Regenerative medicine company Cynata Therapeutics has announced that the US Food and Drug Administration (FDA) has given Orphan Drug Designation to CYP-001, its treatment for acute graft versus host disease (GvHD).
CY-001 is Cynata’s lead mesenchymal stem cell (MSC) candidate, created using the company’s Cymerus platform manufacturing technology.
An orphan drug is characterised as a therapeutic agent used for the prevention, diagnosis or treatment of a rare disease, defined as a condition that affects less than 200,000 people in the US.
Under its new designation, the drug will be eligible for a seven-year period of marketing exclusivity, tax credits from half of the clinical research costs, and FDA fee waivers, taking it a step closer to cost-effective commercialisation in the US.
GvHD occurs following procedures such as a bone marrow transplant, when a donor’s immune cells attack the transplant recipient. Currently the only approved treatment for the condition is corticosteroid therapy, though this is only effective in around 50% of patients. If steroid treatment fails to improve symptoms, patients are said to have steroid-resistant GvHD. These patients have mortality rates in excess of 90%.
Cynata has developed its treatment for patients with steroid-resistant acute GvHD and recently announced positive results from the first cohort of patients in an ongoing Phase I trial of CYP-001. So far, no adverse side effects have been seen in patients.
The first cohort, Cohort A, enrolled eight patients who were administered with a lower dose level of the drug. The overall survival by Day 100 was 87.5%, while the overall response rate by Day 100 was 100%, with all eight participants showing an improvement in the severity of GvHD by at least one grade compared to baseline. The Complete Response rate by Day 100 was 50% (GvHD signs/symptoms completely resolved in four out of eight patients). Enrolment for the second, higher-dose cohort is currently underway.
“We are delighted that the FDA has seen fit to grant Orphan Drug Designation to CYP-001, in recognition of the potential of this product to address the substantial unmet need associated with GvHD,” Cynata Vice President Dr Kilian Kelly said.
“This follows on from our successful pre-IND meeting with the FDA last year, and we look forward to building our productive relationship with the FDA over the coming years.”
Cynata’s Cymerus technology seeks to enable MSC production at a commercial scale, something which current methods do not achieve. Using induced pluripotent stem cells (iPSCs), it produces MSC precursor mesenchymoangioblast (MCA), which allows for a MSC source independent of donor limitations and an ‘off-the-shelf’ stem cell platform for therapeutic product use.
The field of regenerative medicine offers an unprecedented possibility to treat conditions for which there are currently no cures, such as acute myeloid leukaemia, HIV infections and age-related macular degeneration. High hopes around stem cell therapy mean many companies are eager to propel candidates through clinical trials despite uncertainties over their efficacy and safety. As regulatory bodies such as the FDA have less control over them than traditional drug-based treatments, certain companies have had the chance to develop and sell unregulated therapies.
As a result, the field has come under scrutiny in recent years, leading the FDA to tighten regulations on regenerative medicine advanced therapies (RMATs).
“With all of the medical potential, also comes novelty and uncertainty as this field matures,” said FDA commissioner Scott Gottlieb in an August 2017.
“There are a small number of unscrupulous actors who have seized on the clinical promise of regenerative medicine, while exploiting the uncertainty, in order to make deceptive, and sometimes corrupt, assurances to patients based on unproven and, in some cases, dangerously dubious products…This puts the entire field at risk.”
The agency has started sending warning letters to companies it perceives as not complying with safety regulations before marketing their medications, in addition to enforcing its new guidelines for the approval process of RMATs.
These guidelines allow the sale of stem cell-derived products without premarket approval only if they are minimally altered and used for the same purpose in both donor and host. Under these, circumstances, their regulation is limited to the prevention of communicable disease transmission. Products that do not fall under this designation, however, are classed as drugs, biologics or devices.