(ShareCast News) - Healthcare group Hutchison China MediTech posted a drop in first-half pre-tax profit as it invested more heavily in research and development.For the six months ended 30 June, pre-tax profit came in at $3.9m from $7.3m as a higher spend in R&D and cost of sales offset an increase in revenue to $65.7m from £30.3m.Hutchison said the revenue growth was driven mainly by a full period of consolidation of Hutchison Sinopharm, which began operations in the second quarter of last year.The company said spending on clinical activities was around $30.3m, up from $22.3m in the first half of last year, with 17 clinical trials now underway, compared with 10 last year, and a further seven due to start in the second half.Chief executive officer Christian Hogg said: "Chi-Med has made great progress on all fronts so far this year. Our vision is to become a major China-based pharmaceutical company - we believe we will achieve this by being an important innovator in the global targeted therapy arena. In line with this, during the first half, Chi-Med and its partners invested over $30 million pushing our oncology and immunology clinical pipeline as hard and fast as we could."At 1042 BST, shares were down 4.3% at 1,641p.