The BioTime subsidiary, Asterias, has received FDA approval for a combined Phase I/IIa clinical trial of OPC1 for treating spinal cord injury.
BioTime (BTX) and Asterias (ASTY) have picked up the portfolio of the former Geron clinical trial using oligodendrocyte precursor cells (OPC). Asterias also acquired a second element from Geron in the form of a lung cancer treatment based on stem cells that sounds quite intriguing.
To learn more about this exciting news I interviewed Jane Lebkowski, President of Research and Development at Asterias.
1. What are the most important things for the stem cell community to know about Asterias getting the FDA approval to move forward with this Phase 1/2a trial?
In the first clinical trial by Geron, safety was established in patients with thoracic spinal cord injury. Now, with this current FDA clearance and the new clinical protocol, we will test AST-OPC1 in a different patient population, those patients with complete cervical spinal cord injuries. We think this population will be the first target for registration trials for AST-OPC1. Patients with cervical injuries have more extensive paralysis involving both the lower and upper limbs. Because of both the anatomy of spinal cord in the cervical spinal cord region and superior ways to assess restoration of upper body movement, we believe testing of AST-OPC1 in this patient population will provide a better opportunity to assess potential clinical benefit of the cells.
Another important point of the new trial is that will test escalating doses of AST-OPC1. The first clinical trial performed by Geron tested a single low dose of the cells. In the new Phase 1/2a trial, we will escalate doses into the range where we feel we can see potential clinical activity.
2. What are the doses in the new trial versus the original one?
Lebkowski: The dose used in the Geron trial was 2 million cells. The new trial will start with a dose of 2 million cells in the first cohort and then escalate to doses of 10 and 20 million cells in cohorts 2 and 3.
3. The patients that originally received OPC1 when Geron was starting things have now been followed for a relatively long time. How are they doing?
Lebkowski: There have been no safety problems observed in these patients that were associated with the cells, injection of the cells, or immunosuppression used in the first clinical trial. We haven’t seen measurable neurological improvements in the patients, however these patients were administered only a low dose of cells. Importantly, there were no immune responses observed which targeted the cells. By MRI, there were indications of tissue sparing effects (reduced cavitation) in four out of the five patients in the original trial.
The device and procedure used to administer the cells in cervical spinal cord injury patients are essentially the same as those used in the first trial in thoracic injury patients.
When the product was owned by Geron, it was referred to as “GRNOPC1”. It is now called “AST-OPC1” to reflect its new owner, Asterias Biotherapeutics.
4. What does the involvement of CIRM mean for the whole process?
Lebkowski: CIRM will be helping to co-fund this new clinical trial. This funding can now be activated with the FDA clearance.
5. What will the time course be like for this trial?
Lebkowski: We plan to start the trial in early 2015 with data becoming available as the trial progresses through the cohorts.
6. In a broad sense, what does this clearance and the trial mean?
Lebkowski: Although the first trial was small, a good safety profile was established enabling more advanced testing of AST-OPC1 in clinical trials where both safety and efficacy can be potentially measured. The clearance also shows more broadly that human embryonic stem cell based therapies are progressing in their development. The field is advancing beyond the feasibility stage now.
7. Can you tell us briefly about Asterias’ lung cancer program?
Lebkowski: A second Asterias product is AST-VAC2, which are human embryonic stem cell derived dendritic cells. These cells are modified to express telomerase, a protein typically expressed in cancer cells. The aim is to use these telomerase expressing dendritic cells to stimulate immune responses against cancer cells. We are now preparing for clinical trials with this product.