For the Record

sellison23
5 hours ago
2 min read

We got an email that asks, “How is your levamisole HCl different from OTC levamisole?” She asked after her horse go worse with OTC treatment. She is now enrolled into our pilot efficacy trial to document the laboratory differences. Sadly, she is aware of the clinical differences.

There are no licensed treatments for PNE. There were no ongoing studies to develop diagnostics or treatments for PNE. The first step was developing testing to identify the disease proposed for treatment, PNE. The diagnosis of PNE is difficult. PNE cannot be diagnosed and treated by lay persons. Pathogenes determined there was a need for treatment by developing tests to support a diagnosis of PNE. And then conducted preliminary studies to identify viable drug candidates base on safety, effectiveness, and manufacturing ability. The first step was to develop a safe and stable formulation that was is done through expensive formulation studies by finding a manufacturing facility to manufacture the formulation under cGMP conditions. Pathogenes opened an INAD file. That required studies to show the drug is safe for the animal species for which it is intended, studies to prove the drug works for its intended use under normal conditions, prove that the residues do not harm people or the environment, and data to show the dugs quality, purity, and potency are consistent from batch to batch. With each batch manufactured stability is conducted quarterly to make sure the drug remains viable. The stability testing ensures there are no substances that are toxic to the species receiving the drug. Each dose is tracked and if there are adverse events the incident is reported.

These steps are required because a drug for one species cannot be used for another due to fundamental difference in physiology, metabolism, and the regulatory approval process. A medication proven safe in effective for one animal can be ineffective, toxic, or even fatal to another. For example, ruminants metabolism is drastically different from a horse. Ruminants can take phosphate formulations while these formulations induce colic in horses.

Veterinarians that fully understand the pharmacokinetics can sometimes prescribe a drug of “off-label” use it is only done under specific, legally defined circumstances. This practice requires a valid veterinarian-client-patient relationship and is prohibited for certain drugs and uses such as in animal feed. If this had been a viable path, Pathogenes would have taken it.

The path to license an equine drug and complete the IND sections of the application are what distinguish my science from hit-or-miss therapies. As you now know giving compounded formulations did not keep your horse from clinical decline. Modifying our recommendations did not avert your horse's development of vaccine-induced PNE. We are sorry and hope there a path to recovery for your horse.