Say you'll die

Ciana is doing great in life: she has a loving husband, two adorable children, a flying career. Her sister Kieran is the complete opposite. She used to be forever single and had odd jobs here and there. When Ciana becomes sick, Kieran stumbles upon a clinical trial where she can take Ciana's place to fight the decease cursing through her blood. Kieran's younger, has a better chance of getting better, and she has nothing to lose. They both jump on the opportunity but when the trial ends, and the results come back negative, the sisters need to make a hard choice. One of them will die.