Drugs like Lipitor for treating high cholesterol ($1,500 a year), Zyprexa for schizophrenia ($7,000 a year) or Avastin for cancer ($50,000 a year) are often talked about as the most expensive drugs. However, none of them made it to Forbes’ exclusive survey of the planet’s most expensive medicines.

The nine drugs that made it to the list cost over $200,000 a year, with most treating rare genetic diseases afflicting fewer than 10,000 patients and for which there are few treatments, if any, which is why bio-tech firms charge pretty much what they want.

Soliris, a drug manufactured by Alexion Pharmaceutical retails at $409,500 a year and is the world’s most expensive drug for treating an immune system disorder that destroys red blood cells at night. Called paroxysymal nocturnal hemoglobinuria (PNH), the disorder affects 8,000 Americans, with Soliris’ sales for last year touching $295 million, causing its stock price to go up 130%.

The fewer patients a drug is able to help, the more its cost goes up, and Soliris before being tested for PHN was tested for rheumatoid arthritis afflicting 1 million Americans, but it failed the trials. If, it had worked for arthritis, Alexion would have charged a much a lower price for this it, as it would face competition against drugs costing a mere $20,000.

There are three other drugs that cost over $350,000 per year, such as, Shire Pharmaceuticals’ Elaprase ($375,000 per year) for treating Hunter’s Syndrome, an ultra-rare metabolic disorder that affects just 500 Americans, and which causes infections, breathing problems and brain damage. Last year, Elaprase’s domestic sales touched $353 million.

BioMarin Pharmaceuticals’ Naglazyme costing $365,000 a year, treats another rare metabolic disorder. Viropharma’s Cinryze, a treatment for preventing a dangerous swelling of the face costs an estimated $350,000 a year, with sales expected to increase from last year’s $95 million to $350 million a few years from now.

All the world’ most expensive drugs unlike standard dose pills are injected biotech drugs, with varying dosage by weight or other factors.

Forbes’ the world’s most expensive drug list was assembled with the help of interviews with bio-technology industry experts and the average price per patient obtained from the companies or Wall Street analysts covering them.

Surprisingly, many of the brutally expensive cancer drugs did not make it to the list, as targeted cancer drugs are use by only a small minority of patients for a few months, thus reducing their average cost. Allos Therapeutics’ Folotyn for treating a rare type of lymphoma costs $30,000 per month, however, the average patient is on the drug for just a few months, which doesn’t allow it to make it to the list.

While, biotech companies defend the high cost of their drugs saying, only a few patients will ever need them. Nonetheless, each new rare-disease specialty drug’s price gets higher every year, with drug pricing of $100,000 a year hardly raising any eyebrows.