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.

Alagille syndrome (ALGS) is a rare, multisystem genetic disorder most commonly caused by haploinsufficiency of the JAG1 gene, leading to reduced JAG1 protein function and impaired development of intrahepatic bile ducts. Researchers from Arnatar Therapeutics Inc. described the development of antisense oligonucleotides (ASOs) engineered using their proprietary ACT‑UP1 platform to upregulate endogenous JAG1 expression and thereby address the underlying genetic deficiency.

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.

BioWorld’s 2022 end-of-year highlights included a toast to the future – of universal vaccines. Even before SARS-CoV-2 vaccines were developed in record time and saved countless lives during the COVID-19 pandemic, vaccines were a rare bright spot in the fight against infectious diseases. Bacteria are becoming multidrug resistant far faster than new classes of antibiotics are being developed, viral spillover events and vector ranges are increasing, and climate change is helping bacteria and fungi alike breach human thermal protections against infections.

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.

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).

Phenylketonuria (PKU) is an autosomal recessive disorder that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems and mental disorders. This metabolic disease is caused by mutations in the phenylalanine hydroxylase (PAH) gene, resulting in patients’ inability to convert phenylalanine.

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.

A 24‑week pregnant woman fears for her unborn baby, who is developing with a sacrococcygeal teratoma so large and vascularized that it nearly surpasses the size of the fetus itself. Faced with this threat, surgeons operate inside the uterus in an open procedure that partially exposes the baby to remove the tumor and give the baby a chance to survive until birth. According to scientists presenting at the American Society of Gene & Cell Therapy's special meeting on Breakthroughs in Targeted In Vivo Gene Editing, this could be avoided.