Phase III study data failed to show benefits of adding drug to postsurgery chemo and hormone therapy.
Novartis is withdrawing its supplemental marketing authorization applications in the U.S. and Europe for the use of Zometa® (zoledronic acid) as adjuvant therapy of premenopausal women with hormone receptor-positive (HR+) breast cancer, on the back of Phase III study data that failed to show that the drug boosted disease-free survival. The firm said it is now evaluating future plans for the drug in this indication.
Novartis stresses that withdrawal of the regulatory submissions has no impact on the currently approved indications for Zometa. These include use of the drug to reduce or delay skeletal-related events in patients with a range of metastatic cancers involving bone and multiple myeloma, as well as for the treatment of hypercalcemia of malignancy.
The potential anticancer benefits of Zometa had been indicated previously in a Phase III trial (ABCSG-12) that included over 1,800 premenopausal women with HR+ early-stage breast cancer. This study suggested that adding Zometa to hormonal therapy after surgery over three years improved disease-free survival by 32%. Data from this trial formed the basis of the supplemental marketing submissions filed in 2009.
However, a second interim analysis of the more recent Phase III Azure study failed to uphold the ABCSG-12 trial findings. Azure involved 3,360 pre- and postmenopausal women with early breast cancer, and the interim data just reported showed that adding Zometa to standard post-surgery adjuvant chemotherapy and/or hormonal therapy had no benefits on disease-free survival. Novartis does, however, point out that a preplanned analysis based on menopausal status did indicate both a disease-free survival and overall survival benefit of Zometa adjuvant therapy in women with well-established menopause.
The firm claims Zometa is the most widely used bisphosphonate in oncology applications. The drug is approved in over 100 countries and has been used to treat over 3.9 million patients worldwide. Zometa made worldwide sales just shy of $1.5 billion in 2009, and $363 million in the third quarter of 2010.
Zoledronic acid is also the active ingredient in Novartis’ once-yearly Reclast/Aclasta osteoporosis therapy. Reclast/Aclasta made sales of $472 million in 2009, up 86% on 2009. It achieved sales of $143 million in the third quarter of 2010, up 15% on the same quarter the previous year.
In October Novartis reported new long-term data reinforcing the long-term efficacy and safety profile of once-yearly Aclasta in postmenopausal women with osteoporosis. The trial, including over 1,200 women, showed that women treated using Aclasa for six years had a 52% lower risk of new morphometric spine fractures compared even with those who received the drug for three years. Bone mineral density among patients who stopped Aclasta treatment after three years decreased, but still remained well above the levels measured at the beginning of the study