Humanigen Announces Review of Lenzilumab Phase 3 Study in COVID-19 by Data Safety Monitoring Board

• Independent data safety monitoring board (DSMB) unanimously recommends trial continuation without modification after conducting pre-specified interim analysis for safety, futility, sample size and power
• Enrollment target of 300 patients expected to be completed this month

BURLINGAME, Calif.--(BUSINESS WIRE)--Humanigen, Inc., (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 its Phase 3 registration trial of lenzilumab in patients with COVID-19 was unanimously recommended for continuation without modification by an independent DSMB after a planned interim analysis.

The DSMB, composed of independent subject matter experts, conducted a pre-specified interim analysis after 50% of the expected recoveries were captured in the trial database. The DSMB assessed the Phase 3 trial data for safety, futility, sample size and power assumptions. After completing their analysis, the DSMB unanimously recommended that the trial continue according to the existing trial protocol without modification.

“This unanimous recommendation by the independent DSMB is encouraging and marks another major milestone for Humanigen as we progress towards a potential EUA for lenzilumab in COVID-19,” said Cameron Durrant, MD, MBA, chief executive officer of Humanigen. “We consider the decision to continue according to the existing protocol as a signal that the trial is progressing to plan."

Humanigen expects to complete the targeted enrollment of 300 patients this month with topline data available in the fourth quarter.

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 Phase 3 potential registration study can be found at clinicaltrials.gov using ClinicalTrials.gov 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 in combination 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 to minimize or reduce the severity of lung dysfunction associated with severe and critical COVID-19 infections or to receive an Emergency Use Authorization from, be approved by, FDA for such use or to help CAR-T reach its full potential or to deliver benefit in preventing GvHD. 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 and need for additional capital to conduct the Phase 3 study and grow our business; our dependence on partners to further the development of our product candidates; 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.

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