Merck 2008 Annual Report Download - page 47

42 | Merck Annual Report 2008
New therapeutic options for cancer treatment with Erbitux®
The results of numerous studies involving the monoclonal antibody Erbitux® (cetux-
imab) impressively demonstrate the consistent efficacy and versatility of this targeted
cancer therapy. In metastatic colorectal cancer, for example, it is now possible to use
the KRAS gene as a biomarker to identify those patients who are most likely to respond
to treatment with Erbitux®, namely those with KRAS wild-type tumors.
The results of the Phase III CRYSTAL trial underline the value of Erbitux® as a new
standard in first-line treatment of metastatic colorectal cancer. In this large random-
ized trial, 60% of all patients with KRAS wild-type tumors experienced significant
tumor shrinkage when treated with Erbitux® in combination with chemotherapy –
clearly exceeding the results achieved with chemotherapy alone. The ability of Erbitux®
to shrink the tumor translated into a substantially decreased risk of tumor progression
and a trend towards prolonged survival for all patients with KRAS wild-type tumors.
Furthermore, effective tumor shrinkage might allow complete surgical resection of
liver metastases, thereby enhancing the chance of a potential cure. A further random-
ized Phase II study (CELIM) investigated the efficacy of Erbitux® in combination with
standard chemotherapy in patients with initially inoperable liver metastases. Tumor
shrinkage was experienced by 79% of patients with KRAS wild-type tumors, and 43%
of these patients underwent surgery. A complete surgical removal of the tumor was
achieved in 34% – a chance for these patients to be cured. These data are among the
best ever achieved for complete surgical removal of liver metastases in metastatic
colorectal cancer.
Erbitux® in lung and gastric cancer
A Phase III clinical trial (FLEX) proved that in first-line treatment in combination
with a platinum-based chemotherapy, Erbitux® can significantly prolong median over-
all survival of patients with non-small-cell lung cancer (NSCLC) across all histological
patient subgroups. This effect was more pronounced in FLEX patients treated with
Erbitux® who developed early acne-like rash, resulting in median overall survival of
15 months. Lung cancer is one of the leading causes of cancer death worldwide: Among
men, it claims more lives – around 975,000 per year – than any other form of cancer.
Among women, it is responsible for 376,000 deaths each year, second to breast cancer.
A further Phase III clinical trial (EXPAND) was started in the third quarter of 2008
to investigate the efficacy of Erbitux® in combination with chemotherapy as a new
option in first-line treatment of gastric cancer. Every year, nearly 930,000 people are
diagnosed with gastric cancer and around 700,000 die from it.
Expanding treatment possibilities in oncology
Two further compounds, Stimuvax® and cilengitide, are currently in Phase III develop-
ment. Stimuvax® (BLP25 liposome vaccine) is an investigational therapeutic cancer
vaccine designed to induce an immune response to cancer cells that express MUC1, a
protein antigen over-expressed in many common cancers including lung, breast and
colorectal cancer. Stimuvax® is currently in a Phase III study involving patients with
non-small cell lung cancer (NSCLC). It is the first cancer vaccine in unresectable locally
advanced NSCLC to enter Phase III clinical trial testing (START). The results of a ran-
domized Phase II study found that after three years, almost twice as many patients with
unresectable advanced NSCLC receiving Stimuvax® were still alive compared to patients
in the control group.
Personalized medicine:
A genetic test identifies
patients who will respond
best to treatment.
Cancer vaccine Stimuvax®
designed to induce an immune
response to cancer cells.