I. GENERAL INSTRUCTIONS

1. To recover as a member of the Settlement Class based on your claims in the action entitled In re Humanigen, Inc. Securities Litigation, Case No. 2:22-cv-05258-WJM-AME (the “Litigation”), you must complete and, electronically sign this Proof of Claim and Release. If you fail to file a properly submitted Proof of Claim and Release, your claim may be rejected and you may be precluded from any recovery from the Settlement Fund created in connection with the proposed settlement of the Litigation.

2. Submission of this Proof of Claim and Release, however, does not assure that you will share in the proceeds of settlement in the Litigation.

3. YOU MUST SUBMIT YOUR COMPLETED AND SIGNED PROOF OF CLAIM AND RELEASE ON OR BEFORE MARCH 7, 2024.

4. If you are a Settlement Class Member, you are bound by the terms of any judgment entered in the Action, WHETHER OR NOT YOU SUBMIT A PROOF OF CLAIM AND RELEASE FORM, unless you timely and validly request exclusion from the Settlement Class pursuant to the Notice.

II. CLAIMANT IDENTIFICATION

1. If you purchased or acquired Humanigen securities during the period from May 16, 2020, to July 12, 2022, inclusive, and held the certificate(s) in your name, you are the beneficial purchaser or acquirer as well as the record purchaser or acquirer. If, however, the certificate(s) were registered in the name of a third party, such as a nominee or brokerage firm, you are the beneficial purchaser and the third party is a record purchaser.

2. Use Part I of this form entitled “Claimant Identification” to identify each purchaser of record (“nominee”), if different from the beneficial purchaser of Humanigen securities which form the basis of this claim. THIS CLAIM MUST BE FILED BY THE ACTUAL BENEFICIAL PURCHASER OR PURCHASERS, OR THE LEGAL REPRESENTATIVE OF SUCH PURCHASER OR PURCHASERS OF THE HUMANIGEN SECURITIES UPON WHICH THIS CLAIM IS BASED.

3. All joint purchasers must electronically sign this claim. Executors, administrators, guardians, conservators, and trustees must complete and sign this claim on behalf of Persons represented by them; their authority must accompany this claim and their titles or capacities must be stated. The Social Security (or Taxpayer Identification) Number and telephone number of the beneficial owner may be used in verifying the claim. Failure to provide the foregoing information could delay verification of your claim or result in rejection of the claim.

III. CLAIM FORM

1. Use Part II and Part III of this form to supply all required details of your transaction(s).

2. On the schedules, provide all of the requested information with respect to all of your purchases or acquisitions and all of your sales of Humanigen securities which took place at any time beginning May 16, 2020, through October 10, 2022, whether such transactions resulted in a profit or a loss and even though the Class Period ends on July 12, 2022. Failure to report all such transactions may result in the rejection of your claim.

3. List each transaction in the Class Period separately and in chronological order by trade date, beginning with the earliest. You must accurately provide the month, day, and year of each transaction you list. For option transactions, you must also provide the number of contracts, maturity date, strike price, and transaction type (e.g., buy to open, buy to close, sell to open, sell to close).

4. Broker confirmations or other documentation of your transactions in Humanigen securities should be attached to your claim. Failure to provide this documentation could delay verification of your claim or result in rejection of your claim.

5. The above requests are designed to provide the minimum amount of information necessary to process the simplest claims.

6. NOTICE REGARDING ELECTRONIC FILES: Certain claimants with large numbers of transactions may request, or may be requested, to submit information regarding their transactions in electronic files. All such claimants MUST also submit a manually signed paper Proof of Claim and Release, whether or not they also submit electronic copies. If you wish to submit your claim electronically, you must contact the Claims Administrator at info@HumanigenSecuritiesLitigation.com or 1-877-354-3785 to obtain the mandatory file layout.

Any file that does not comply with the required electronic filing format will be subject to rejection. No electronic files will be considered to have been properly submitted unless the Claims Administrator issues to the claimant a written acknowledgment of receipt and acceptance of electronically submitted data. Do not assume that your file has been received until you receive this email. If you do not receive such an email within 10 days of your submission, you should contact the Claims Administrator’s electronic filing department at efiling@abdata.com to inquire about your file and confirm it was received.