crispr stocksShares in various companies using gene editing technologies fell earlier this week, after it was widely reported that CRISPR-Cas9 may raise the risk of cancer in edited cell populations. CRISPR Therapeutics, Intellia Therapeutics, and Editas Medicine were among those affected.

Yesterday, FLG reported on a new study published in Nature Medicine that suggests CRISPR could increase the risk of cancer developing within the edited cell population. This is because cells without a functional p53 pathway, which stimulates cell death in the event of significant DNA mutation, are more likely to survive after gene editing has taken place. As a result, the cell population after CRISPR has been used is likely to have a higher concentration of cells without this DNA damage response. Cells without functional p53 have commonly been associated with a broad range of cancer types and thus the authors of the study reasoned that CRISPR may lead to an increased risk of the disease.

In response to this news, multiple companies known to be working with the CRISPR-Cas9 system saw their stock prices dip. CRISPR Therapeutics, a Swiss biotech looking to use gene editing to develop new disease medication, suffered from a 12.6% decrease and a massive increase in share volume (up to 8.3M from an average of 1.7M). Similarly, Intellia Therapeutics dropped 9.8% and had their share volume rise from 2.8M to more than 8M.

When contacted by MarketWatch, a representative from Intellia reported, “We’ve observed no signs of this type of toxicity or cells transforming into cancer or tumours in Intellia’s in vivo and ex vivo programmes. Despite extended observation in animals and in vitro cultures, we have not seen this effect. Intellia’s current approaches are directed at different cell types.”

Editas were also affected, with a stock drop of 7.8% and a share volume increase of more than four times their full day average, totalling 4.5M.

A statement from Editas that was supplied to MarketWatch reads, “For making medicines, we believe inhibiting p53 to increase homologous damage repair is not appropriate or needed as it could allow the accumulation of unwanted mutations from non-CRISPR mechanisms, and we can now achieve much higher targeted integration rates and gene correction without suppressing p53 than the authors of this paper saw in their experiment.”

Despite these drops, CRISPR-relate stocks have been increasing dramatically over the last few months. Only time will tell if the hiccoughs earlier this week will have a lasting effect on the market.