Study of Valproic Acid (VPA) vs Placebo to Shorten Time of Indwelling Pleural Catheter

The goal of this clinical research study is to learn if receiving valproic acid (VPA) compared to a placebo can reduce the amount of time you will need to have an indwelling pleural catheter compared to the standard of care, which involves using an indwelling pleural catheter alone. VPA is designed to stop cancer cells from dividing and maturing. This may cause the cancer cells to become less malignant and cause less pleural fluid production. A placebo is not a drug. It looks like the study drug but is not designed to treat any disease or illness. It is designed to be compared with a study drug to learn if the study drug has any real effect.