When will you risk drug induced death

Fox RJ, Salter A, Alster JM, Dawson NV, Kattan MW, Miller D, Ramesh S, Tyry T, Wells BW, Cutter G. Risk tolerance to MS therapies: Survey results from the NARCOMS registry. Mult Scler Relat Disord. 2015 May;4(3):241-9.
BACKGROUND:There is little information about risk acceptance of multiple sclerosis (MS) patients to various MS therapies.
OBJECTIVE:To determine MS patients׳ tolerance to risky therapies and identify associated characteristics.
METHODS: MS patients from the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry׳s online cohort were invited to complete questionnaires on decision making and risk tolerance (RT) to two therapeutic scenarios: a theoretical cure for MS [CureMS], with permanent reversal of all MS symptoms but a risk of immediate painless death; and natalizumab [NAT], a real-life scenario with benefits and risks as defined by Phase III trial results.
RESULTS: The median RT for both scenarios was 1:10,000; 15-23% of respondents were not willing to take any risk for their MS therapy. Participants with greater disability or not taking any MS therapy showed a greater RT, while females and those caring for dependants had a lower RT. Females and older age were predictors of lower RT, while increasing disability and greater blunting attitude with respect to information seeking behaviour were predictors of higher RT.
CONCLUSION: MS patients displayed a wide range of RT for MS therapies. Our study identified gender, age, disability and information seeking behaviour to be associated with RT.

So you can read the study which says  if the risk of death you would accepted this in 1 in 10,000 chance of risk of death for a hypothetical cure. Gilenya is associated with relatively immediate adverse effects as is alemtuzumab.  Is this latter a cure? We don't know and certainly not for some as people need retreating. However, are you queuing-up to be treated I don't think so. 

But what about Tysabri. So the risk of death from PML is about 1 in 5 of people affected by PML and the risk of PML is about 1 in 100 for some groups of MSers so about 1 in 500  which is somewhat lower than 1 in 10,000. 

I suspect you will say get the cure and then we can assess risk