Humanigen Announces Preliminary Results From Ifabotuzumab Phase I Study Accepted for Presentation at the American Association for Cancer Research (AACR) Annual Meeting

• Study Demonstrates that Dosing with Ifabotuzumab Results in Rapid, Specific and Reproducible Targeting of the Tumor Microenvironment in Patients with Glioblastoma Multiforme (GBM)
• Imaging Changes Suggest Modulation of the Tumor Vasculature by Ifabotuzumab without Normal Tissue Uptake
• Provides Evidence that Targeting EphA3 is a Viable Strategy for the Treatment of Solid Tumors

BURLINGAME, Calif., April 01, 2019 (GLOBE NEWSWIRE) -- Humanigen, Inc., (OTCQB: HGEN) (“Humanigen”), a biopharmaceutical company developing its portfolio of Humaneered® monoclonal antibodies focused on CAR-T optimization and immuno-oncology announced today that preliminary results from an ongoing phase I bioimaging study of the company’s proprietary anti-EphA3 monoclonal antibody, ifabotuzumab (formerly known as KB004), in patients with recurrent GBM have been accepted for presentation at the 2019 annual meeting of the AACR being held in Atlanta, GA, March 29 – April 3, 2019.  The study demonstrates that dosing with ifabotuzumab results in rapid, specific and reproducible targeting of the tumor microenvironment without normal tissue uptake and suggests a direct impact of ifabotuzumab on tumor vasculature, providing evidence that targeting EphA3 expressing tumor neovasculature is a viable therapeutic strategy for solid tumors (abstract available at ).

The research, led by Drs. Andrew Scott and Hui Gan from the Olivia Newton-John Cancer Research Institute in Heidelberg, Victoria, Australia, used radiolabelled ifabotuzumab followed by sequential positron emission tomography (PET) imaging to determine biodistribution, frequency of in situ EphA3 expression and quantitative tumor uptake of ifabotuzumab.  Patients were subsequently enrolled into one of three cohorts evaluating escalating doses of ifabotuzumab administered weekly, allowing for an assessment of receptor occupancy, response rate and overall survival.  The preliminary results include data from four patients who have been enrolled to date.  PET/computed tomography (CT) imaging showed that ifabotuzumab is effectively delivered across the blood-tumor barrier and accumulates specifically at the tumor site in all patients treated to date with no observed normal brain tissue uptake.  Magnetic resonance imaging (MRI) scans showed predominant T2/FLAIR changes, consistent with the treatment effect of ifabotuzumab on tumor vasculature.  Treatment emergent adverse events were manageable with supportive measures.

The preliminary results of this phase I trial using Humaneered^® ifabotuzumab are consistent with the preclinical study recently published in the journal ‘Cancers’ by doctors Bryan Day & Andrew Boyd from the Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute in Brisbane, Australia, in which they used the murine predecessor antibody to ifabotuzumab and showed that the EphA3 receptor is an attractive tumor-specific target for GBM and other solid tumors (available online at ).  EphA3 is a tumor restricted antigen expressed in 100% of the tumor vasculature of GBM.  It is also highly expressed in the tumor vasculature and tumor stroma of a number of solid tumors including colon, lung, kidney, bladder, and melanoma.

“By specifically targeting the tumor stem cells, stromal cells and neovasculature, we believe ifabotuzumab has the potential to emerge as a next-generation oncology therapy for a range of solid tumors,” said Dr. Cameron Durrant, CEO of Humanigen.  With drug provided by Humanigen and grant funding from Cure Brain Cancer Foundation (Australia), this study is in part motivated by reports of the positive results of antibody-drug conjugate therapies in the treatment of GBM, including depatuxizumab mafodotin which is in Phase 3 development by Abbvie. “Ifabotuzumab is being developed by the leading experts in the space, who played a critical role in the discovery and development of depatuxizumab,” continued Dr. Durrant. 

About Humanigen, Inc. 

Humanigen, Inc. is developing its portfolio of Humaneered® monoclonal antibodies to address cutting-edge CAR-T optimization and oncology treatments advancing safer, better, and more effective cancer therapies.  Derived from the company’s Humaneered® platform, lenzilumab and ifabotuzumab, and HGEN005 are monoclonal antibodies with first-in-class mechanisms.  Lenzilumab, which targets GM-CSF, is in development as a potential biologic therapy to make CAR-T therapy safer and more effective, as well as a potential treatment for hematologic cancers.  Ifabotuzumab, which targets the Eph type-A receptor 3 (EphA3), is being explored as a potential treatment for glioblastoma multiforme (GBM) and a range of solid tumors, both as an optimized naked antibody and as part of an antibody-drug conjugate, as well as a backbone for a novel CAR-T construct, and a bispecific antibody platform. HGEN005 which selectively targets the eosinophil receptor EMR1 is being explored as a potential treatment for a range of eosinophilic diseases including eosinophilic leukemia both as an optimized naked antibody and as the backbone for a novel CAR-T construct.  For more information, visit 

About the Olivia Newton-John Cancer Research Institute

The Olivia Newton-John Cancer Research Institute is a leader in the development of experimental and breakthrough cancer treatments. We investigate and develop treatments for cancers of the breast, bowel, lung, melanoma, prostate, liver, gastrointestinal tract and brain. Our researchers and clinicians are running more than 200 clinical trials, giving patients access to potential new treatments including immunotherapies and personalised medicine. For more information visit

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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 future development of ifabotuzumab in solid tumors, lenzilumab to help CAR-T therapy reach its full potential or HGEN005 in eosinophilic diseases. Forward-looking statements are subject to a number of risks and uncertainties including, but not limited to, the risks inherent in Black Horse Capital and its affiliates owning more than 50% of our outstanding common stock, including their ability to control the company; our lack of profitability and the need for additional capital to operate our business as a going concern; 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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