Harvard scientist David Liu has been awarded the prestigious Breakthrough Prize, often called the "Oscars of Science," for his groundbreaking work on base and prime gene editing technologies that are revolutionizing treatment approaches for genetic diseases.
Liu, the Dudley Cabot Professor of the Natural Sciences and vice chair of the faculty at the Broad Institute of MIT and Harvard, developed these technologies as alternatives to the CRISPR-Cas9 system, which cuts through DNA like scissors.
"If your goal is to correct a mutation that causes a genetic disease, it's not easy to use scissors to achieve gene correction," Liu explained. This limitation led his team to develop more precise approaches to genetic modification.
Revolutionary Gene Editing Technologies
Base editing, developed by Liu's lab in 2016, allows scientists to correct single-letter "misspellings" in DNA by changing specific nucleotide bases (A, C, G, and T) without cutting the DNA's double-helix structure. This approach can address four of the most common types of mutations that cause genetic diseases.
For more complex genetic issues, Liu's team developed prime editing in 2019, which functions more like a word processor. This technology can search for flawed DNA segments and replace them with synthesized DNA flaps specified by the researcher, enabling correction of a wider range of genetic abnormalities.
"We can make just about any kind of change in the DNA of living systems, including correcting the vast majority of mutations that lead to genetic disease," Liu said.
Clinical Impact and Patient Success Stories
The real-world impact of these technologies is already evident. Currently, at least 18 clinical trials using base or prime editing are underway across five countries, treating a range of genetic conditions.
One of the most compelling success stories involves Alyssa Tapley, who at age 13 was suffering from T-cell leukemia with a grim prognosis after conventional treatments failed. A clinical trial using base editing cleared her cancer—the first human application of this technology.
"Now, 2½ years later, I'm 16, preparing for exams, spending time with my family, arguing with my brother, and doing all the things I thought I'd never be able to do," Tapley shared at the Breakthrough Prize ceremony.
Beyond leukemia, Liu's technologies have shown promising results in patients with sickle-cell disease, beta-thalassemia, and high cholesterol. The approach is particularly valuable for rare diseases that often receive limited attention from large pharmaceutical companies.
"It makes it economically feasible to create therapeutics for small markets," according to the Breakthrough Prize announcement, addressing a critical gap in the treatment landscape for rare genetic conditions.
From Basic Science to Medical Breakthroughs
Liu connects his innovations to decades of basic scientific research that began without clear applications. He points to the discovery of CRISPR sequences in bacteria at Japan's Osaka University in 1987 as an example of curiosity-driven research that eventually led to transformative medical technologies.
"This is the essence of basic science," Liu emphasized. "It all came from the basic science of geneticists who first looked at these clustered regularly interspaced short palindromic repeats and wondered what they were doing."
Liu's lab has distributed these technologies to more than 20,000 non-profit laboratories worldwide, fostering a collaborative approach to addressing genetic diseases. While cautious about using the term "cure," Liu acknowledges the transformative potential of these treatments.
"Scientists are reluctant to use that word until there's evidence of years without any apparent symptoms of the disease," he said. "But the writing's already on the wall: In some of these clinical trials, the patients are no longer on any medication and don't have any symptoms of the disease."
Future Challenges and Responsibilities
Despite the remarkable progress, Liu expresses concern about the current research climate, particularly for young scientists.
"There's a lot of fear and chaos now that is preventing young scientists from entering the phase of their careers where they can contribute to society in a direct way," he said. "And that's a very real tragedy."
Liu also acknowledges the responsibility that comes with developing such powerful technologies: "It's incredibly exciting, and also comes with a heavy sense of responsibility, to make sure that—to the extent humanly possible—we have done everything we can to make these agents as safe and effective as possible for use in patients."
With hundreds of millions of people worldwide suffering from genetic diseases, Liu's innovations represent a significant step toward addressing previously untreatable conditions. As clinical trials continue and more patients receive these gene-editing therapies, the full potential of base and prime editing in transforming genetic medicine is only beginning to be realized.
