Humanigen Announces Lenzilumab in COVID-19 Program Updates

• Type B Meeting With FDA Provided Feedback on Emergency Use Authorization Submission Plans
• Phase 3 Trial Expanded to Brazil With Seven Sites Actively Enrolling; Patients Already Dosed
• 17 Active Trial Sites in the US, Including California, Texas and Florida
• Approval From Mexican Regulatory Agency to Expand Study in Country With Fourth Highest Reported Deaths Worldwide
• Top-Line Data Planned for the Fourth Quarter of 2020

BURLINGAME, CA / ACCESSWIRE / October 2, 2020 / Humanigen, Inc., (NASDAQ:HGEN) ("Humanigen"), a clinical stage biopharmaceutical company focused on preventing and treating an immune hyper-response called ‘cytokine storm' with its lead drug candidate lenzilumab™, today announced updates on its lenzilumab in COVID-19 development program, including written guidance received from the US Food and Drug Administration (FDA) following a Type B meeting to obtain feedback on plans for an Emergency Use Authorization (EUA). FDA agreed that the Company's intended submission may be sufficient to support an EUA request, subject to Phase 3 trial data, and provided guidance and support for the Company's Biologics License Application and approval pathway. The Company also announced several updates on its Phase 3 registration study with lenzilumab which is continuing to enroll in the U.S. and Brazil, and now has been approved to expand to Mexico. The randomized, placebo-controlled, double-blinded Phase 3 trial currently has a total of 29 approved sites with 24 actively enrolling hospitalized adult COVID-19 patients who require supplemental oxygen and are at high risk of disease progression.

"FDA was very helpful and provided clear guidance on our EUA submission plan," said Cameron Durrant, MD, MBA, chief executive officer of Humanigen. "We are encouraged by our Type B meeting and remain confident in our program and preparedness plans in advance of a potential EUA."

"Lenzilumab is one of the few Phase 3 treatment options in development for COVID-19 and has the potential to be a first line treatment to improve time to recovery and prevent serious and potentially fatal outcomes in patients who are hospitalized with COVID-19. The addition of new trial sites in Brazil and Mexico expands access to this study, which is especially critical for regions experiencing a surge in cases, including centers which are already enrolling in the US in areas referred to as ‘hot-spots'," said Dale Chappell, MD, MBA, chief scientific officer of Humanigen. "Trial enrollment continues as we work towards top-line data announcement in the fourth quarter. In parallel, we are furthering our large-scale commercial manufacturing production efforts, having recently announced agreements with Thermo Fisher and Lonza, in addition to Catalent, which are planned to ensure access to lenzilumab if granted EUA."

Key lenzilumab COVID-19 development program updates include:

Updates from FDA Type B meeting:

• The Company's intended submission may be sufficient to support an EUA request, subject to Phase 3 trial data
• The FDA provided feedback on the Company's Chemistry, Manufacturing and Controls (CMC) plan, EUA labelling and the Statistical Analysis Plan (SAP) and agreed that no material changes are needed across these elements.

US Phase 3 clinical trial program updates:

• 17 trial sites are active in the US
• The study is continuing to enroll at sites including Los Angeles, Dallas, Orlando, Jacksonville, Charlotte, Atlanta and Minneapolis, cities associated with high rates of confirmed COVID-19 cases.[1]

Brazil Phase 3 clinical trial program updates:

• Seven of the 12 approved trial sites in Brazil are currently validated to begin enrolling patients.
• Several patients have been dosed across multiple sites in Brazil in four of the seven centers now enrolling patients.
• Program clinical trial investigators in Brazil stressed the importance of this program and urgency for enrollment during a recent investigator meeting.
• Brazil has more than 4.8 million reported cases of COVID-19 and has reported over 143,000 deaths, second in the world only to the US.[2]

Mexico Phase 3 clinical trial program updates:

• The Mexican regulatory agency, COFEPRIS, has granted permission to commence a Phase 3 study of lenzilumab in patients with COVID-19 in Mexico, expanding the strategic global reach of this program.

