Of particular interest following comment to "removed article".
"The linker and payload used in Kadcyla is - without modification - ImmunoGen's thioether linker (SMCC) and payload (DM1). This ImmunoGen technology has been used in Kadcyla the entire time Kadcyla has been in the clinic - the product was not "re-engineered to gain FDA approval". ImmunoGen holds the composition of matter patent on Kadcyla in the US.
ImmunoGen uses its SMCC/DM1 linker/payload pairing in wholly owned ImmunoGen product candidates (e.g., IMGN529); some other ImmunoGen partners have ADCs in the clinic with this pairing.
It is unfortunate for all involved, including Seeking Alpha, when incorrect information is published as fact."
http://seekingalpha.com/article/3024126-immunogen-investors-shouldnt-read-too-much-into-the-takeda-deal