Why are patients with kidney disease often not considered for clinical trials?

Why are patients with kidney disease often not considered for clinical trials? It's actually related to several things. One of them is that when trials are initially launched, the goal is to get the drug approved. And unfortunately, patients that have kidney disease are at risk for having other problems. And if a drug does not move forward because a few patients had some major side effects from it, then the whole community is not going to be able to benefit from it. So we ideally want patients with myeloma, with as few other medical problems as possible, to give the drug the highest possibility of getting to approval. The second reason is that early on in development, we don't know how the drug is going to work in patients with normal kidney function, let alone decreased renal function. So we always need to know how it works in perfect organ function, heart, liver, lungs, kidney, before we can start branching out to patients with any compromised organ function.