Monepantel (MPL) is an oral aminoacetonitrile (AAD) compound that modulates the mTOR pathway, which is recognised as a key driver of cancer.  PharmAust is evaluating MPL for treatment of lymphomas and other cancers in companion animals. The overall market for veterinary medical products is more than $22 billion. Key drivers include increasing dog numbers (90 million dogs now in the US) and an increasing willingness for owners to spend more on their pets as they are considered part of the family. According to American Pet Products (2015), almost 80 percent of all dog owners have their dogs treated with drugs, compared to about 50 percent in 1998.

An estimated 6 million dogs are diagnosed with cancer in each year in the US compared to 1.7 million humans.  Many of the most common cancers in dogs (eg. Lymphoma, Osteosarcoma, Mammary) are recognised as being very similar to human cancers.  As such, dogs are increasingly recognised as excellent models for human disease. PharmAust’s strategy is to develop MPL as a novel therapy to treat common cancers in dogs and then use this information to inform and de-risk its human clinical development programme.  As MPL is already registered for use in animals we can significantly reduce the cost and time required to register a new treatment for pets.  Further, PharmAust has shown that MPL is a cost-effective, safe and potent therapy, which meets the unique combination of criteria required to generate a commercial return in the companion animal drug market.

In a Phase I trial conducted in dogs diagnosed with solid tumours, MPL was shown to be well tolerated and reported as beneficial to Quality of Life (QOL) in canines with cancer doses up to 25 mg/kg bw daily either as monotherapy or at 5 mg/kg bw in combination with carboplatin. Further, MPL dosed at 5 mg/kg bw daily in canines with “standard of care” treatment-refractory cancer effectively and significantly reduces blood levels of the cancer-specific marker p-Rbps6k.

In a Phase 2 pilot programme, dogs diagnosed with lymphoma were treated with MPL as front-line therapy with doses up to 25mg/kg/day for two weeks before transitioning to standard therapy.  Results showed that 100% of dogs diagnosed with B-cell lymphoma developed stable disease and showed evidence of tumour regression with minimal side-effects following MPL treatment. Lymphoma in dogs is very aggressive and, without treatment, the tumours are often fatal within weeks.