Safi Biotherapeutics is moving manufactured red blood cells closer to U.S. clinical trials, aiming to produce units from a single donation to help patients with transfusion challenges, according to a presentation at the “Key Advances in Biotherapies” Oral Abstract Session.
In Plain English: The Clinical Takeaway
- What it is: Scientists are growing red blood cells in laboratory bioreactors instead of relying entirely on human donors.
- Why it matters: Patients who need frequent transfusions—such as those with sickle cell disease—often struggle to find compatible blood types. Manufactured cells could provide matching units.
- What comes next: The company is scaling up production and targeting human clinical trials under an investigational new drug application.
Scaling Bioreactor Production for Transfusion Medicine
Blood bankers have studied the potential of manufactured red cells to match complex antigen profiles. At the “Key Advances in Biotherapies” Oral Abstract Session, Kyle Meetze, chief operating officer of Safi Biotherapeutics Inc., outlined how his team is working to turn that concept into a clinical reality. The manufacturing process begins with hematopoietic progenitor cells sourced from mobilized peripheral blood or cord blood. Researchers expand these cells and drive their differentiation into red blood cells over approximately 21 days, with induced pluripotent stem cells serving as a potential future source.
The resulting product has a defined antigen profile, is free of pathogens and immune cells, and consists of uniformly young red blood cells. Crucially, the donor’s antigen profile carries through the manufacturing process. To increase production, Safi focuses on cell density rather than simply building bigger bioreactors. The company currently achieves cell densities of approximately 100 million cells per milliliter, yielding one to two units from a 10-liter bioreactor. The goal is to reach 500 million cells per milliliter and eventually produce one to two units per liter of bioreactor volume.
Evaluating Cellular Deformability and Cryopreservation
Laboratory analysis shows that the manufactured cells are predominantly reticulocytes, with approximately 85% achieving enucleation. The final product is filtered to remove cells that retain their nuclei. When compared directly against donor red blood cells, the manufactured alternatives exhibit similar deformability and oxygen dissociation characteristics. However, they were somewhat stiffer and contained approximately 20% more hemoglobin per cell.
Cryopreservation offers another advantage. Meetze reported that more than 80% of manufactured cells could be recovered fully functional using a method that does not require dimethyl sulfoxide or glycerol. Preclinical in vivo studies conducted with collaborators at Emory University demonstrated that refrigerated and cryopreserved manufactured cells performed broadly comparably to fresh donor cells.
| Parameter | Manufactured Red Blood Cells | Conventional Donor Red Blood Cells |
|---|---|---|
| Cell Maturity | Predominantly reticulocytes (85% enucleation) | Not specified |
| Hemoglobin Content | Approximately 20% higher per cell | Not specified |
| Storage Method | Cryopreservation (no DMSO/glycerol) | Not specified |
| Antigen Profile | Defined and consistent | Not specified |
Addressing Alloimmunization in Chronic Transfusion Patients
Patients requiring repeated blood transfusions frequently encounter alloimmunization. Manufactured red blood cells could help by making antigen-matched units available in larger quantities and maintaining a consistent antigen profile across transfusions. Individuals living with sickle cell disease represent a population that could benefit. Furthermore, cord blood-derived cells could offer a source of red blood cells for neonatal transfusions, while manufactured reagent red blood cells present a potential near-term application.
Translating this biotechnology requires overcoming economic and regulatory hurdles. Safi’s model targets parity with donor blood, though that projection has not yet been validated in practice. Primary cost drivers include cell density, culture media, expensive cytokines and growth factors, and the process of recovering cells after manufacturing. Additionally, clinical studies will be needed to establish the effective clinical dose, which Meetze hypothesized could be smaller than a conventional unit of packed red blood cells.
Contraindications & When to Consult a Doctor
As these biotherapies move toward human evaluation, established transfusion protocols remain the standard of care.
Safi hopes to initiate a clinical trial under an investigational new drug application in 2027. This work has received substantial funding from the Defense Health Agency. Sustaining this development path will ultimately depend on reliable sources of mobilized peripheral blood and cord blood.
References
- AABB Annual Meeting. Key Advances in Biotherapies Oral Abstract Session.
