About ARIMIDEXBreast cancer clinical trial results
If you are a postmenopausal woman with hormone receptor-positive early breast cancer, you may be concerned about reducing your risk of cancer coming back (recurrence). As you consider your breast cancer treatment options, it is important to understand the results of a clinical trial called the ATAC trial. "ATAC" stands for "ARIMIDEX, Tamoxifen Alone or in Combination."
Background on the ATAC breast cancer clinical trial
The ATAC study was one of the largest clinical trials of breast cancer treatment of postmenopausal women with early breast cancer. This clinical trial compared treatment with ARIMIDEX to treatment with the antiestrogen medication tamoxifen, either alone or in combination.
In an early analysis of the ATAC trial at 33 months, results comparing tamoxifen alone to a combination of ARIMIDEX and tamoxifen showed no significant difference.
Data from the ATAC clinical trial were analyzed at a median of 68 months, when the majority of women had completed the 5 years of treatment, and at a median of 100 months, when women had been off of treatment for 3 years or more. The data from these analyses showed that women who took ARIMIDEX experienced a lower rate of recurrence of their breast cancer or death from any cause, compared with those who took tamoxifen.
Other important information about the ATAC clinical trial of breast cancer treatment includes
- Participants in the ATAC trial included 9,366 postmenopausal women from across the globe with early breast cancer who were considered candidates for adjuvant hormonal treatment following initial treatment
- Over 6,000 breast cancer patients in the ATAC trial received either ARIMIDEX alone or tamoxifen alone as adjuvant treatment
- The women who participated in the trial have been followed for a median 100 months (8+ years) — through 5 years of treatment with ARIMIDEX and for 3 years after completion of treatment
Two oncologists discuss 68-month and 100-month ATAC trial results
To learn more about the ATAC trial results, view the video below.
To view the video, you need Adobe® Flash® Player installed. If you do not have Adobe Flash Player on your computer, you can download it here.
Adobe Flash Player is a registered trademark of Adobe Systems Incorporated.
If you cannot view the video, you can read about the ATAC trial results below.
The 68-month ATAC breast cancer clinical trial results
Data from the ATAC trial were studied after women had been on treatment for a median of 68 months. The data showed that women who took ARIMIDEX experienced a lower rate of recurrence of their breast cancer or death from any cause, compared with those who took tamoxifen.
In the ATAC clinical trial at 68 months of follow-up, ARIMIDEX helped more patients reduce their risk of cancer coming back compared with tamoxifen
In the 68-month ATAC trial results, treatment with ARIMIDEX was shown to be significantly better than treatment with tamoxifen for lowering the risk of breast cancer recurrence in postmenopausal women with hormone receptor-positive early breast cancer. At the time of the analysis, 8% of patients were still receiving or still on treatment.
The 68-month ATAC trial results showed that patients taking ARIMIDEX had a 17% improvement in disease-free survival compared to patients taking tamoxifen in the hormone receptor-positive subpopulation.
- Disease-free survival refers to patients who were alive and had not experienced a recurrence of their breast cancer at the time of the 68-month ATAC trial results
- 424 of 2,618 patients taking ARIMIDEX had a recurrence or died compared to 497 of 2,598 patients taking tamoxifen
Patients taking ARIMIDEX had fewer breast cancer events than those taking tamoxifen
- 402 out of 3,092 patients taking ARIMIDEX had recurrence of breast cancer, compared with 498 out of 3,094 patients taking tamoxifen*
- 35 out of 3,092 patients taking ARIMIDEX had breast cancer develop in the breast on the side opposite their original cancer, compared with 59 out of 3,094 patients taking tamoxifen*
- 324 out of 3,092 patients taking ARIMIDEX had cancer spread to other parts of their body beyond their breast, compared to 375 out of 3,094 patients taking tamoxifen*
*Patients may fall into more than one category.
In the ATAC breast cancer clinical trial, patients taking ARIMIDEX were less likely than those taking tamoxifen to stop treatment because of side effects
Certain side effects were looked at in the ATAC trial based on known activity of drugs like tamoxifen and ARIMIDEX.
