Humanigen, Inc. provided the following regulatory update on lenzilumab™ for the treatment of COVID-19 in the United States, United Kingdom, and the European Union. United States: The Company met with senior staff representatives of the United States Food and Drug Administration (“FDA”) in a Type B meeting as part of the follow-up to FDA's response to the Company's Emergency Use Authorization (“EUA”) submission. Based on the FDA's written responses to the Company's pre-meeting briefing materials and verbal comments in the meeting, the Company intends to include the results from the ACTIV-5/BET-B study, if positive and confirmatory of the results generated by the Company's LIVE-AIR study, in an amendment to the previously filed submission for EUA.

ACTIV-5/BET-B has met its target enrollment and topline data from the study is expected in late first quarter or early second quarter 2022. United Kingdom: The Company received a written response from the Medicines and Healthcare products Regulatory Agency (MHRA) to the Company's submission of lenzilumab for marketing authorization and held a series of clarifying discussions with MHRA representatives. The MHRA response included several requests for further information related to clinical, manufacturing and quality processes.

The Company believes it can respond to a majority of the requests in the first quarter of 2022. Certain performance process qualification (“PPQ”) drug product batches have to be manufactured and the analytical data from these batches would need to be submitted to MHRA unless waived. This work is expected to be completed in the second quarter of 2022.

The Company also plans on including the results from ACTIV-5/BET-B, if positive and confirmatory, in the responsive MHRA submission. European Union: As a result of feedback received from representatives of the European Medicines Agency (“EMA”), the Company intends to submit a Conditional Marketing Authorization (“CMA”) for lenzilumab with an Accelerated Approval request. The Company believes EMA's requirements will be similar to MHRA and anticipates including in the CMA the same information submitted to MHRA.

The Company also plans to include the results from ACTIV-5/BET-B in the CMA.