The trials themselves are generally small and prone to bias. Having said that, there are some positive findings that look interesting. Pycnogenol is felt to be possibly effective for asthma (it may reduce rescue inhaler use) when added to regular asthma medications. It may also improve leg pain and reduce feelings of heaviness in patients with chronic venous insufficiency. When taken for oseteoarthritis, Pycnogenol use reduced the need for anti-inflammatory medications, compared to a placebo.
As usual with this supplement stuff- it might help make things a little better but it probably isn't worth your time and money. And if it is, a doctor will probably be the one to tell you it is.