Biotech Values

[rfj1862]

RPRX

>I'm not sure the impetus for developing this product..seems like another version of mifepristone to me?!<

I can answer that.

RU-486 is NOT equivalent to Proellex. Beyond the obvious structural differences, RU-486 does not appear to be antiproliferative in the primate endometrial epithelium or stroma. In fact, RU-486 may elicit proliferation to a small extent. Both Lupron and Proellex are provide a fairly profound suppression of proliferation.

Source: http://www.zonagen.com/html/ppt/ZONA_BIF.ppt [slide 8]

Also, according to the most recent reliable data I can find, mifepristone just doesn't work. This is consistent with the previous source suggesting that mifepristone does not influence proliferation.

"It is known that there are progesterone receptors on endometrial implants in women with endometriosis. Small, uncontrolled trials have shown that mifepristone can decrease pain in women with diagnosed endometriosis. Yet, there was no objective decrease in the extent of ectopic endometrial implants on follow-up laparoscopy."

Source: http://archfami.ama-assn.org/cgi/content/full/7/3/219

Also, I see a only a few small uncontrolled trials of RU-486 in endometriosis and a bunch of reviews claiming it has promise. Seems a very bold statement to me to say that "RU-486 is an equivalent generic."

Also, from a strictly practical point of view:
1) Why would TAP and Schering have spent hundreds of millions on asoprisnil if there wasn't a market in endometriosis and uterine fibroids?
2) As you've alrady noted, RU-486 carries a considerable stigma. That alone will push women into other drugs.