- The toxicology results suggest that CYT-108 is safe to administer when exposed to the systemic circulation at a highly-concentrated (10x) dose.
- The efficacy results indicate that CYT-108 has slight therapeutic effects when injected into damaged, arthritic joints.
- Taken together, the results of the preclinical study indicate that CYT-108 was generally tolerated when injected at highly concentrated doses. Moreover, results also indicated slight trends in therapeutic cartilage-protective effects when CYT-108 was administered into damaged joints. (These results need to be confirmed in a larger preclinical study and discussed with the FDA before entering Phase 1 human trials.)
- This was a key milestone on the path to approval and commercialization, and will be used to substantiate our request to enter Phase 1 human clinical trials.
- This study is the most important trial we have conducted thus far, and is a key driver of the valuation of the company!
From the lab to hospital bed
The journey to commercialization for an experimental drug is long and fraught with risk. It is no small undertaking, and only the boldest scientists and physicians attempt to translate their research into clinical therapies. As a former cancer biologist, I can attest to the incredible amount of creativity and ingenuity that is pervasive in academic institutions. Every PhD in the lab has an awesome idea on how to treat their disease of interest and may even have some data to prove it. However, there is a large discrepancy between the research generated in an academic lab (which is usually more exploratory than treatment-related) and the clinical research performed by pharmaceutical companies. The clinical viability of those academic ideas is not obvious often never translates into an FDA approved therapy. That’s where preclinical studies come into play. After an experimental drug is discovered or engineered and tested in a laboratory setting (using some petri dish-based or mouse model of the disease to see if the drug has any potential), a more involved set of experiments must be performed in large animals (which are more anatomically and physiologically similar to humans than rodents) to determine the safety, toxicity, and possible efficacy of the drug in treating the disease of interest. These experiments are preclinical and provide the FDA with enough information to determine whether the experimental drug is safe and promising enough to test in humans (Phase 1-3 clinical trials). At the end of the day, safety is paramount, and we must be certain that we are not going to harm anyone when we conduct a our first-in-human study (Phase 1 trial).
The preclinical data is in, and CYT-108 is ready for prime time!
Cytonics is on the verge of human clinical trials for its experimental drug candidate, CYT-108, a synthetic variant of the naturally-occurring A2M blood protein that has been demonstrated to reverse the effects of osteoarthritis of the joint. Preliminary preclinical data (below) demonstrates CYT-108’s efficacy in preserving the cartilage and surrounding tissues (e.g., synovial membrane) in a large animal model of post-traumatic osteoarthritis. In our preclinical study, osteoarthritis was induced by destabilizing the joints of the subjects, which induced cartilage damage and joint swelling similar to the damaging effects of osteoarthritis in humans. Regular treatments of CYT-108 (or placebo saline solution) were injected into the damaged joints along a 12-week treatment window. Pieces of the cartilage and surrounding tissues (bone, synovial membrane, meniscus) were examined to measure the cartilage-protective effects of CYT-108 and its ability to encourage joint remodeling/healing. The data below provides a snapshot of these results. In summary, administration of CYT-108 into the joint restored the damage caused by osteoarthritis to the cartilage (Fig 1) and synovial membranes (Fig 2) by ~60%! This damage was assessed using the modified OARSI scoring system, which is a grading scale that pathologists use to determine the damage to various tissues (on a microscopic level). This therapeutic trend was observed in 4 other measurements of cartilage, bone, and synovial membrane health (see slides 16-17 of the presentation)!

Figure 1. Intra-articular injection of our recombinant A2M variant, CYT-108, results in articular cartilage preservation and recovery of cartilage degradation in large animal subjects suffering from post-traumatic osteoarthritis. Histopathological macroscopic and microscopic grading (modified OARSI scoring system) of the articular cartilage in Groups 1-3 reveals that treatment with CYT-108 results in recovery of ~57% of the damage to the cartilage structure in the knee joint that occurs due to induced joint instability and cartilage damage. These results indicate that CYT-108 has therapeutic activity against the degradation of articular cartilage that results from the pathogenesis of osteoarthritis. Taken together with the toxicology and immunogenicity data (not shown), this body of preliminary preclinical data indicates that CYT-108 may be a safe, viable treatment for osteoarthritis. Error bars +/- SEM.

Figure 2. Intra-articular injection of our recombinant A2M variant, CYT-108, results in thinner, healthier synovial membranes in large animal subjects suffering from post-traumatic osteoarthritis. Histopathological microscopic grading (modified OARSI scoring system) of the synovial membranes of subjects in Groups 1-3 reveals that treatment with CYT-108 results in recovery of ~60% of the cellular thickening and cell layer accumulation of the synovial membrane that occurs due to trauma and inflammation of the knee joint. These results indicate that CYT-108 has therapeutic activity against the pathological changes in the synovial membrane that occur as a result of the pathogenesis of osteoarthritis. Taken together with the toxicology and immunogenicity data (not shown), this body of preliminary preclinical data indicates that CYT-108 may be a safe, viable treatment for osteoarthritis. Error bars +/- SEM.