Asterias Provides 24 Month Cohort 2 Update for its OPC1 Phase 1/2a Clinical Trial in Severe Spinal Cord Injury

FREMONT, Calif., Sept. 12, 2018 (GLOBE NEWSWIRE) -- Asterias Biotherapeutics, Inc. (NYSE American: AST), a biotechnology company dedicated to developing cell-based therapeutics to treat neurological conditions associated with demyelination and cellular immunotherapies to treat cancer, today provided additional data from the Company’s ongoing Phase 1/2a SCiStar study designed to evaluate the safety and potential efficacy of OPC1 in the treatment of severe cervical spinal cord injury. All 6 subjects from Cohort 2 in the SCiStar study have now completed a 24-month follow-up as part of the study’s long-term follow-up protocol and each subject either retained the motor function recovery seen through 12 months or saw further motor function recovery from 12 to 24 months.

“While the primary endpoint for the SCiStar trial was 12 months, we are further encouraged by this additional follow-up data that shows both durable engraftment and motor function recovery being maintained or improved upon at 24 months,” commented Ed Wirth, Chief Medical Officer.  “We believe the primary goal of SCiStar, which was to observe the safety of OPC1 in cervical spinal cord injury patients and to accumulate data related to important factors such as optimal dosing levels, the immunosuppression regimen, engraftment of the cells, and rates of motor recovery observed among different study subpopulations, have been successfully achieved and increases our confidence as we prepare to meet the FDA later this year to discuss the next trial design.”

Below are a summary of key findings at 24 months for the Cohort 2 subjects:

  • Positive Safety Profile – MRI scans at 24 months post-injection of OPC1 has shown no evidence of adverse changes in any of the Cohort 2 subjects treated with OPC1.  Additionally, Asterias has dosed 25 subjects with OPC1 in the SCiStar study and a total of 30 subjects including the five subjects from a previous Phase 1 safety trial in thoracic spinal cord injury who have been followed for as long as seven years.  To date, there have been no serious adverse events (SAEs) related to the OPC1 cells. 
     
  • Cell Engraftment – 100% (6/6) of Cohort 2 subjects have magnetic resonance imaging (MRI) scans at 24 months consistent with the formation of a tissue matrix at the injury site, which is encouraging evidence that OPC1 cells have engrafted at the injury site and helped to prevent cavitation.  The MRI results provide supportive evidence that OPC1 cells have durably engrafted at the injury site and helped to prevent cavitation.  Cavitation is a destructive process that occurs within the spinal cord following spinal cord injuries, and typically results in permanent loss of motor and sensory function. Additionally, a patient with cavitation can develop a condition known as syringomyelia, which results in additional neurological and functional damage to the patient and can result in chronic pain.
     
  • Improved Motor Function – At 24 months, 100% (6/6) of Cohort 2 subjects have recovered at least one motor level on at least one side. At 24 months, 83% (5/6) of these subjects have recovered two or more motor levels on at least one side, compared to 67% (4/6) at 12 months after administration of the OPC1 cells.  At 24 months, the average improvement in upper extremity motor function for Cohort 2 subjects was 13.0 points, compared to 12.3 points at 12 months after administration of the OPC1 cells. At 24 months, one subject had recovered two motor levels bilaterally and another subject had recovered three motor levels on one side.*

    *One subject had recently underwent an elective surgery that restrained his ability to fully use one of the muscle groups evaluated during his 24 month follow-up and thus this muscle group was rated as not testable.  The subject had otherwise retained the motor function recovery seen through 12 months for all muscle groups that could be evaluated during the 24 month follow-up.  For purposes of determining the Cohort’s average improvement in upper extremity motor function at 24 months this subject’s 12 month score was used for the muscle group that was not testable.

OPC1 Therapeutic Platform

OPC1, an oligodendrocyte progenitor cell population derived from human embryonic stem cells, has been shown in preclinical testing in animals and in vitro to have three potentially reparative functions that address the complex pathologies observed in demyelination disorders, such as spinal cord injury and multiple neurodegenerative diseases, including multiple sclerosis and white matter stroke. These potential reparative functions of OPC1 include the production of neurotrophic factors, the stimulation of vascularization, and the induction of remyelination of denuded axons, all of which are critical for survival and regrowth of—and conduction of nerve impulses through—axons at the injury site.   

Each year in the United States, more than 17,000 people suffer a severe, debilitating spinal cord injury. As of 2016, the National Spinal Cord Injury Statistical Center reported that approximately 4,500 of these new spinal cord injuries annually in the U.S. are AIS-A, AIS-B, or AIS-C patients with C-4 to C-7 spinal cord injuries (https://www.nscisc.uab.edu/). These injuries can be devastating to quality of life and ability to function independently. Lifetime healthcare costs for these patients can often approach $5 million. Improvements in arm, hand, and finger functional capabilities in these patients can result in meaningfully lower healthcare costs, significant improvements in quality of life, greater ability to engage in activities of daily living, and increased independence. 

