Orchard Therapeutics has listed in the US following a $200m initial public offering that came just three years after the gene therapy developer was spun out of UCL.

When Orchard Therapeutics, a UK-based gene therapy spinout of University College London (UCL), was selected for the GUV Deal of the Year 2018 it was in recognition of its $110m series B round raised in December 2017, backed by investors including university venture fund UCL Technology Fund and Singaporean state-owned investment firm Temasek.

A series B round of that size might be enough to last most companies a while, but not if they are as ambitious as Orchard. In fact, between being chosen as the winner for the award in early April and Chris Baker, senior business manager at tech transfer office UCL Business collecting the award at GUV: Fusion in May, Orchard signed a deal with pharmaceutical firm GlaxoSmithKline (GSK) to sell a 19.9% stake.

The deal with GSK gave the spinout access to several approved and investigational therapies for rare diseases and reinforced the notion that with Orchard Therapeutics, UCL had created something truly special.

The success story continued rapidly. In August, Orchard closed a $150m oversubscribed series C round that featured medical marketing group Medison’s corporate venturing subsidiary Medison Ventures and healthcare management services provider Sphera Global Health Care. Deerfield Management – the investment firm that keeps making headlines with $65m commercialisation funds established in partnership with US universities – led the series C round, which again included Temasek and a dozen other investors.

Then, early last month, Orchard filed to raise some $173m in an initial public offering – choosing Nasdaq over a stock exchange in its home country. That news must have been upsetting not only to the heads of the London Stock Exchange but to everyone in Westminster who is keen to turn the UK into a land of unicorns.

Losing such a darling of the investment world to the other side of the pond ought to send shockwaves through politicians’ offices – if the UK cannot convince a well-funded spinout to list domestically, it needs to have a frank discussion that is not reduced to the tired argument that tech transfer offices are to blame. After all, UCL Business and UCL Technology Fund put their full weight behind this one – they always do.

For Orchard, listing in the US has done nothing to impede its march to greatness. Instead of raising $173m, it secured $200m in an initial public offering that consisted of nearly 14.3 million American depositary shares priced, surprisingly, at the bottom of its range – $14 each.

Shares fluctuated marginally throughout the first days of trading, closing at $14 on Friday. The company’s market capitalisation currently stands at almost $1.2bn.

The 30-day overallotment option consists of more than 2.1 million shares which, if exercised in full by underwriters, would increase proceeds from the initial public offering to $230m. It may seem unlikely if the price sticks close to $14, but it is early days.

Founded in 2015, Orchard is developing ex vivo gene therapies based on a patient’s own haematopoietic stem cells in order to treat immune system deficiencies, neurometabolic disorders and hemoglobinopathies – genetic defects that affect the haemoglobin molecule.

The spinout was formed through a partnership between UCL Business and F-Prime Capital Partners, an investment subsidiary of financial services group Fidelity. It is based on work led by Bobby Gaspar and Adrian Thrasher at the UCL Institute of Child Health.

Gaspar, professor of paediatrics and immunology at UCL and an honorary consultant in paediatric immunology at Great Ormond Street Hospital, is chief scientific officer of Orchard, while Thrasher, professor of paediatric immunology, is on the scientific advisory board.

Orchard will use $84.5m of its IPO proceeds to design and construct a dedicated manufacturing plant, while $65.8m will go towards registrational trials and regulatory approval submissions for three drug candidates, establishing clinical proof of concept for a fourth and advancing three additional preclinical candidates.

A total of $17.8m is earmarked for the commercialisation of Strimvelis, a treatment for immunodeficiency disorder Ada-Scid that has been available in the EU since 2016. Ada-Scid is also known as bubble boy disease because affected children are vulnerable to infectious diseases and some have to live in sterile environments.

Orchard’s major shareholders include GSK, which retains a 14.8% stake, F-Prime, which now has 24.3%, Deerfield, which owns 5.5%, and Scottish Mortgage Investment Trust, which now holds 4.6%.

JPMorgan, Goldman Sachs and Cowen are joint book-running managers for the IPO while Wedbush PacGrow is co-manager.