Even then, patients won’t get the treatments if insurers and governments balk at paying. It’s a real risk. For instance, a different gene therapy for beta-thalassemia, developed by Bluebird Bio, was pulled out of the European market after governments there refused to pay the $1.8 million price.
The first generation of CRISPR treatments are also limited in another way. Most use the tool to damage DNA, essentially shutting off genes—a process famously described as “genome vandalism” by Harvard biologist George Church.
Treatments that attempt to break genes include one designed to try to zap HIV. Another is the one Gray got. By breaking a specific bit of DNA, her treatment unlocks a second version of the hemoglobin gene that people normally use only as babies. Since hemoglobin is the errant protein in sickle-cell, booting up another copy solves the problem.
According to Liu’s analysis, two-thirds of current studies aim at “disrupting” genes in this way.
Liu’s lab is working on next-generation gene-editing approaches. These tools also employ the CRISPR protein, but it’s engineered not to cut the DNA helix, but instead to deftly swap individual genetic letters or make larger edits. These are known as “base editors.”
According to Lluís Montoliu, a gene scientist at Spain’s National Center for Biotechnology, these new versions of CRISPR have “lower risk and better performance,” although delivering them “to the right target cell in the body” remains difficult.
At his lab, Montoliu is using base editors to cure mice of albinism, in some cases from birth. It’s a step, he says, toward a treatment newborn humans could receive, although not to change their skin color. Instead, he dreams of putting Liu’s molecules in their eyes to correct severe vision problems that albinism can cause.
So far, though, the albinism project is not a commercial venture. And that points to one of the biggest limits on CRISPR’s impact now and in the foreseeable future. Nearly all CRISPR trials underway aim at either cancer or sickle-cell disease, with multiple companies chasing the exact same problems.