BIT Science Discussion, page-249

All drugs are toxic at a high enough dose, the question that you are concerned about is if the drug is toxic at the effective dose. For BIT225 this is currently unknown.

The other issue you need to worry about is idiosyncratic toxicity. Plenty of drugs are safe in 99.9% of patients, but kill 0.1%. It can be really hard to identify if your drug will have such a toxicity is a small number of patients and more than one drug has failed in phase 3 or post approval due to rare toxicity.

The bar you have to jump over with a new drug is dependent on the severity of the disease and the treatment options available. While HIV is a serious illness, there are now many treatment options to the point where almost all western patients can be kept healthy. Any new HIV drug needs to jump over a very high threshold these days.

Once again I am not saying that BIT225 is not going to succeed, just that it has a long, long way to go.