InPharm | Ben Adams
A
new review of Roche’s breast cancer drug Herceptin has confirmed its ability to
increase overall survival, but concerns remain over its side effects.
The review was undertaken by Cochrane and involved a meta analysis of eight
studies involving 12,000 women with HER2-positive operable breast cancer, who
were randomly assigned to receive Herceptin or standard chemotherapy.
Clinicians then followed the women for an average of three years during and
after treatment, and the study found that Roche’s drug significantly reduced
recurrence and mortality in the women.
The drug was found to also significantly improve over survival in
HER2-positive women with early and locally advanced breast cancer.
But some patients in treatment developed severe heart toxicity (congestive
heart failure).
The review said that the drug reduced breast cancer mortality by one-third,
but the risk of heart toxicity is five times more likely for women receiving
Herceptin than women receiving standard therapy alone.
The review’s authors said that if 1,000 women were given standard therapy
alone (without Herceptin) then about 900 would survive and five would have
experienced heart toxicities.
If 1,000 women were treated with standard chemotherapy and Herceptin for
one year, about 933 would survive (33 more women will have their lives
prolonged.
About 740 would be free of disease recurrence (95 more women will not
experience the disease return), and 26 would have serious heart toxicity (21
more than the chemotherapy alone group) due to the drug. The authors noted however that heart toxicities are often reversible if the
treatment is stopped straight away.
The review said that longer treatment (over a year) with Roche’s drug
“might involve a greater risk of severe heart toxicities than shorter
treatment” (six months or less).
The authors concluded that the balance of risks to benefits in patients at
lower risk of recurrence (e.g., a small rather than a large tumour) must be
carefully evaluated before treatment is started.