TDM-1 for HER2 positive esophageal and gastric cancer if herceptin stops working

I asked about this for someone on  the SMART PATIENTS site which also has a forum for EC. Robin M, the community coordinator at Smart Patients gave me the following answer( I would encourage people to join Smart Patients as well ) best, danièle:

"TDM-1, trastuzumab emtansine or Kadcyla, was approved by the FDA in February 2013 for treatment of metastatic breast cancer that is HER2 positive.

In the US, any drug that is FDA-approved can be prescribed by any physician for any purpose for which the physician thinks the drug will be effective. This is called off-label prescription.

Therefore, getting this drug prescribed for esophageal cancer is a judgment call on the part of the physician.

If insurance refuses to pay, the physician can appeal the refusal using whatever evidence is available. If the evidence is sound, the insurance company usually will approve the payment on appeal.

If there is little/no evidence and it's just a guess or a last-ditch effort by the physician, the patient can still get the drug by self-paying for it. The manufacturer might help with the cost."