Ibrance -- All Stages

ShetlandPony

In 2015 Ibrance (palbociclib) was approved in the USA as a targeted therapy, used in conjunction with an anti-estrogen therapy, for hormone-receptor positive metastatic breast cancer. There are now clinical trials testing Ibrance for early-stage breast cancer. This thread is meant to be a place to discuss and share about Ibrance for patients of any stage, since the original Ibrance 2015 thread is on the Stage IV Only forum.

jojo9999

Thanks for starting the thread. I look forward to learning more about the drug. What eactly does the drug do? Does it have something to do with mutations to the estrogen receptors?

ShetlandPony

Hi, Jojo. To answer your question, here is a quote from Pfizer's Ibrance web site:

In ER+/HER2- metastatic breast cancer, the presence of estrogen can cause an overactive signaling of proteins within the nucleus (center) of the cell that tells the cell to grow and divide.

Two of these proteins are called CDK 4 and CDK 6. The increased activity of these proteins inside the nucleus causes a loss of cell cycle control, which causes cells to grow and divide too fast.

IBRANCE (palbociclib) is in a new class of drugs called CDK 4/6 inhibitors that work to stop the proteins CDK 4 and CDK 6 from signaling. By stopping these proteins, IBRANCE puts the brakes on cell growth and division in healthy and cancer cells. This helps slow the progression of cancer, but it can also cause side effects, some of which are serious. Please see the Important Safety Information to learn more.

IBRANCE and letrozole impact cancer cell cycle progression in 2 different ways. IBRANCE works inside the nucleus (center) of the cell to inhibit CDK 4 and CDK 6. Letrozole works outside of the nucleus to decrease the production of estrogen. Together, these therapies help delay disease progression.

Kattysmith

"IBRANCE works inside the nucleus (center) of the cell to inhibit CDK 4 and CDK 6. Letrozole works outside of the nucleus to decrease the production of estrogen. Together, these therapies help delay disease progression."

Fascinating, thank you! I hadn't seen it put so succinctly before.

Dianarose

Hi, doc talked about putting me on this in a few months so I will be joining you in your new thread. In my chemo sensitivity test it came back as likely to work

ShetlandPony

That's great that your onc could use a chemosensitivity test for you. Do you know the name of the test? Ibrance is generally thought to be one of the easier treatments. Will you be in a trial, then?

Dianarose

I am going to get a copy of the tests on Monday and will share the information. That's why it was so important to do the biopsy as they needed some good amount of tissue with the cancer to do them. She did say that six chemos came back as likely to work. I don't think she will put me in a trial but right on the drug