The trust, managed by healthcare fund manager OrbiMed Capital, was launched in 2003. It has seen the best investment trust returns over the past five years (according to FE Trust Net) and a 50 per cent increase in its share price over the past 12 months.
It primarily invests in the worldwide biotechnology industry, principally in emerging biotech companies.
Newgate will handle the firm's financial and corporate comms and the win marks the first since Newgate owner Porta bought financial services specialist consultancy Cauldron in early March.
The agency is charged with helping to raise the profile of the trust among retail and institutional investors.
Anne McMeehan, director of Newgate Communications, said: 'The global biotech sector has matured over the past ten years and over this period the firm has been at the forefront of identifying and investing in emerging biotech firms.
'We believe there will be a continued resurgence in investment trusts and that with the pressures posed by an aging population, coupled with an increasing focus on new healthcare products, the trust is well placed to maximise returns.'