Humans have looked to the animal kingdom for inspiration on new medicines for centuries. But even so, it has only been in recent years that scientists have started to intensively explore the healing powers of venom. The toxins produced by ticks, scorpions, snakes, spiders and animals like these are now being studied as the basis of treatments for a wide range of diseases.
A recently published book by Christie Wilcox, Venomous: How Earth's Deadliest Creatures Mastered Biochemistry, profiles some of these efforts, citing a dizzying array of research. These include, for example, the use of scorpion venom as a potential treatment for children's brain tumors; sea-anemone venom for autoimmune disorders; tarantula venom for muscular dystrophy; and centipede venom for pain.
‘Scorpion venom could be used as a potential treatment for children's brain tumors; sea-anemone venom for autoimmune disorders; and centipede venom for pain.’
According to the book, the bodily mechanisms that venoms derail often turn out to be the same ones doctors need to manipulate to treat disease. These naturally occurring substances already do what human-made drugs do: target and modulate key molecules in cells, by controlling the dosage or slightly altering the chemical composition, scientists can turn toxins into treatments, the book reports.
As the Chief Executive Officer of Akari Therapeutics, Gur Roshwalb, has a special interest in this exciting area of research-specifically, the disease-treating potential of the saliva of the Ornithodoros moubata tick.
What's so special about ticks? A typical blood-sucking parasite, like a mosquito, doesn't care what happens to the host. If a mosquito bites and then flies away and a big, itchy welt is left, the mosquito couldn't care less. Ticks, however, are very different-because the tick takes a blood meal from its host for anywhere from 12 hours to two weeks, depending on the tick. In order to stay on the host for that long, somehow the tick has to be suppressing the host's local immune system so that the host doesn't respond.
In studying what makes this phenomenon possible, Akari's Chief Scientific Officer, Miles Nunn, identified a small protein called Coversin. Coversin is capable of inhibiting the action of a protein called C5, whose variants play a key role in a component of the immune system called the complement system. Ordinarily, the complement system helps disable and clear out foreign invaders and unwanted cells, but when C5's variants are produced in unregulated numbers, the result can trigger life-threatening inflammatory and autoimmune conditions.
An FDA-approved C5 inhibitor, the antibody Soliris (eculizumab), has been on the market since 2007. However, concerns have been raised regarding its cost and the need for intravenous administration at two-week intervals. Given by subcutaneous injection, Coversin makes once-daily self-administration possible and avoids IV infusion altogether.
Akari's initial clinical targets for Coversin are the rare diseases paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS) and Guillain Barre syndrome (GBS). Because of the route of administration, Akari anticipates Coversin being a first-line therapy. Beginning in February 2016, a PNH patient has been treated with Coversin with good response and a Phase II study has been initiated; the company also plans to initiate a Phase II study in aHUS in late 2016 and a Phase II study in GBS patients in early 2017.
Inspired by a lowly tick-and its immune system-suppressing saliva-Akari has joined the ranks of pioneers in turning the animal kingdom's age-old natural defenses into what could be tomorrow's medicines.