Drugs giant AstraZeneca was today celebrating its latest victory in the battle to protect its most valuable medicines from cheaper, unauthorised copies.

The Standard & Poor’s 500 index climbed to its highest level in 17 months today as strong earnings and merger news helped the stock market shake off a weak consumer spending report. The three main gauges posted a weekly and monthly gain.

Wall Street ended an indecisive week on a quiet note yesterday, with investors half-heartedly picking up shares in response to strong sales from McDonald’s.