Breast cancer is the second most common malignancy in women after skin cancer and accounts for one in three cancers diagnosed. Find out more about market developments in this chapter of Cancer Drug Discoveries. Breast cancer (BC) is the second most common malignancy in women after skin cancer and accounts for one in every three cancers diagnosed. Whilst the incidence of BC continues to rise in many countries there has been a fall in mortality rates from BC over the last decade. This reflects both more effective screening and treatment and an increase in public awareness.

Despite these improvements BC is still particularly prevalent, with an estimated 2.7 million people affected in 2005 in the top seven countries (US, Japan, France, Germany, Italy, Spain and the UK). Survival statistics have improved predominantly due to early detection of the disease which responds well to treatment.

The most interesting drugs in development for BC include the new SORMS (Evista, arzoxifene and Oporia) and the aromatase inhibitor combination atamestane (Intarcia Therapeutics), the epothilone analogues (ixabepilone, patupilone and ZK-EPO) which could compete with taxanes providing a balance can be established between efficacy and toxicity. New targeted therapies encompassing small-molecule drugs such as Tykerb (GlaxoSmithKline) and Iressa (AstraZeneca) and the monoclonal antibodies from Genentech/Roche, Avastin and Omnitarg, indicate the way this sector is going.

Key questions answered include:
What are the competitive pressures on Novartis' Femara and how might they affect revenues?
How will epothilone antagonists change the face of the BC treatment market and what effect will they have on Taxotere and Taxol?
What are the forecast sales of ixabepilone (BMS), Omnitarg (Genentech/Roche) and arzoxifene (Eli Lilly)?
What are the challenges facing Intarcia's atamestane?
What advantages and disadvantages can be seen in the many combination therapies being developed?

A number of leading BC agents face generic competition over the next five years.
CURRENT PRODUCTS EVALUATED AND FORECAST
ANTI-OESTROGEN
Nolvadex (AstraZeneca)
Faslodex (AstraZeneca)
Arimidex (AstraZeneca)
Femara (Novartis)
Aromasin (Pfizer)
Zoladex (AstraZeneca)

CHEMOTHERAPY
Taxotere (sanofi-aventis)
Taxol (BMS)
Abraxane (AstraZeneca/ Abraxis BioScience)
Ellence (Pfizer)
Xeloda (Roche)
Gemzar (Eli Lilly)

TARGETED THERAPIES
Avastin (Roche/Genentech/Chugai)
Herceptin (Roche/Genentech)
Tykerb (GSK)

UP AND COMING PRODUCTS EVALUATED
PHASE III
Arzoxifene (Eli Lilly)
Atamestane (Intarcia Therapeutics)
Evista (Eli Lilly/Chugai/ Daichii Sankyo)
Ixabepilone (BMS)
Oporia (Pfizer)
Patupilone (Novartis)
Tesmilifene (YM BioSciences)

PHASE II
Iressa (AstraZeneca)
Omnitarg (Genentech/Roche)
ZK-EPO (Bayer Schering Pharma).