Ibrance Offers No More Benefits Than Other Breast Cancer Treatments, Analysis Says

Ibrance Offers No More Benefits Than Other Breast Cancer Treatments, Analysis Says

The breast cancer therapy Ibrance (palbociclib) offers no more benefits than treatments with which it was compared in clinical trials, according to an analysis by the German Institute for Quality and Efficiency in Health Care.

In addition, the institute’s dossier assessment, which covers a new therapy’s benefits once it reaches the market, concluded that data was inadequate or even missing for several treatment groups, including those receiving Ibrance as a second-line therapy. That makes an accurate assessment impossible, the institute said.

Ibrance is approved in the United States and Europe for women with HR-positive, HER2-negative locally advanced or metastatic breast cancer. The approvals are for a combination of Ibrance and either an aromatase inhibitor or Faslodex (fulvestrant) in women who received endocrine — or hormone — therapy earlier.

In examining possible benefits of the treatment, institute researchers looked at different patient groups, including both premenopausal and postmenopausal women, and women with previous treatments that were unsuccessful.

Pfizer, which manufactures Ibrance, had conducted two randomized clinical trials in postmenopausal women, who took it as a first-line treatment. The trials compared a combination of Ibrance and Femara (letrozole) with the use of Femara alone.

Researchers found no differences in benefits between the two groups when they compared the women’s health status, health-related quality of life, and discontinuation of treatment due to side effects. Women treated with the Ibrance combination had a longer progression-free survival, but overall survival was similar in the two groups.

Overall survival can be difficult to assess accurately in the short term, however, so cancer trials often use progression-free survival as a substitute measure.

But the institute noted that using progression-free survival as a substitute measure needs to be validated in order to prove that the drug provides additional benefits. “It is a good sign when the tumor does not continue to grow or even shrinks under a new treatment. It is not certain, however, that patients actually survive longer,” the researchers said in a press release.

Although Pfizer did a validation analysis, the institute pointed out that its researchers used studies that compared single treatments, while Ibrance is approved only as a combination therapy. Moreover, the validation analysis did not include studies of Ibrance, the institute said.

The institute decided to perform a new analysis that included data from the Ibrance trials. It concluded that progression-free survival was not a valid substitute for overall survival.

In addition, combination treatment with Ibrance produced more severe side effects than therapy with Femara only, according to the institute report. Since the increase in side effects was not accompanied by any advantages, the institute argued that Ibrance actually provides less benefit overall.

It also said Pfizer’s dossier did not include data on first-line treatment of premenopausal women or women in menopause. Finally, the institute said it was unable to assess Ibrance’s benefit as a second- or later-line treatment in women before, during, or after menopause because Pfizer’s researchers had failed to compare it with other therapies.

3 comments

  1. Linda Rodrigues says:

    Cancer 1996 MBC 2014 (in Bones) Only Ibrance/Letrozole has shrunk tumors and prevented progression to organs. Have been on Ibrance for 26 months. Side effects low WBC, hair thinning, exhaustion, rash. This is the only drug that I have been given with reasonable side effects and that works and contains the cancer for me. This is a chronic illness that I will always have. My goal is to contain it as long as I can with a decent quality of life. I will never have the life I had before cancer, but I am doing okay.

    • Sandra says:

      I will be starting this combination in the next 2 weeks. I also have mets to my bones (spine). Breast cancer in 2008, MBC June 27, 2017. I have all my faith in this new drug. I will just have to adjust to the side effects. I am just thankful to be alive.

  2. Rom says:

    My mother tried Ibrance but it unfortunately did not help her. Her original diagnosis was in 10/2000 (age 66) with treatment using chemo Taxol (paclitaxel) and partial mastectomy. Recurrence came in 12/2010 with inoperable stomach mets. After this she had chemo with Xeloda (capecitabine), regular hormonal therapy Femara (letrozole), Aromasin (exemestane). During this time, she lost her husband of 50 yrs, and eventually the conventional hormonal therapies’ side effects and ever-present cancer really attacked her, and I and Mom turned with hope towards Ibrance. Her oncologist thought to give it a chance, even though we knew that it was only ‘proven’ by Pfizer in those patients who had not undergone primary hormonal therapy and also for younger patients, my Mom was already 80. I was with her through most of her last year, it was very sad, because I could see that Ibrance was not helping her. Many tough days and nights that summer, then she stopped eating and passed away within 2 months of beginning and the quitting Ibrance. The mentally-related side effects of that time were very bewildering for her and for me. We were on an extremely difficult emotional roller coaster and my poor Mom was on the receiving end of almost all the fears and pains. The hormonal therapies I believe can create some real problems (anxiety, emotions, enhanced fears, etc.)for the suffering patients. I understand, the cancer relies on the hormones, but so do humans.. it is a tough battle. I pray for the improved therapies and oucomes. In the end, I was so happy for the extra years I had with Mom, but I was sad that Ibrance did not help, and also, I feel guilty because I was telling her how much hope there still was. Yes, she lived a long life, I am grateful, but I still miss her very very much , since it has been 2 years now! I think that Ibrance surely is helping many patients and I really hope it and other new treatments destroy cancer and give happy life back to all people.

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