Glossary

Acute exacerbation A sudden, severe worsening of IPF over days or weeks, usually needing hospital admission. It is often fatal.

Adverse event Any medical problem that happens during a trial, whether or not the medicine caused it. Those judged likely to be caused by it are reported as treatment-related.

Antifibrotic A medicine that aims to slow the scarring of lung tissue. Pirfenidone and nintedanib are the two established on the NHS for IPF.

ATS / ERS The American Thoracic Society and the European Respiratory Society, the two largest lung-medicine bodies. They publish the international IPF guidelines jointly.

Biomarker Something measurable in the body, such as a blood protein, used as a stand-in for how a disease or treatment is behaving.

Breakthrough Therapy Designation A status that speeds a regulator’s review of a medicine for a serious condition. It is not an approval. China’s regulator gave rentosertib it in May 2025.

CDE The Center for Drug Evaluation, the part of China’s medicines regulator that assesses new medicines. It oversees all of rentosertib’s current trials.

Confidence interval The range the true result is likely to fall within, usually given as 95%. A range crossing zero is compatible with no effect.

DLCO Diffusing capacity for carbon monoxide, a breathing test of how well oxygen passes from the lungs into the blood.

Double-blind A trial in which neither the participants nor the staff treating them know who is getting the medicine and who is getting placebo.

FDA The United States medicines regulator, which gave rentosertib an orphan drug designation in February 2023.

FVC Forced vital capacity, a measure of how much air you can breathe out in one big breath. It is the main measure used in IPF trials, given in millilitres or as a percentage of what is expected for your age, sex and height.

GENESIS-IPF The phase 2a trial of rentosertib run in China in 2023 and 2024 in 71 people with IPF. The phase 3 trial begun in September 2026 is GENESIS-IPF-3.

Half-life The time it takes for the amount of a medicine in the blood to halve. Rentosertib’s was measured at roughly 7 to 12 hours.

HRCT High-resolution computed tomography, a detailed CT scan of the lungs and the main test used to diagnose IPF.

ILD Interstitial lung disease, an umbrella term for conditions that inflame or scar the tissue between the air sacs of the lungs. IPF is one of them.

ILD centre A specialist NHS hospital service for interstitial lung disease. In England, antifibrotics can only be started at one of roughly 23 to 24 commissioned centres.

IND Investigational New Drug application, the permission a regulator must give before a new medicine can be tested in people.

IPF Idiopathic pulmonary fibrosis, in which lung tissue scars progressively for reasons that are not known. About 30,000 people in the UK live with it, with around 6,000 new diagnoses a year.

K-BILD The King’s Brief Interstitial Lung Disease questionnaire, measuring how the condition affects daily life. It is a phase 3 secondary measure.

L-PF The Living with Pulmonary Fibrosis questionnaire, which asks about symptoms and their impact. It is also a phase 3 secondary measure.

LCQ The Leicester Cough Questionnaire, which measures how much a persistent cough affects someone’s life.

Marketing authorisation The licence a medicine needs before it can be sold or supplied in a country. Rentosertib has none anywhere.

MHRA The Medicines and Healthcare products Regulatory Agency, the UK medicines regulator. It grants licences, runs Yellow Card and enforces the rules on advertising medicines.

NICE The National Institute for Health and Care Excellence, which decides whether the NHS in England funds a licensed medicine. A licence alone does not get a medicine onto the NHS.

Nintedanib An antifibrotic capsule licensed for IPF and recommended by NICE in 2016. It needs regular liver blood tests, and diarrhoea is a common side effect.

Once daily / twice daily How often a dose is taken. Trial reports sometimes abbreviate these as QD and BID.

Orphan drug designation A status given to a medicine for a rare disease, bringing incentives such as fee reductions. It says nothing about whether the medicine works.

PandaOmics and Chemistry42 Insilico Medicine’s two software platforms. PandaOmics picked TNIK as a target from biological data; Chemistry42 designed candidate molecules.

Phase 0, 1, 2, 3 The stages of testing in people: a tiny dose in a few volunteers (0), safety and dosing in healthy volunteers (1), early signs of effect in people with the disease (2), and the large trial designed to prove it works (3).

Pirfenidone The other antifibrotic established on the NHS for IPF, recommended by NICE in 2018. England and Scotland apply different lung-function criteria to it.

Placebo A dummy treatment with no active medicine in it, used so the real medicine can be compared fairly.

PPF Progressive pulmonary fibrosis, a term for other scarring lung diseases that worsen the way IPF does. It is a different group of people.

Primary endpoint The main question a trial is designed to answer, fixed before it starts. Everything else it measures is secondary and weaker evidence.

Proteomic ageing clock A model that predicts a person’s age from the proteins in their blood. The gap from their real age is called “biological age”, but it reflects illness as well as ageing.

Randomised Allocated to a trial group by chance, so the groups being compared start out as similar as possible.

SMC The Scottish Medicines Consortium, which decides which licensed medicines NHS Scotland funds. Its antifibrotic rules differ from NICE’s.

TEAE Treatment-emergent adverse event, any adverse event appearing after a person starts the study medicine. The proportion with at least one was the phase 2a primary endpoint.

TNIK TRAF2 and NCK-interacting kinase, an enzyme in the signals that drive tissue scarring. It is the target rentosertib is designed to block.

UIP Usual interstitial pneumonia, the pattern of scarring on a CT scan or in lung tissue that points to a diagnosis of IPF.

USAN / INN The official generic names given to a medicine. “Rentosertib” was adopted in March 2025, replacing the codes ISM001-055 and INS018_055.

Yellow Card The MHRA scheme through which anyone in the UK can report a suspected side effect of a licensed medicine. It does not apply to rentosertib, which has no UK licence.