My mom had small cell lung cancer metastacized to the liver. Her second line of treatment was very effective for ten cycles and it was a trial drug called amrubicin. Go to clinicaltrials.gov and look for research studies involving that drug. Very few side effects compared to her first round with cisplatin and etoposide. It is in in the third phase of the trials which is the last phase before it gets approved by the FDA....so it is helping a lot of people and has passed several tests already.
Hope you can find something that helps........I would advise doing your own reseach at clinicaltrials.gov because the clinicians you meet at any research facility will definitely be looking for people that "fit" the guidelines for their particular studies. So if you have more info about other trials out there, you can ask the right questions and consider trials that may be currently being offered by other clinicians in the same facility.