Conventional mouse models are not susceptible to hepatitis A virus (HAV) because murine adaptor protein MAVS is not efficiently cleaved by HAV protease precursors, so intact type I interferon (IFN) signaling blocks productive infection. However, IFN receptor knockout (KO) mice are susceptible to HAV infection and show hallmark features of the infection, having recently been identified as a potential disease model. Researchers from Genematrix Inc. aimed to determine whether nonclinical efficacy studies can be performed in small animal models.

The U.K. Medicines and Healthcare products Regulatory Agency (MHRA) is to offer an early review of nonanimal data to give companies more confidence that evidence generated with new approach methodologies, such as organoids and microphysiological systems, will be accepted as part of marketing authorization applications.

In what the U.S. FDA has dubbed a milestone move toward fewer animal studies in drug development, the agency published a draft guidance to help sponsors validate new approach methodologies that can bring safe, effective drugs to market sooner based on human-centric data rather than starting off with nonclinical animal pharmacology and toxicology data.

Approximately 10%-15% of breast cancer cases are classified within the invasive lobular carcinoma (ILC) type, and a great majority of them are estrogen receptor-positive (ER+). Despite the significant clinical differences between ILCs and invasive carcinoma of no special type (or ductal), ICL treatment still follows ductal paradigms, relying on endocrine therapy plus surgery and radiotherapy.

Friedreich’s ataxia (FA), the most common form of hereditary ataxia, is an autosomal recessive neurodegenerative disorder affecting multiple organ systems, and causing cardiomyopathy, scoliosis, muscle weakness, speech impairment and other systemic issues.

Scientists at Ghent University have created a mouse model that incorporates human versions of the receptors that recognize the fragment crystallizable region of immunoglobulin G, one of the most abundant antibodies in the blood and a key mediator of essential immune functions such as cellular activation, pathogen elimination and the regulation of inflammatory responses.

Scientists at Ghent University have created a mouse model that incorporates human versions of the receptors that recognize the fragment crystallizable (Fc) region of immunoglobulin G (IgG), one of the most abundant antibodies in the blood and a key mediator of essential immune functions such as cellular activation, pathogen elimination and the regulation of inflammatory responses. These human Fcγ receptors allow the humanized mouse to more accurately reproduce IgG-driven biology, enabling more reliable and safer preclinical assays before evaluating monoclonal antibodies in clinical trials with people.

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.”

The U.K. government has published a road map for phasing out animal testing in life sciences research and announced £75 million (US$98.6 million) for work to develop nonanimal models, leaving scientists concerned because they say, in many cases, there can never be meaningful alternatives to using live animals.