i think is to limit the time, i mean should concise and precise the time-event , consider factors that can effect The study ., also coding every day data is a good strategy makes aware the study . also you should on eye the censored time .
You should have data with at least three variables (time, event, drug). Plot and kaplan meier survival curve on the basis of drug. Use long rank test to assess effectiveness of drug. If you have other covariates, use cox PH model after testing for proportionality.