Anticipated Data Readouts for the SCiStar Study

Asterias has completed enrollment and dosing in all five of its planned SCiStar study cohorts. The Company intends to report 12 month results for the entire SCiStar study in the first quarter of 2019. 

About Asterias Biotherapeutics

Asterias Biotherapeutics, Inc. is a biotechnology company dedicated to developing cell-based therapeutics to treat neurological conditions associated with demyelination and cellular immunotherapies to treat cancer. Asterias is presently focused on advancing two clinical-stage programs which have the potential to address areas of very high unmet medical need in the fields of neurology and oncology. OPC1 (oligodendrocyte progenitor cells) is currently in a Phase 1/2a dose escalation clinical trial in spinal cord injury. VAC2 (antigen-presenting allogeneic dendritic cells) is an allogeneic cancer immunotherapy. The Company's research partner, Cancer Research UK, has commenced a first-in-human clinical trial of VAC2 in non-small cell lung cancer.  Asterias is also sponsoring pre-clinical work in two conditions with a demyelinating component: Multiple Sclerosis and White Matter Stroke, and is evaluating other cancer indications where its immunotherapy platform could provide therapeutic benefit. Additional information about Asterias can be found at www.asteriasbiotherapeutics.com.

About OPC1

OPC1, an oligodendrocyte progenitor cell population derived from human embryonic stem cells, has been shown in preclinical testing in animals and in vitro to have three potentially reparative functions that address the complex pathologies observed in demyelination disorders, such as spinal cord injuries, and multiple neurodegenerative diseases, including multiple sclerosis and white matter stroke. These potential reparative functions of OPC1 include the production of neurotrophic factors, the stimulation of vascularization, and the induction of remyelination of denuded axons, all of which are critical for survival and regrowth of—and conduction of nerve impulses through—axons at the injury site.   

About the SCiStar Trial

The SCiStar trial is an open-label, single-arm trial testing three sequential escalating doses of OPC1 administered at up to 20 million OPC1 cells in 25 subjects with subacute motor complete (AIS-A or AIS-B) cervical (C-4 to C-7) SCI. These individuals have essentially lost all movement below their injury site and experience severe paralysis of the upper and lower limbs. AIS-A subjects have lost all motor and sensory function below their injury site, while AIS-B subjects have lost all motor function but may have retained some minimal sensory function below their injury site. OPC1 is administered 21 to 42 days post-injury. Subjects will be followed by neurological exams and imaging procedures to assess the safety and activity of the product.

The SCiStar study consists of five cohorts:

    Cohort Injury Type; OPC1 Dose # of Subjects
    Cohort 1 AIS-A; 2M OPC1 cells
(low dose for initial safety evaluation)
3
    Cohort 2 AIS-A; 10M OPC1 cells 6
    Cohort 3 AIS-A; 20M OPC1 cells* 6
    Cohort 4 AIS-B; 10M OPC1 cells 6
    Cohort 5 AIS-B; 20M OPC1 cells* 4
    Total   25
*One subject from Cohort 3 and one subject from Cohort 5 were administered 10 million cells.

Asterias has received a Strategic Partnerships Award grant from the California Institute for Regenerative Medicine, which provided $14.3 million of non-dilutive funding for the Phase 1/2a clinical trial and other product development activities for OPC1.

Additional information on the Phase 1/2a trial, including trial sites, can be found at www.clinicaltrials.gov, using Identifier NCT02302157, and at the SCiStar Study Website (www.SCiStar-study.com). 

FORWARD-LOOKING STATEMENTS
Statements pertaining to future financial and/or operating and/or clinical research results, future growth in research, technology, clinical development, and potential opportunities for Asterias, along with other statements about the future expectations, beliefs, goals, plans, or prospects expressed by management constitute forward-looking statements. Any statements that are not historical fact (including, but not limited to statements that contain words such as "will," "believes," "plans," "anticipates," "expects," "estimates") should also be considered to be forward-looking statements. Forward-looking statements involve risks and uncertainties, including, without limitation, risks inherent in the development and/or commercialization of potential products, uncertainty in the results of clinical trials or regulatory approvals, need and ability to obtain future capital, and maintenance of intellectual property rights. Actual results may differ materially from the results anticipated in these forward-looking statements and as such should be evaluated together with the many uncertainties that affect the businesses of Asterias, particularly those mentioned in the cautionary statements found in Asterias' filings with the Securities and Exchange Commission. Asterias disclaims any intent or obligation to update these forward-looking statements.

Contacts:
Investor Relations
(510) 456-3892
InvestorRelations@asteriasbio.com
or
EVC Group, Inc.
Michael Polyviou/Todd Kehrli
(732) 232-6914
mpolyviou@evcgroup.com; tkehrli@evcgroup.com

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