Our NSKI products are designed to be absorbed locally by inflammatory cells in the target tissue but as relatively large ‘small molecules’ they are retained by these cells, rather than passing into the general circulation. This is in direct contrast to traditional drugs, which are designed to be rapidly absorbed, to achieve therapeutic plasma levels in body tissues, and then be eliminated by the body. This means that NSKIs have the potential to produce long lasting effects at the site of the disease and with only minimal systemic bioavailability, healthy tissues in the rest of the body have only limited exposure to the chemical agent. As a result, NSKIs are expected to demonstrate excellent product safety and tolerability, both in the short-term and importantly, in the long-term, as maintenance therapies in our target diseases.
Our NSKI products targeting eye diseases are perfectly designed for localised therapy in the eye both due to their non-systemic bioavailability and their long duration of action in inflammatory cells. This is complemented by the anatomy of the eye, as it acts a natural barrier to help stop foreign substances entering the body. The eye can be broadly classified into two segments: anterior and posterior (front and back). Topical administration, mostly commonly in the form of eye drops, is employed to treat anterior segment diseases.
In dry eye disease (DED), our lead ophthalmology indication, we are able to deliver our lead NSKI compound directly to the epithelium layer of the eye, which is the site of the inflammation which occurs in the disease. Once absorbed, the slow clearance of NSKIs in local inflammatory cells is expected to provide a sustained localised effect while avoiding systemic exposure of the drug to healthy tissues in the rest of the body.
In our Phase 1/2a study, there were no safety findings, with TOP1630 shown to be safe and very well tolerated with a placebo-like profile. Importantly, this included no noticeable instillation site pain and discomfort as is frequently seen with currently marketed products.
Our NSKI products for the treatment of GI diseases exert their therapeutic effects locally in the GI tracts, and within the colon specifically, with only minimal systemic uptake to minimise their exposure to healthy tissues in the body. This has been demonstrated in our clinical studies with TOP1288 to date.
The concept of non-systemic drugs, which act within the intestinal lumen without reaching the systemic circulation, is not a new concept with products such polymeric resins available that bind or mop-up certain molecules in the gut. However, the field is evolving and second-generation approaches aim to deliver relatively non-absorbable small molecules or peptides for the treatment of a range of diseases including diabetes and various GI disorders. TopiVert is proud to be a pioneer in this exciting field.