• Clinical trial sites are being activated to initiate patient enrollment in the study, which will follow the same protocol that was approved by the FDA and is running in the sites in US and Brazil; the data from all sites to be aggregated for Phase 3 purposes.
• Mexico has the fourth highest number of reported COVID-19 related deaths in the world and has reported more than 743,000 cases of COVID-19 in total.[3]

More details on Humanigen's programs in COVID-19 can be found on the Company's website at www.humanigen.com under the COVID-19 tab, and details of the US Phase 3 potential registration study can be found at clinicaltrials.gov using Identifier NCT04351152.

About Humanigen, Inc.
Humanigen, Inc. is developing its portfolio of clinical and pre-clinical therapies for the treatment of cancers and infectious diseases via its novel, cutting-edge GM-CSF neutralization and gene-knockout platforms. We believe that our GM-CSF neutralization and gene-editing platform technologies have the potential to reduce the inflammatory cascade associated with coronavirus infection. The company's immediate focus is to prevent or minimize the cytokine release syndrome that precedes severe lung dysfunction and ARDS in serious cases of SARS-CoV-2 infection. The company is also focused on creating next-generation combinatory gene-edited CAR-T therapies using strategies to improve efficacy while employing GM-CSF gene knockout technologies to control toxicity. In addition, the company is developing its own portfolio of proprietary first-in-class EphA3-CAR-T for various solid cancers and EMR1-CAR-T for various eosinophilic disorders. The company is also exploring the effectiveness of its GM-CSF neutralization technologies (either through the use of lenzilumab as a neutralizing antibody or through GM-CSF gene knockout) in combination with other CAR-T, bispecific or natural killer (NK) T cell engaging immunotherapy treatments to break the efficacy/toxicity linkage, including to prevent and/or treat graft-versus-host disease (GvHD) in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Additionally, Humanigen and Kite, a Gilead Company, are evaluating lenzilumab as sequenced therapy with Yescarta^® (axicabtagene ciloleucel) in patients with relapsed or refractory large B-cell lymphoma in a clinical collaboration. For more information, visit www.humanigen.com.

Forward-Looking Statements
This release contains forward-looking statements. Forward-looking statements reflect management's current knowledge, assumptions, judgment and expectations regarding future performance or events. Although management believes that the expectations reflected in such statements are reasonable, they give no assurance that such expectations will prove to be correct and you should be aware that actual events or results may differ materially from those contained in the forward-looking statements. Words such as "will," "expect," "intend," "plan," "potential," "possible," "goals," "accelerate," "continue," and similar expressions identify forward-looking statements, including, without limitation, statements regarding our expectations for the Phase 3 study and the potential future development of lenzilumab, our pathway to our intended submission for, and potential receipt of, an Emergency Use Authorization and potential subsequent BLA from FDA, and statements regarding the potential for lenzilumab to be used to prevent or treat GvHD and, as sequenced therapy with Kite's Yescarta, in CAR-T therapies. Forward-looking statements are subject to a number of risks and uncertainties including, but not limited to, the risks inherent in our lack of profitability; our dependence on partners to further the development of our product candidates; the costs associated with CMC work and the uncertainties inherent in the development and launch of any new pharmaceutical product; the outcome of pending or future litigation; and the various risks and uncertainties described in the "Risk Factors" sections and elsewhere in the Company's periodic and other filings with the Securities and Exchange Commission.

All forward-looking statements are expressly qualified in their entirety by this cautionary notice. You should not place undue reliance on any forward-looking statements, which speak only as of the date of this release. We undertake no obligation to revise or update any forward-looking statements made in this press release to reflect events or circumstances after the date hereof or to reflect new information or the occurrence of unanticipated events, except as required by law.

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Victoria Meissner, MD
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