These side effects were LESS LIKELY with ARIMIDEX.
|
|
|
|
|
Hot flashes
|
36%
|
41%
|
|
Vaginal bleeding
|
5%
|
10%
|
|
Vaginal discharge
|
4%
|
13%
|
|
Blood clots
|
3%
|
5%
|
|
Stroke
|
2%
|
3%
|
|
Endometrial (uterine) cancer*
|
0.2%
|
0.6%
|
These side effects were LESS LIKELY with tamoxifen.
|
|
|
|
|
Joint symptoms
|
36%
|
29%
|
|
All fractures
Fractures of spine, hip, or wrist
|
10%
4%
|
7%
3%
|
- Chest pain was reported in more women taking ARIMIDEX than in women taking tamoxifen (71 [2.3%] vs 51 [1.6%])
- Heart attack rates were similar in women taking ARIMIDEX and women taking tamoxifen (37 [1.2%] vs 34 [1.1%])
- More patients taking ARIMIDEX were reported to have elevated serum cholesterol compared with patients taking tamoxifen (278 [9%] vs 108 [3.5%])
The 100-month ATAC breast cancer clinical trial results
A recent analysis of a median of 100 months of clinical data from the ATAC trial shows ARIMIDEX to be effective and superior to tamoxifen at reducing the risk of breast cancer recurrence in postmenopausal women with hormone receptor-positive early breast cancer.
The 100-month ATAC data show ARIMIDEX works to help reduce recurrence both throughout the 5-year hormonal treatment regimen and for more than 3 years afterward.
ARIMIDEX is an aromatase inhibitor with over 8 years of clinical data — 5 years on treatment and more than 3 years of follow-up — in the initial treatment of early breast cancer in postmenopausal women. For more information, talk to your doctor.
Important Information About ARIMIDEX
ARIMIDEX is approved for adjuvant treatment (treatment following surgery with or without radiation) of postmenopausal women with hormone receptor-positive early breast cancer.
ARIMIDEX is approved for the initial treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer and for the treatment of postmenopausal women with advanced breast cancer that has progressed following treatment with tamoxifen. Patients with hormone receptor-negative disease and patients who did not previously respond to tamoxifen therapy rarely responded to ARIMIDEX.
Important Safety Information About ARIMIDEX
- Prescription ARIMIDEX is only for postmenopausal women. ARIMIDEX should not be taken if you are pregnant because it may harm your unborn child
- Based on information from a study in patients with early breast cancer, women with a history of blockages in heart arteries (ischemic heart disease) who take ARIMIDEX may have a slight increase in this type of heart disease compared to similar patients who take tamoxifen
- ARIMIDEX can cause bone softening/weakening (osteoporosis) increasing the chance of fractures. In a clinical study in early breast cancer, there were more fractures (including fractures of the spine, hip, and wrist) with ARIMIDEX (10%) than with tamoxifen (7%)
- In a clinical study in early breast cancer, some patients taking ARIMIDEX had an increase in cholesterol. Skin reactions, allergic reactions, and changes in blood tests of liver function have also been reported
- In the early breast cancer clinical trial, the most common side effects seen with ARIMIDEX include hot flashes, joint symptoms (including arthritis and arthralgia), weakness, mood changes, pain, back pain, sore throat, nausea and vomiting, rash, depression, high blood pressure, osteoporosis, fractures, swelling of arms/legs, insomnia, and headache
- In advanced breast cancer trials, the most common side effects seen with ARIMIDEX versus tamoxifen include hot flashes, nausea, decreased energy and weakness, pain, back pain, headache, bone pain, increased cough, shortness of breath, sore throat, and swelling of arms and legs. Joint pain/stiffness has been reported in association with the use of ARIMIDEX
- ARIMIDEX should not be taken with tamoxifen or estrogen-containing therapies
Please click here for full Prescribing Information.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.FDA.gov/medwatch or call 1-800-FDA-1088 (1-800-332-1088).