In London the FTSE 100 Index closed up by 0.8 points a short while ago to 4790.2.
GlaxoSmithKline shares have risen after the US Food and Drug Administration paved the way for two disputed drugs to return to market.
In afternoon trade, GSK shares were up 81p or 6.5% at 1322p.
Investors were also buoyed by a 17% increase in first-quarter profit.
Oil prices carried on falling today, after plunging nearly 5% the previous day, their biggest one-day fall this year.
Unexpectedly strong US stock piles triggered the price falls, easing fears of summertime shortages when Americans take to the roads in greater numbers.
Shell has reported a 28% increase in first-quarter profit thanks to surging oil prices.
The Anglo-Dutch energy giant reported current cost of supply (CCS) earnings of $5.54bn (£2.91bn), beating the forecasts of analysts.
Meanwhile, oil firm Exxon Mobil posted first quarter net profits of $7.86bn.
This does not seem to have helped the firm much as it is currently leading a retreat on Wall Street as oil prices have dipped below $50 a barrel.
JDS Uniphase Corp, the biggest maker of parts for fiber-optic networks, has also seen its shares tumble after saying sales this quarter will miss analysts' estimates.
The Dow Jones is currently down 61.56 points to 10,137.24 following the publication of a government report which says economic growth has slowed more than forecast in the first quarter as inflation accelerated.
For the month, the Dow average has slid 3.4% as a result of concerns the economy is slowing more than economists expect. The benchmark is headed for its worst month since January 2003.IFAonline
Taking the time to look
After 14-month FAS programme
More than half of people over the age of 55 see financial security as a top priority in retirement, yet a third allocate more time to buying a new car, research from Legal & General (L&G) has found.
Rebranded from OMW
Number of benefits