Litigation	12 Months Ended
Dec. 31, 2022
Litigation Settlement [Abstract]
Litigation	11. Litigation *Eversana Arbitration* On May 19, 2022, Eversana filed a Demand for Arbitration claiming approximately $4.5 million in damages against the Company with the American Arbitration Association entitled Eversana Life Sciences, LLC v. Humanigen, Inc. (AAA Case No. 01-22-0002-1591). The Demand contains two breach of contract claims related to the Eversana Agreement between the parties and a related agreement between the companies’ European subsidiaries, and a claim for unjust enrichment. Eversana asserts that the Company failed to pay it amounts due for work preparing for the potential commercializing of lenzilumab performed between April 1, 2021 and September 30, 2021. To date, requests for production and objections thereto have been exchanged. The arbitration hearing is currently set for August 2023. The Company denies Eversana’s claims and assertions and will continue to vigorously defend against them. *Avid Settlement* On February 21, 2023, the Company and Avid Bioservices, Inc. (“Avid”) entered into a Settlement Agreement (the “Settlement Agreement”) providing for a conditional resolution of certain previously reported disputes between the Company and Avid arising pursuant to the commercial agreements between the two parties (collectively, the “Lenzilumab Disputes”). Pursuant to the Settlement Agreement, the Company made a one-time payment of $3.0 million to Avid (the “Settlement Payment”). In addition, the parties mutually agreed that, effective upon the expiration of 120 days from the date of the Settlement Agreement and only if Humanigen has not by such date filed for or been placed into bankruptcy or commenced an assignment for the benefit of creditors or other insolvency proceeding, the parties will dismiss the pending Lenzilumab Disputes and release and discharge each other from all existing claims, demands, causes of actions, charges and grievances of any kind arising out of, or relating to, the Lenzilumab Disputes and the commercial agreements between the parties, which were terminated in accordance with their respective terms. *Catalent Settlement* On December 16, 2022, the Company and Catalent entered into a Settlement Agreement (the “Settlement Agreement”) resolving certain previously reported disputes between the Company and Catalent that had arisen under the Multiple Facility Clinical Supply and Services Agreement (the “MSA”) dated July 31, 2020, by and between Catalent and the Company, pursuant to which Catalent had agreed to perform certain services relating to the manufacturing of lenzilumab, the Company’s lead product candidate. Pursuant to the Settlement Agreement, the Company agreed to make a one-time payment of $12 million (the “Settlement Payment”) to Catalent in full satisfaction of all of the Company’s payment obligations under the MSA for products and prior services, as well as cancellation fees Catalent claimed to be owed. In consideration of its receipt of the Settlement Payment, which the Company made on December 22, 2022, Catalent waived and released Catalent’s rights to pursue all payments, claims, or invoices for such products and services and cancellation fees, as well as for some limited additional work to be performed by Catalent, quantified at approximately $23.5 million in the aggregate. The terms and conditions of the MSA generally will remain in full force and effect with respect to any ongoing activities and additional work to be performed by Catalent. *Savant Litigation* The Company was previously involved in litigation against Savant Neglected Diseases, LLC (“Savant”). In March 2022, the Company and Savant reached a confidential settlement. Accordingly, the litigation involving Savant was dismissed on March 31, 2022. *Thermo Litigation* Thermo has notified the Company that they have stopped production and have issued a demand for payment for unreleased batches of product. There is significant drug product that was in production at Thermo for which material has not yet been released by the Company because the batches produced are out of specification. On October 24, 2022, Thermo filed a lawsuit against the Company in Delaware Superior Court (Patheon Biologics, Inc. v. Humanigen, Inc., Case No. N22C-10-185 MMJ) for $25.9 million. The Company has filed a countersuit against Thermo for breach of contract seeking more than $37.5 million. The Company denies Thermo’s claims and assertions and will vigorously defend against them. *Securities Class Action Litigation* On August 26, 2022, a putative securities class action complaint captioned Pieroni v. Humanigen Inc., et al., Case No. 22-cv-05258, was filed in the United States District Court for the District of New Jersey against the Company, its Chief Executive Officer, Dr. Cameron Durrant, and its former Chief Financial Officer, Timothy Morris. On October 17, 2022, a second putative securities class action complaint captioned Greenbaum v. Humanigen Inc., et al., Case No. 22-cv-06118, was filed in the United States District Court for the District of New Jersey against the Company, Dr. Durrant, Mr. Morris, and the Company’s Chief Scientific Officer, Dale Chappell. The complaints assert claims and seek damages for alleged violations of sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The two actions have been consolidated and a single lead plaintiff and co-lead law firms have been appointed. The Company anticipates filing a Motion to Dismiss in late May 2023. The Company believes that the allegations in the putative complaints are without merit and will vigorously defend against them. *Shareholder Derivative Litigation* On January 19, 2023, a derivative lawsuit captioned Chul Yang derivatively on behalf of Humanigen, Inc. v. Durrant, et al., Case No. 2:23-cv-00235, was filed in the United States District Court for the District of New Jersey against the company’s Chief Executive Officer, Dr. Cameron Durrant, its former Chief Financial Officer, Timothy Morris, and each of its Directors. The complaint asserts claims and seeks damages against all of the defendants for alleged violations of section 14(a) of the Securities Exchange Act of 1934 and Rule 14a-9 promulgated thereunder, breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets, and against Dr. Durrant and Mr. Morris for alleged violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The Company anticipates this matter being stayed pending initial rulings in the consolidated securities class action matter. The Company believes that the allegations in the derivative action are without merit and will vigorously defend against them.

