The Australian parents pushed to the edge of bankruptcy trying to save their children.

Max Horder, 13, and his sister Mila, 12, have a rare hereditary condition called lysosomal storage disease.

The incurable disease is damaging their bones, affecting both growth and mobility. It is also causing their family financial ruin.

The drug that could offer greater endurance and pain relief is Vimizim but its affordability has placed the family with devastating options.

"We know that it's not a cure but know that it's going to help us a lot," Mila said.

"People who can't walk anymore, they're able to walk now."

The cost of the drug has been estimated to sit at almost half a million dollars per child on an annual basis.

The family requested to add the drug to the Pharmaceuticals Benefits Scheme in order to gain some much needed government subsidy but were rejected.

"Do we matter - does our pain, does how we feel matter?" Mila said.

Mother Luba Horder told The Project that her choices are lobbying the government to reconsider their decision or seeking compassionate funding from the drug company.

"Lobbying to get access to treatment just means that I can't manage their symptoms," Horder said.

"So not giving them this treatment is more or less like sentencing them to a life of pain and ultimately, death."

"Because it will dictate their last breath."

Carrie Bickmore expressed her deep sympathy with the family before sharing more news of their unfortunate future.

"We have heard from the drug company today and at this stage it's looking unlikely that they're willing to do the compassionate thing." Bickmore said.

"They're thinking the emphasis should be on the government - the government should be carrying the load here."

There are only 21 known cases of the disease in Australia.

Speaking to The Daily Telegraph, Horder shared how those costs translated into their financial reality.

“We have considered remortgaging everything we have, but have worked out if we did we would be homeless, on the streets with four kids, in just two years,” she said.

The Horder family have set up a crowdfunding page where individuals can donate to provide much needed financial assistance.

The site that has only been up since April of this year has already exceeded its $50,000 target but the need for aid is ongoing.

A petition calling for action has also been started by a friend of the Horder family. It will be delivered to Health Minister Sussan Ley. You can support Mia and Max by signing the petition here.