The reverse takeover will allow Amryt to gain access to public markets without the expensive and often tortuous IPO process.
The process, which will require approval by Fastnet shareholders, involves Fastnet issuing enough new shares to Amryt to enable the latter company to take control.
Amryt is to embark on a fundraising process via issuing new shares, which will fund the new entity's product development programme. The cash will transfer to the company when the reverse takeover is complete.
Davy Stockbrokers will lead the fundraising and an investor roadshow is believed to be commencing as early as next week.
The new entity will be chaired by Harry Stratford, the founder of pharmaceuticals giant Shire.
Joseph Wiley, formerly medical director of Astellas Pharma, will be chief executive and Trinity Biotech's chief financial officer, Rory Nealon, will hold the same role at Amryt.
Amryt has signed conditional deals to buy two companies - Som Pharmaceuticals and Birken - which will complete if the reverse takeover goes ahead.
Amryt would then have a product, approved by the European regulator, which will be developed as a treatment for epidermolysis bullosa (EB), a genetic skin disease that causes painful blisters to form as a result of the slightest friction. Going public will enable the company to scale more quickly. The disease was the subject of a well-known Channel 4 documentary entitled The Boy Whose Skin Fell Off.
Other products for treating other rare diseases are in the pipeline.
It's believed that Dublin-based Raglan Capital had helped to put Amryt together. The deal is in line with Fastnet's new investing policy that was approved by shareholders at a general meeting in August.
Previously known as Fastnet Oil & Gas, it exited the oil and gas industry as a result of the turbulence in that sector.
The new investing policy was that Fastnet would acquire companies or businesses in the healthcare sector, particularly those in the biopharma sector.
If the policy had not been implemented within 18 months of the meeting, Fastnet's admission to trading in Dublin and on the Alternative Investment Market (AIM) in London would have been cancelled, and shareholders would have been asked if they wanted to wind up the company.