Athersys Partner HEALIOS K.K. Completes Enrollment in the TREASURE Study of MultiStem Treatment for Ischemic Stroke

Off-the-shelf stem cell therapy has potential to enhance recovery for stroke patients

CLEVELAND–(BUSINESS WIRE)–$ATHX #Athersys–Athersys, Inc. (NASDAQ: ATHX) announced today that its partner, HEALIOS K.K. (�Healios”), has completed enrollment in its TREASURE study in Japan, evaluating MultiStem^® (invimestrocel) cell therapy treatment in patients who have suffered an ischemic stroke. The details are provided in Healios’ press release: https://ssl4.eir-parts.net/doc/4593/tdnet/2013098/00.pdf

The TREASURE study is a placebo-controlled, double-blind, phase 2/3 trial designed to confirm the efficacy and safety of MultiStem (HLCM051) in treating patients with ischemic stroke. Patients were randomized 1:1 to receive either a single intravenous infusion of HLCM051 or placebo within 18–36 hours of the onset of stroke. The primary efficacy outcome is the proportion of subjects achieving an Excellent Outcome at day 90.

“We are very excited that Healios has reached this important milestone of completing enrollment in the TREASURE trial,” commented Mr. William (B.J.) Lehmann, Jr., President, and Interim CEO of Athersys. “We believe that MultiStem has the potential to improve standard of care for patients that have suffered a stroke while also extending the treatment window, providing a potential treatment option for many more patients. We look forward to the topline results which Healios is targeting for release later this year.”

Athersys is currently conducting its MASTERS-2 study, a Phase 3, randomized, double-blind, placebo-controlled clinical trial designed to enroll 300 patients in North America, Europe and other regions who have suffered moderate to moderate-severe ischemic stroke. The MASTERS-2 study is being run under a Special Protocol Assessment (SPA) by the United States Food and Drug Administration (FDA) for the design and planned analysis. In addition, the program has received multiple regulatory designations meant to expedite approval, including Fast Track designation and Regenerative Medicine Advanced Therapy (RMAT) from the FDA. The European Medicines Device Agency (EMA), granted the program a Final Scientific Advice positive opinion establishing alignment between European and the United States regulators about the potential for approval based on the success of the MASTERS-2 study, which further expedites development.

About Ischemic Stroke

Stroke represents an area where the clinical need is particularly significant, since it is a leading cause of death and serious disability worldwide, with a substantially impaired quality of life for many stroke victims. Currently, there are nearly 17 million people who suffer a stroke globally and more than two million stroke victims each year in the United States, Europe and Japan, combined. Ischemic strokes, which represent the most common form of stroke, are caused by a blockage of blood flow in the brain that cuts off the supply of oxygen and nutrients and can result in long-term or permanent disability due to neurological damage. Unfortunately, current therapeutic options for ischemic stroke victims are limited, since the only available treatments, administration of the clot dissolving agent tPA, or “thrombolytic,” or surgical intervention to remove the clot, must be conducted within several hours of the occurrence of the stroke. As a consequence of this limited time window, only a small percentage of stroke victims are treated with the currently available therapy—most simply receive supportive or “palliative” care. The long-term costs of stroke are substantial, with many patients requiring extended hospitalization, extended physical therapy or rehabilitation (for those patients that are capable of entering such programs), and many require long-term institutional or family care.

About MultiStem® (invimestrocel)

MultiStem® cell therapy (invimestrocel) is a patented regenerative medicine product candidate in clinical development that has shown the ability to promote tissue repair and healing in a variety of ways, such as through the production of therapeutic factors in response to signals of inflammation and tissue damage. MultiStem therapy’s potential for multidimensional therapeutic impact may distinguish it from traditional biopharmaceutical therapies focused on a single mechanism of benefit. MultiStem represents a unique “off-the-shelf” stem cell product candidate that can be manufactured in a scalable manner, may be stored for years in frozen form, and is administered without tissue matching or the need for immune suppression. Based upon favorable outcome data, its novel mechanisms of action, and favorable and consistent tolerability data in clinical studies, we believe that MultiStem therapy may provide a meaningful benefit to patients, including those suffering from serious diseases and conditions with unmet medical need.

About Athersys

Athersys is a biotechnology company engaged in the discovery and development of therapeutic product candidates designed to extend and enhance the quality of human life. The Company is developing its MultiStem® cell therapy product, a patented, adult-derived “off-the-shelf” stem cell product, initially for disease indications in the neurological, inflammatory and immune, cardiovascular, and other critical care indications and has several ongoing clinical trials evaluating this potential regenerative medicine product. Athersys has forged strategic partnerships and a broad network of collaborations to further advance MultiStem cell therapy toward commercialization. More information is available at www.athersys.com. Follow Athersys on Twitter at www.twitter.com/athersys.

