The UK pharma giant GlaxoSmithKline has increased its shareholding in Theravance, a South San Francisco-based biotech. With the investment close to $130 million, GSK is boosting its stake in the biotech partner Theravance to 19 percent.

The move showed the company’s confidence in the asthma/chronic obstructive pulmonary disease experimental drug Relovair, a promising late-stage respiratory drug developed in Theravance and positioned to become the likely successor of the blockbuster Advair.

Moncef Slaoui, chairman of R&D at GSK, said, ”We were keen to take advantage of this opportunity to increase our shareholding in Theravance”, He added that, “This reflects the confidence we have in the Relovair program and the wider late stage respiratory pipeline that we have built up through the collaboration.”

Relovair is a combination of the inhaled corticosteroid fluticasone furoate and the long-acting beta agonist vilanterol trifenatate. Investigators hope to get the experimental treatment, which is in late-stage trials in patients with COPD and asthma, to the marketplace by 2013.