Three directors in AIM-quoted biotech sector consolidator Proximagen have added to their holdings following the company's deal with BrainCells Inc for its sabcomeline programme.The Proximagen share price was flat yesterday but the news of the share buying sparked it into life and it ended up 16.5p at 100p. Chief executive Ken Mulvany, finance director James Hunter and non-exec Michael Ashton each bought 15,000 shares at an average price of 84p a share. The shares were bought on 4 and 5 August. Mulvany owns 1.39% of Proximagen, while Hunter owns 20,000 shares and Ashton 41,384 shares. BCI will pay Proximagen an up-front fee and milestone payments worth up to $51m for sabcomeline, as well as royalties on sales. However, most of this cash will not be paid for years and that assumes the clinical trials go as planned. BCI will own the worldwide rights to sabcomeline, which was acquired by Proximagen in February when it paid 6p a share for AIM-quoted Minster Pharmaceuticals, which valued the drug developer at £4.3m. Minster came with £3.5m in cash. Sabcomeline is a treatment for cognitive decline in schizophrenia, which was licensed from GlaxoSmithKline. This is not a core area for Proximagen, which focuses on treatments for neurological conditions. BCI will be responsible for milestone and royalty payments to GSK, as well as the clinical development, regulatory filing and commercialisation of the drug. A phase II trial is planned. In June 2009, Proximagen raised £49m at 140p a share. Proximagen still had £51m in cash and bank deposits at the end of May 2010. There was an outflow from operations of £3.5m in the year to May 2010. Proximagen is valued at £57.4m so there is little upside from its drugs recognised in the share price. Prior to today's share price rise the company was trading at below cash. Minnesota-based Upsher-Smith agreed a similar deal to the BCI one for PRX1, which is a programme for the symptomatic treatment of Parkinson's disease based on an improved version of L-Dopa - a known treatment. The upfront and milestone payments alone could come to $232m (£117m). Again most of these payments are a long way off, although Upsher-Smith did invest $6m at 227p a share in October 2008. Top Director BuyseXpansys (XPS) Director name: Mr Graham DawberAmount purchased: 339,000 @ 7.25p Value: £24,578Proximagen Group (PRX) Director name: Mr James Douglas HunterAmount purchased: 15,000 @ 84.00p Value: £12,600Proximagen Group (PRX) Director name: Mr Kenneth MulvanyAmount purchased: 15,000 @ 84.00p Value: £12,600Proximagen Group (PRX) Director name: Mr Michael AshtonAmount purchased: 15,000 @ 84.00p Value: £12,600MS International (MSI) Director name: Mr David PyleAmount purchased: 10,000 @ 121.50p Value: £12,150Top Director SellsHeavitree.A (HVTA) Director name: Mr Rodney J GlanvilleAmount sold: 7,000 @ 170.00p Value: £11,900