreement.

5. ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF EXERCISE SHARES.

5.1 Changes in Securities. In the event of changes in the series of equity securities of the Company comprising the Exercise Shares by reason of stock dividends, splits, recapitalizations, reclassifications, combinations or exchanges of shares, separations, reorganizations, liquidations, or the like, the number and class of Exercise Shares available under the Warrant in the aggregate and the Exercise Price shall be correspondingly adjusted to give the Holder of the Warrant, on exercise for the same aggregate Exercise Price, the total number, class, and kind of shares as the Holder would have owned had the Warrant been exercised prior to the event and had the Holder continued to hold such shares until after the event requiring adjustment. For purposes of this Section 5, the “Aggregate Exercise Price” shall mean the aggregate Exercise Price payable in connection with the exercise in full of this Warrant. The form of this Warrant need not be changed because of any adjustment in the number of Exercise Shares subject to this Warrant.

5.2 Automatic Conversion. Upon the automatic conversion of all outstanding shares of the series of equity securities comprising the Exercise Shares, this Warrant shall become exercisable for that number of shares of Common Stock of the Company into which the Exercise Shares would then be convertible, so long as such shares, if this Warrant had been exercised prior to such offering, would have been converted into shares of the Company’s Common Stock pursuant to the Restated Charter. In such case, all references to “Exercise Shares” shall mean shares of the Company’s Common Stock issuable upon exercise of this Warrant, as appropriate.

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5.3 Reorganization. In the event of, at any time during the Exercise Period, any Deemed Liquidation (as defined in the Restated Charter (an “Organic Change”)), then, as a condition of such Organic Change, lawful and adequate provisions shall be made by the Company whereby the Holder hereof shall thereafter have the right to purchase and receive (in lieu of the Exercise Shares of the Company immediately theretofore purchasable and receivable upon the exercise of the rights represented hereby) such shares of stock, securities or other assets or property as may be issued or payable with respect to or in exchange for a number of outstanding shares of such Exercise Shares equal to the number of shares of such stock immediately theretofore purchasable and receivable upon the exercise of the rights represented hereby, and the Exercise Price shall be appropriately adjusted so that the Aggregate Exercise Price after such Organic Change shall be equal to the Aggregate Exercise Price immediately prior to such Organic Change.

6. FRACTIONAL SHARES. No fractional shares shall be issued upon the exercise of this Warrant as a consequence of any adjustment pursuant hereto. All Exercise Shares (including fractions) to be issued upon exercise of this Warrant shall be aggregated for purposes of determining whether the exercise would result in the issuance of any fractional share. If, after aggregation, the exercise would result in the issuance of a fractional share, the Company shall, in lieu of issuance of any fractional share, pay the Holder otherwise entitled to such fraction a sum in cash equal to the product resulting from multiplying the then current fair market value of one Exercise Share by such fraction.

7. NO STOCKHOLDER RIGHTS. This Warrant in and of itself shall not entitle the Holder to any voting rights or other rights as a stockholder of the Company.

8. TRANSFER OF WARRANT. Subject to applicable laws, the restrictions on transfer set forth on the first page of this Warrant, in Sections 4.3 and 4.5 of this Warrant or otherwise in this Warrant, and any restrictions applicable to the transfer of shares set forth in the Company’s bylaws, as they may be amended from time to time, this Warrant and all rights hereunder are transferable, by the Holder in person or by duly authorized attorney, upon delivery of this Warrant and the form of assignment attached hereto to any transferee designated by Holder. The transferee shall sign an investment letter in form and substance satisfactory to the Company.

9. LOST, STOLEN, MUTILATED OR DESTROYED WARRANT. If this Warrant is lost, stolen, mutilated or destroyed, the Company may, on such terms as to indemnity or otherwise as it may reasonably impose (which shall, in the case of a mutilated Warrant, include the surrender thereof), issue a new Warrant of like denomination and tenor as the Warrant so lost, stolen, mutilated or destroyed. Any such new Warrant shall constitute an original contractual obligation of the Company, whether or not the allegedly lost, stolen, mutilated or destroyed Warrant shall be at any time enforceable by anyone.

