New funding to develop sight-saving drug

A potential eye drop treatment for wet age-related macular degeneration based on chemical compounds developed at UNSW has received a funding boost, with UK-based biopharmaceutical company Exonate raising nearly $2.56 million from investors.

Exonate is a spin-off company from the University of Nottingham founded on a collaboration between Associate Professor Jonathan Morris in the UNSW School of Chemistry and Professor David Bates at the University of Nottingham.

Professor Bates leads the biological research on the compounds using biological assays and disease models, while Associate Professor Morris leads the Medicinal Chemistry arm of this company. So far, the focus of the treatments has been for macular degeneration.

With the new injection of capital, announced at the end of November, Exonate intends to further refine the small molecule drugs, continue biological testing to take the treatment closer to clinical trials, and expand the applications of the compound to other diseases including cancer, pain and neuropathy.

In this round, Exonate attracted funding from new investors including Australian venture fund Uniseed. It also received continued support from the University of Nottingham and Angel investments, which are pooled funds from individuals and entities.

Wet macular degeneration affects 30 million patients worldwide and is caused by excessive growth of blood vessels in the eye that leads to scarring, ultimately causing deterioration of eyesight.

The excessive growth of blood vessels is due to the presence of vascular endothelial growth factor, or VEGF, which is the body’s response to the initial damage to the eye.

Existing therapies for macular degeneration aim to deplete VEGF protein using antibodies, which need to be regularly injected directly into the eye. A major disadvantage of this treatment – beside the frightening thought of eye injections – is that the eye’s ability to heal is impaired because VEGF also plays an important role in maintaining the endothelial cells lining the back of the eye.

The VEGF gene gives rise to two similar proteins, one promoting blood vessel growth called VEGF-A, and one that does not called VEGF-B. Exonate’s compounds target a switch called SRPK1 kinase which controls the splicing factor that determines which protein variant is made.

The compounds developed in the UNSW laboratories of Associate Professor Morris selectively inhibit overgrowth of blood vessels, while keeping endothelial cells healthy.

“If you block SRPK1 kinase, you will block the formation of blood vessels,” says Morris. “This is the first potent small molecule that can regulate alternate splicing.”

Exonate’s compounds are also readily absorbed through the many different layers of the eye to get to the back, without the need for an injection into the eye. The new funding boost will help to formulate the treatment for administration as an eye drop.