About Healios

Healios is Japan’s leading clinical-stage biotechnology company harnessing the potential of stem cells for regenerative medicine. It aims to offer new therapies for patients suffering from diseases without effective treatment options. Healios is a pioneer in the development of regenerative medicines in Japan, where it leverages its proprietary, gene-edited “universal donor” induced pluripotent stem cell (iPSC) platform technology to develop next-generation regenerative treatments across several domains. Healios combines its deep iPSC and gene editing expertise to make innovative engineered cell therapeutics including HLCN061, its functionally enhanced NK cell product candidate to treat solid cancer indications. Healios’ near-term pipeline includes the somatic stem cell product HLCM051 (MultiStem), which is currently being evaluated in Japan in Phase 2/3 and Phase 2 clinical trials for ischemic stroke and acute respiratory distress syndrome, respectively. Healios was established in 2011, has over 140 people in its Tokyo and Kobe operations, and has been listed on the Tokyo Stock Exchange since 2015 (TSE Mothers: 4593). https://www.healios.co.jp/en.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that involve risks and uncertainties. These forward-looking statements relate to, among other things, the expected timetable for development of our product candidates, our growth strategy, and our future financial performance, including our operations, economic performance, financial condition, prospects, and other future events. We have attempted to identify forward-looking statements by using such words as “anticipates,” “believes,” “can,” “continue,” “could,” “estimates,” “expects,” “intends,” “may,” “plans,” “potential,” “should,” “suggest,” “will,” or other similar expressions. These forward-looking statements are only predictions and are largely based on our current expectations. A number of known and unknown risks, uncertainties, and other factors could affect the accuracy of these statements. Some of the more significant known risks that we face are the risks and uncertainties inherent in the process of discovering, developing, and commercializing products that are safe and effective for use as therapeutics, including the uncertainty regarding market acceptance of our product candidates and our ability to generate revenues. The following risks and uncertainties may cause our actual results, levels of activity, performance, or achievements to differ materially from any future results, levels of activity, performance, or achievements expressed or implied by these forward-looking statements: our ability to raise capital to fund our operations, including but not limited to, the timing and nature of results from MultiStem clinical trials, including the MASTERS-2 Phase 3 clinical trial evaluating the administration of MultiStem for the treatment of ischemic stroke, and the Healios TREASURE and ONE-BRIDGE clinical trials in Japan evaluating the treatment in stroke and ARDS patients, respectively; the success of our MACOVIA clinical trial evaluating the administration of MultiStem for the treatment of COVID-19 induced ARDS, and the MATRICS-1 clinical trial being conducted with The University of Texas Health Science Center at Houston evaluating the treatment of patients with serious traumatic injuries; the impact of the COVID-19 pandemic on our ability to complete planned or ongoing clinical trials; the possibility that the COVID-19 pandemic could delay clinical site initiation, clinical trial enrollment, regulatory review and the potential receipt of regulatory approvals, payment of milestones under our license agreements and commercialization of one or more of our product candidates, if approved; the availability of product sufficient to meet commercial demand shortly following any approval, such as in the case of accelerated approval for the treatment of COVID-19 induced ARDS; the impact on our business, results of operations and financial condition from the ongoing and global COVID-19 pandemic, or any other pandemic, epidemic or outbreak of infectious disease in the United States; the possibility of delays in, adverse results of, and excessive costs of the development process; our ability to successfully initiate and complete clinical trials of our product candidates; the impact of the COVID-19 pandemic on the production capabilities of our contract manufacturing partners and our MultiStem trial supply chain; the possibility of delays, work stoppages or interruptions in manufacturing by third parties or us, such as due to material supply constraints, contamination, operational restrictions due to COVID-19 or other public health emergencies, labor constraints, regulatory issues or other factors which could negatively impact our trials and the trials of our collaborators; uncertainty regarding market acceptance of our product candidates and our ability to generate revenues, including MultiStem cell therapy for neurological, inflammatory and immune, cardiovascular and other critical care indications; changes in external market factors; changes in our industry’s overall performance; changes in our business strategy; our ability to protect and defend our intellectual property and related business operations, including the successful prosecution of our patent applications and enforcement of our patent rights, and operate our business in an environment of rapid technology and intellectual property development; our possible inability to realize commercially valuable discoveries in our collaborations with pharmaceutical and other biotechnology companies; our ability to meet milestones and earn royalties under our collaboration agreements, including the success of our collaboration with Healios; our collaborators’ ability to continue to fulfill their obligations under the terms of our collaboration agreements and generate sales related to our technologies; the success of our efforts to enter into new strategic partnerships and advance our programs, including, without limitation, in North America, Europe and Japan; our possible inability to execute our strategy due to changes in our industry or the economy generally; changes in productivity and reliability of suppliers; the success of our competitors and the emergence of new competitors; and the risks mentioned elsewhere in our Annual Report on Form 10-K for the year ended December 31, 2020 under Item 1A, “Risk Factors” and our other filings with the SEC. You should not place undue reliance on forward-looking statements contained in this press release, and we undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise

Contacts

Ivor Macleod

Chief Financial Officer

Tel: (216) 431-9900

ir@athersys.com

Karen Hunady

Director of Corporate Communications & Investor Relations

Tel: (216) 431-9900

khunady@athersys.com

David Schull

Russo Partners, LLC

Tel: (212) 845-4271 or (858) 717-2310

David.schull@russopartnersllc.com