The 17-year-old, who suffers from an aggressive cancer, lost his case against Sydney Children's Hospital in March in which he had argued that treating him with blood products or a transfusion would breach his relationship with God.
His appeal in the New South Wales Supreme Court against that judgement failed Friday after no basis was found to legally set aside the earlier order.
Justice John Basten said there was no reason why a different result should be achieved just because the applicant was now closer to his 18th birthday, which is in January, and at which point he can exercise his right to refuse treatment.
"The interest of the state is in keeping him alive until that time, after which he will be free to make his own decisions as to medical treatment," he wrote.
The teenager, who suffers from Hodgkin's disease, initially had several bouts of chemotherapy which achieved only a limited reduction in the size of many tumours, and no enduring remission of the disease.
His doctors recommended higher doses of different chemotherapy agents, ones which carried the inevitable side effect of anaemia and by February this year severe anaemia had set in, requiring either a blood transfusion or a cessation of treatment.
Advice was that he had an 80 percent chance of dying from anaemia without receiving a blood transfusion -- a treatment which goes against the beliefs of Jehovah's Witnesses.
The appeal judgement noted that while the boy's parents had also refused to consent to any treatment involving a blood or platelet transfusion, he was a "mature minor" with an understanding of his own condition.
However, it ultimately supported the decision of the first judge to allow treatment.
"There is no doubting (the applicant's) devotion to his faith, but his life has been cocooned in that faith," Justice Ian Gzell said at the time.
"The sanctity of life in the end is a more powerful reason for me to make the orders than is respect for the dignity of the individual."
The appeal judgement noted that the case had raised important issues and did not force the applicant to pay the costs of the case.