Pharma, Startups

Breast cancer drug with companion diagnostic head for clinical trials

Personalized medicine is continuing to evolve to the point where we have drug makers developing […]

Personalized medicine is continuing to evolve to the point where we have drug makers developing drugs that come with a companion diagnostic, developed with the help of a diagnostic partner. Arno Therapeutics is developing a personalized therapeutic with companion diagnostic to combat breast cancer linked to the hormone progesterone. The drug, onapristone, is expected to enter the clinic in the second half of the year.

The Flemington, New Jersey-based company’s therapeutic is designed to block signals from the hormone to progesterone receptors that promote cancer cell growth. The therapeutic was shown in pre-clinical studies to reduce the size of breast cancer tumors.

The companion diagnostic is designed to identify the activated form of the progesterone receptor to better identify which patients with progesterone receptor positive tumors are likely to respond to anti-progestin treatments, including onapristone.

Among the secondary cancer indications for the drug are endometrial cancer, ovarian cancer, uterine sarcomas and prostate cancer.

Anti-progestins are coming back after falling out of favor years ago due to high profile failures. RU-486, for example, known as mifespristone, was tested on women with breast cancer, but had a relatively low response rate and only short lived stabilization for the disease. More importantly, it significantly increased the levels of the estrogen hormone by four times — a situation that could cause breast cancer tumors to grow.

Despite a high response rate for women with breast cancer, Schering AG halted its onapristone development program for all indications secondary to liver toxicity issues, according to Arno Therapeutics CMO Dr. Alex Zukiwski in an emailed response to questions.

He emphasized that although mifepristone has activities that in certain situations can make it behave like a progestin agonist rather than an antagonist, onapristone has little if any other effects beyond blocking the activity of progestin receptors.

It makes a lot of sense to have a companion diagnostic for a drug. It could theoretically determine the best candidates for the drug, improving the quality and cost of clinical trials and outcomes to boot, making regulators happy as well as drug developers, right?

But Tuft University Center for Drug Development sounds a note of caution about this emerging trend. Will investors be willing to fund research for companion diagnostics? Will insurers provide reimbursement for them? And just like any innovative approach to drug development, there are questions about clinical and cost effectiveness because there’s relatively little data about the value companion diagnostics can give patients.

Shares0
Shares0