The chairman of Verona Pharma increased his stake in the company following Monday's news that the biotechnology firm has dosed its first group of volunteers in its asthma trial.David Ebsworth showed confidence in the future of the business by purchasing 803,107 shares for 1.35p each, spending a total of £10,842 in the transaction. As a result, Ebsworth holds now 2.13m shares in the company.Broker N+1 Singer said this week's move was an "extremely positive step in Verona Pharma's development"."RPL554 has produced positive data to date, including synergistic effects with current standard therapy. There is also a potential Cystic Fibrosis indication for RPL554, offering a very attractive market opportunity for the group in a recognised Orphan disease. We believe RPL554 could generate very attractive returns to shareholders." Top Director BuysAFH Financial Group (AFHP) Director name: Mr Toby Denne Amount purchased: 16,000 @ 150.50p Value: £24,080Verona Pharma (VRP) Director name: Mr David EbsworthAmount purchased: 803,107 @ 1.35p Value: £10,842Top Director SellsAFH Financial Group (AFHP) Director name: Mr Toby Denne Amount sold: 16,000 @ 150.00p Value: £24,000