10. AMENDMENT. Any term of this Warrant may be amended or waived with the written consent of the Company and Holders of at least sixty-six and two-thirds percent (66-2/3%) in interest (based upon the number of Exercise Shares issuable upon exercise) of the outstanding Warrants provided that all Warrants are similarly amended or waived (without regard to economic effect). Upon the effectuation of such amendment or waiver in conformance with this Section 10, the Company shall promptly give written notice thereof to the record holders of the Warrants who have not previously consented thereto in writing.

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11. NOTICES, ETC. All notices required or permitted hereunder shall be in writing and shall be deemed effectively given: (a) upon personal delivery to the party to be notified, (b) when sent by confirmed telex, electronic mail or facsimile if sent during normal business hours of the recipient, if not, then on the next business day, (c) five (5) days after having been sent by registered or certified mail, return receipt requested, postage prepaid, or (d) one (1) day after deposit with a nationally recognized overnight courier, specifying next day delivery, with written verification of receipt. All communications shall be sent to the Company at the address set forth on the signature page hereto and to the Holder at the addresses set forth on the Schedule of Purchasers attached to the Purchase Agreement or at such other addresses as the Company or Holder may designate by ten (10) days’ advance written notice to the other parties hereto.

12. ACCEPTANCE. Receipt of this Warrant by the Holder shall constitute acceptance of and agreement to all of the terms and conditions contained herein.

13. GOVERNING LAW. This Warrant and all rights, obligations and liabilities hereunder shall be governed by and construed under the laws of the State of Delaware as applied to agreements among Delaware residents, made and to be performed entirely within the State of Delaware without giving effect to conflicts of laws principles.

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IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer as of [•].

[WARRANT SIGNATURE PAGE]

NOTICE OF EXERCISE

TO: CYTOPHERX, INC.

(1) ☐ The undersigned hereby elects to purchase __________ shares of __________ (the “Exercise Shares”) of Cytopherx, Inc, (the “Company”) pursuant to the terms of the attached Warrant, and tenders herewith payment of the exercise price in full, together with all applicable transfer taxes, if any.

☐ The undersigned hereby elects to purchase __________ shares of __________ (the “Exercise Shares”) of CytoPheryx, Inc. (the “Company”) pursuant to the terms of the net exercise provisions set forth in Section 2.2 of the attached Warrant, and shall tender payment of all applicable transfer taxes, if any.

(2) Please issue a certificate or certificates representing said Exercise Shares in the name of the undersigned or in such other name as is specified below:

(3) The undersigned represents that (i) the aforesaid Exercise Shares are being acquired for the account of the undersigned for investment and not with a view to, or for resale in connection with, the distribution thereof and that the undersigned has no present intention of distributing or reselling such shares; (ii) the undersigned is aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision regarding its investment in the Company; (iii) the undersigned is experienced in making investments of this type and has such knowledge and background in financial and business matters that the undersigned is capable of evaluating the merits and risks of this investment and protecting the undersigned’s own interests; (iv) the undersigned understands that Exercise Shares issuable upon exercise of this Warrant have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), by reason of a specific exemption from the registration provisions of the Securities Act, which exemption depends upon, among other things, the bona fide nature of the investment intent as expressed herein, and, because such securities have not been registered under the Securities Act, they must be held indefinitely unless subsequently registered under the Securities Act or an exemption from such registration is available; (v) the undersigned is aware that the aforesaid Exercise Shares may not be sold pursuant to Rule 144 adopted under the Securities Act unless certain conditions are met and until the undersigned has held the shares for the number of years prescribed by Rule 144, that among the conditions for use of the Rule is the availability of current information to the public about the Company and the Company has not made such information available and has no present plans to do so; and (vi) the undersigned agrees not to make any disposition of all or any part of the aforesaid shares of Exercise Shares unless and until there is then in effect a registration statement under the Securities Act covering such proposed disposition and such disposition is made in accordance with

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said registration statement, or, if reasonably requested by the Company, the undersigned has provided the Company with an opinion of counsel satisfactory to the Company (unless the Warrant provides no opinion is necessary for such transfer), stating that such registration is not required.

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ASSIGNMENT FORM

(To assign the foregoing Warrant, execute this form

and supply required information. Do not use this

form to purchase shares.)

FOR VALUE RECEIVED, the foregoing Warrant and all rights evidenced thereby are hereby assigned to

NOTE: The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without alteration or enlargement or any change whatever. Officers of corporations and those acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the foregoing Warrant.

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