HIV Rx May Become New HER2+ Treatment

HER2 positive breast cancer tumors in mice inhibited with Nelfinavir

(RxWiki News) Right now, fast-moving HER2-positive breast cancer is a tough one to battle. That fact may be changing, thanks to the findings that an existing medication may be the answer.

In a recent animal study, nelfinavir, the drug currently used to treat HIV+ patients, was effective in slowing the growth of HER2+ breast cancer tumor cells, even if those cells had become resistant to other drugs.

Nelfinavir, which is sold under the brand name Viracept, may be useful in treating human HER2+ breast cancer,

"Find out about all the drugs used to treat your condition."

HER2+ breast cancer has more of a protein called Human Epidermal growth factor Receptor 2, which encourages the growth of cancer cells.

This aggressive cancer appears in about 25 percent of the nearly 230,000 women who are diagnosed with breast cancer every year in this country. HER2+ breast cancer doesn’t respond well to treatment over time.

Nelfinavir is already known to be able to blunt the growth of some cancers. It’s currently being tested in clinical trials as a chemotherapy agent and as a drug that improves the effectiveness of radiation.

What if any affect it might have on HER2+ breast cancer was unknown.

To study this very question, Jun O. Liu, PhD, of the Department of Pharmacology and Molecular Sciences at Johns Hopkins School of Medicine, and colleagues screened drugs in the Johns Hopkins Drug Library for breast cancer cell inhibitors (blockers).

“New drug development, beginning from scratch, is extremely expensive and time-consuming, taking an estimated $1 billion and more than 10 years to get each new compound to market,” Dr. Liu said in a press release. “An existing drug has already passed most of the costly safety and regulatory hurdles."

For this study, Liu and his team started with breast cancer cells from two patients, then tested all of the drugs in the library for their ability to stop cells from growing and multiplying.

The field was narrowed to five drugs. Nelfinavir was identified and determined to have anti-tumor properties in mouse models of human breast cancer.

The drug blocked the growth HER2+ breast cancer in the animals.

The researchers also tested to see if nelfinavir could slow down the growth of tumors that no longer responded to the commonly used breast cancer drugs, lapatinib (Tykerb) and trastuzumab (Herceptin). They tested all three drugs, and only nelfinavir was able to keep drug-resistant cells from growing.

Nelfinavir, which is taken orally in pill or powder form, can be taken the same way and in the same dosage as it’s used to treat HIV.

"With a relatively low toxicity profile and much available information on its drug-drug interactions and on pharmacokinetics, Nelfinavir is ready for clinical testing in HER2 breast cancer patients," the authors write.

A 30-day supply of 250mg nelfinavir costs about $265.

The authors concluded that this discovery has "important implications in the development of Nelfinavir and its analogs as new anticancer agents."

The study was published October 5 in the Journal of the National Cancer Institute.

This research was supported by the National Cancer Institute, the National Center for Research Resources, Flight Attendant Medical Research Institute, the Commonwealth Foundation and the National Institute of Allergy and Infectious Diseases.

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Review Date: 
October 12, 2012