The collapse Sangamo Therapeutics’ shares, by 48%, after results of its Champions trial were released has raised questions about the US gene therapy company’s management and the future of its gene-editing approach.

The biotech company shares fell on news of the results from its trial to develop a zinc finger nuclease gene therapy for mucopolysaccharidosis (MPS) types 1 and 2, a rare condition that results from the build-up of glycosaminoglycans (GAGs) due to the lack of an enzyme (IDS) within the body.

In a historic event, Sangamo earlier presented evidence that its zinc finger technology had successfully managed to edit the human genome to create new IDS in the liver, confirming that integration of their transgenic system led to the expression of mRNA, a precursor to the creation of the curative enzyme.

The trial results raised concerns that the therapy will be unable to integrate enough corrective genetic material into the genome to produce therapeutic levels of the enzyme, meaning the treatment will have little effect in its treatment of MPS.

In response, shares in the company fell to a decade low of $8.31 per share. The majority of Sangamo’s future value is tied to the success of its zinc finger platform, making the trials especially important to its long-term financial health.

CRISPR poses a long-term threat

A key issue is that Sangamo is not the only company developing gene editing therapies. The emergence of alternative technology, CRISPR, has created pressure to produce results.

CRISPR is newer and more convenient to use in a lab than zinc fingers but has not been as extensively tested. Treatments under investigation are currently in early-stage trials, with the leader in the field under development by rival gene therapy company Editas Therapeutics.

There is a risk CRISPR will quickly advance to become the dominant gene editing tool, and Sangamo appears to have failed to mitigate the market’s concerns about the underlying benefits of zinc fingers.

Sangamo’s management

Alongside this, questions have been raised about Sangamo management’s judgement, in part due to the favourable spin put on the precursory results last year.

A key R&D employee has also recently left.

A future for zinc finger technology?

However, with the value of Sangamo now around half that of the larger CRISPR gene editing companies, and as the only company to date that has achieved modification of the human genome inside the body, the company’s future is far from lost. It now looks to be at a significant discount when compared to others in the field.

In the race to develop and validate the perfect gene therapy platform, zinc fingers remain a favourite underdog.