Gene editing technologies are moving forward in preclinical development with innovative strategies designed to treat diseases at their root and even reverse them.

Gene editing technologies are moving forward in preclinical development with innovative strategies designed to treat diseases at their root and even reverse them. However, many approaches still struggle to reach target cells or tissues – either they fail to arrive, or their efficacy is low. In vivo therapies face numerous challenges, but despite these hurdles, 2025 has marked a year of remarkable progress.

Gene editing technologies are moving forward in preclinical development with innovative strategies designed to treat diseases at their root and even reverse them. However, many approaches still struggle to reach target cells or tissues – either they fail to arrive, or their efficacy is low. In vivo therapies face numerous challenges, but despite these hurdles, 2025 has marked a year of remarkable progress.

Researchers at the University of Sydney have uncovered a mechanism that may explain why glioblastoma returns after treatment, and the world-first discovery offers new clues for future therapies. Glioblastoma is one of the deadliest brain cancers, accounting for about half of all brain tumors, with a median survival rate of just 15 months. Despite surgery and chemotherapy, more than 1,250 clinical trials over the past 20 years have struggled to improve survival rates.

Things once done in laboratories can now be done with computers and AI, said Kim Woo-youn, CEO and cofounder of Hits Inc. “We live in the age of ‘digital alchemy,’” Kim told BioWorld, describing how AI is shifting some drug discovery processes from physical to virtual spaces.

Gene editing can repair mutations that prematurely halt protein synthesis, resulting in incomplete peptides that cause various diseases. However, other approaches achieve the same effect without altering the genome. Startup Alltrna Inc. has developed a strategy based on transfer RNA to bypass the premature stop codons that end early protein translation. The company already has a first clinical candidate that could treat metabolic diseases such as methylmalonemia or phenylketonuria.

Peptidream Inc. has announced a preclinical development milestone in its collaboration with Alnylam Pharmaceuticals Inc. under their siRNA conjugate discovery collaboration.

Gene editing can repair mutations that prematurely halt protein synthesis, resulting in incomplete peptides that cause various diseases. However, other approaches achieve the same effect without altering the genome. Startup Alltrna Inc. has developed a strategy based on transfer RNA (tRNA) to bypass the premature stop codons that end early protein translation. The company already has a first clinical candidate that could treat metabolic diseases such as methylmalonemia (MMA) or phenylketonuria (PKU).

The first phase of the U.K. synthetic human genome project has successfully completed, realizing key steps in chromosome synthesis. The work has demonstrated a multistep method for transfecting mouse stem cells with native human chromosomes, where they are stably maintained and can be manipulated to replace native DNA with synthetic DNA. The engineered chromosomes can then be transferred into a human cell in place of the native chromosomes.

On Dec. 2, 2025, the FDA released draft guidance that could reduce the use of nonhuman primates (NHPs) in preclinical testing of monoclonal antibodies. According to the guidance, which the FDA released for the purpose of soliciting comments, “In general, studies longer than 3 months in nonrodent species (e.g., NHPs, dogs, and mini-pigs) are not warranted to evaluate toxicities … when data from 3-month studies are supplemented with a weight-of-evidence (WoE) risk assessment.”