Rentosertib UK
Investigational medicineRentosertib is an investigational medicine. It is not licensed in the UK or anywhere else, and it is not available to UK patients. A Phase III trial began in China in September 2026. More about availability in the UK.

Clinical trials

Rentosertib clinical trials

Every completed and planned clinical trial of rentosertib, with registry links, numbers of participants and what each one measured.

Seven clinical studies of rentosertib have been registered or announced since 2021. Four have finished, between them involving 205 people in Australia, New Zealand and China; none of the seven has ever had a site in the UK or Europe.

What the trial phases mean

Phase 0 gives a tiny dose, far below the amount expected to have any effect, to a handful of healthy volunteers. Its only purpose is to check how the body absorbs and clears the drug before larger doses are given.

Phase 1 gives single and then repeated doses to healthy volunteers, starting low and stepping up. It looks for side effects and measures drug levels in the blood; it is not designed to show whether a medicine works.

Phase 2 is the first test in people who have the disease. Phase 2a trials are usually small and focus on safety and dose, and they are rarely large enough to show that a treatment helps.

Phase 3 trials are large, long and randomised, and they are the studies regulators normally require before approving a medicine. They are designed in advance to answer a single main question with enough participants to give a statistically reliable answer.

Every rentosertib trial

TrialRegistry IDCountryPeopleStatusMain measure
Phase 0 microdoseACTRN12621001541897 (ANZCTR)Australia8Completed Nov 2021Drug levels and tolerability
Phase 1 single and multiple doseNCT05154240New Zealand78Completed Sept 2022Treatment-related side effects
Phase 1 ChinaCTR20221542 (chinadrugtrials.org.cn)China48CompletedSafety
Phase 2a GENESIS-IPFNCT05938920China71Completed; results posted Dec 2025Percentage with at least one side effect
Phase 2a USNCT05975983United States40 planned, 8 enrolledListed as recruiting; status unclearPercentage with at least one side effect
Phase 3 GENESIS-IPF-3NCT07687459China320 plannedFirst participant dosed Sept 2026Yearly rate of lung function decline
Phase 1 inhaledNone foundChinaAbout 80 plannedRegulator cleared Apr 2026; not startedSafety and drug levels

What is planned, and what was announced but has not happened

The Phase 3 trial in China and the inhaled Phase 1 study are the only two programmes Insilico Medicine currently describes as going ahead. Insilico expects the Phase 3 trial to finish in October 2029.

Two things announced earlier have not materialised. In June 2025 Alex Zhavoronkov, Insilico’s chief executive, said a US Phase 2b trial of more than 200 people would start in the last quarter of 2025. No such trial has been registered, and Insilico’s 2025 annual results in March 2026 did not mention it. The same interview described a China Phase 3 of more than 500 people; the trial that actually started has 320.

The authors of the Phase 2a paper also said drug-interaction studies were needed, because rentosertib appears to be broken down by liver enzymes that many other medicines use. No such study has been registered.

No UK or European sites

No rentosertib trial has ever recruited in the UK or anywhere in Europe. There is no record of an application to the Medicines and Healthcare products Regulatory Agency (MHRA) or the European Medicines Agency. The only identified UK involvement is data processing for the Phase 2a trial, carried out by Fortrea in Leeds, and an independent imaging analysis by Qureight, a Cambridge company.

The individual trials

Sources

  1. Xu Z et al. A generative AI-discovered TNIK inhibitor for idiopathic pulmonary fibrosis: a randomized phase 2a trial. Nature Medicine 2025;31:2602–2610
  2. Ren F et al. A small-molecule TNIK inhibitor targets fibrosis in preclinical and clinical models. Nature Biotechnology 2024
  3. ClinicalTrials.gov NCT05154240 (Phase 1, New Zealand)
  4. ClinicalTrials.gov NCT05938920 (Phase 2a, China)
  5. ClinicalTrials.gov NCT05975983 (Phase 2a, United States)
  6. ClinicalTrials.gov NCT07687459 (Phase 3, China)
  7. Insilico Medicine: rentosertib inhalation solution IND clearance, 28 April 2026 (company press release)
  8. Insilico Medicine: first patient dosed in GENESIS-IPF-3, September 2026 (company press release)
  9. Genetic Engineering & Biotechnology News: Insilico eyes Q4 start for late-stage trials of IPF candidate, 3 June 2025