Litigation

12 Months Ended

Dec. 31, 2022

11. Litigation

Eversana Arbitration

On May 19, 2022, Eversana filed a Demand for Arbitration claiming approximately $4.5 million in damages against the Company with the American Arbitration Association entitled Eversana Life Sciences, LLC v. Humanigen, Inc. (AAA Case No. 01-22-0002-1591). The Demand contains two breach of contract claims related to the Eversana Agreement between the parties and a related agreement between the companies’ European subsidiaries, and a claim for unjust enrichment. Eversana asserts that the Company failed to pay it amounts due for work preparing for the potential commercializing of lenzilumab performed between April 1, 2021 and September 30, 2021. To date, requests for production and objections thereto have been exchanged. The arbitration hearing is currently set for August 2023. The Company denies Eversana’s claims and assertions and will continue to vigorously defend against them.

Avid Settlement

On February 21, 2023, the Company and Avid Bioservices, Inc. (“Avid”) entered into a Settlement Agreement (the “Settlement Agreement”) providing for a conditional resolution of certain previously reported disputes between the Company and Avid arising pursuant to the commercial agreements between the two parties (collectively, the “Lenzilumab Disputes”).

Pursuant to the Settlement Agreement, the Company made a one-time payment of $3.0 million to Avid (the “Settlement Payment”). In addition, the parties mutually agreed that, effective upon the expiration of 120 days from the date of the Settlement Agreement and only if Humanigen has not by such date filed for or been placed into bankruptcy or commenced an assignment for the benefit of creditors or other insolvency proceeding, the parties will dismiss the pending Lenzilumab Disputes and release and discharge each other from all existing claims, demands, causes of actions, charges and grievances of any kind arising out of, or relating to, the Lenzilumab Disputes and the commercial agreements between the parties, which were terminated in accordance with their respective terms.

Catalent Settlement

On December 16, 2022, the Company and Catalent entered into a Settlement Agreement (the “Settlement Agreement”) resolving certain previously reported disputes between the Company and Catalent that had arisen under the Multiple Facility Clinical Supply and Services Agreement (the “MSA”) dated July 31, 2020, by and between Catalent and the Company, pursuant to which Catalent had agreed to perform certain services relating to the manufacturing of lenzilumab, the Company’s lead product candidate.

Pursuant to the Settlement Agreement, the Company agreed to make a one-time payment of $12 million (the “Settlement Payment”) to Catalent in full satisfaction of all of the Company’s payment obligations under the MSA for products and prior services, as well as cancellation fees Catalent claimed to be owed. In consideration of its receipt of the Settlement Payment, which the Company made on December 22, 2022, Catalent waived and released Catalent’s rights to pursue all payments, claims, or invoices for such products and services and cancellation fees, as well as for some limited additional work to be performed by Catalent, quantified at approximately $23.5 million in the aggregate.

The terms and conditions of the MSA generally will remain in full force and effect with respect to any ongoing activities and additional work to be performed by Catalent.

Savant Litigation

The Company was previously involved in litigation against Savant Neglected Diseases, LLC (“Savant”). In March 2022, the Company and Savant reached a confidential settlement. Accordingly, the litigation involving Savant was dismissed on March 31, 2022.

Thermo Litigation

Thermo has notified the Company that they have stopped production and have issued a demand for payment for unreleased batches of product. There is significant drug product that was in production at Thermo for which material has not yet been released by the Company because the batches produced are out of specification. On October 24, 2022, Thermo filed a lawsuit against the Company in Delaware Superior Court (Patheon Biologics, Inc. v. Humanigen, Inc., Case No. N22C-10-185 MMJ) for $25.9 million. The Company has filed a countersuit against Thermo for breach of contract seeking more than $37.5 million. The Company denies Thermo’s claims and assertions and will vigorously defend against them.

Securities Class Action Litigation

On August 26, 2022, a putative securities class action complaint captioned Pieroni v. Humanigen Inc., et al., Case No. 22-cv-05258, was filed in the United States District Court for the District of New Jersey against the Company, its Chief Executive Officer, Dr. Cameron Durrant, and its former Chief Financial Officer, Timothy Morris. On October 17, 2022, a second putative securities class action complaint captioned Greenbaum v. Humanigen Inc., et al., Case No. 22-cv-06118, was filed in the United States District Court for the District of New Jersey against the Company, Dr. Durrant, Mr. Morris, and the Company’s Chief Scientific Officer, Dale Chappell. The complaints assert claims and seek damages for alleged violations of sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The two actions have been consolidated and a single lead plaintiff and co-lead law firms have been appointed. The Company anticipates filing a Motion to Dismiss in late May 2023. The Company believes that the allegations in the putative complaints are without merit and will vigorously defend against them.

Shareholder Derivative Litigation

On January 19, 2023, a derivative lawsuit captioned Chul Yang derivatively on behalf of Humanigen, Inc. v. Durrant, et al., Case No. 2:23-cv-00235, was filed in the United States District Court for the District of New Jersey against the company’s Chief Executive Officer, Dr. Cameron Durrant, its former Chief Financial Officer, Timothy Morris, and each of its Directors. The complaint asserts claims and seeks damages against all of the defendants for alleged violations of section 14(a) of the Securities Exchange Act of 1934 and Rule 14a-9 promulgated thereunder, breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets, and against Dr. Durrant and Mr. Morris for alleged violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. The Company anticipates this matter being stayed pending initial rulings in the consolidated securities class action matter. The Company believes that the allegations in the derivative action are without merit and will vigorously defend against them.