BEIJING — On 10 September, a patient at Peking Union Medical College Hospital received the first dose in a Phase III trial of a small molecule designed by software, aimed at a target that software also chose.
The setting was ordinary: a respiratory ward, a consent form. That is the news. A decade of claims about artificial intelligence in drug discovery has produced mostly slides; this programme has produced a patient and a 52-week endpoint.
The model is no longer the interesting part. The endpoint is.
Key takeaways
- Rentosertib's Phase III trial plans 320 patients at 47 centres in China over 52 weeks, with the annual rate of lung-function decline as the primary endpoint (company disclosure, 10 September 2026).
- The Phase IIa study that justified it had safety as its primary endpoint; the lung-function gain was a secondary finding in 71 patients over 12 weeks (Nature Medicine, 3 June 2025).
- Insilico Medicine has nominated 35 preclinical candidates since 2021 and holds 13 trial clearances; one asset is in Phase III (company disclosures, October 2026).
- ByteDance's spun-out Anew Labs raised US$290 million at a US$1.5 billion post-money valuation in September 2026 (Jiemian News, 12 October 2026).
- The next read-out is first-in-human safety data for a second AI-designed molecule, ISM6331, at ESMO in Madrid on 25 October 2026.
What is actually being tested
The trial is registered as NCT07687459 in the US database and CTR20262475 in China's. It is prospective, randomised, double-blind, placebo-controlled, and runs for 52 weeks. Xu Zuojun of Peking Union Medical College Hospital is the lead investigator, with Zhong Nanshan and Chen Chang as co-leads.
Three design details matter:
- The primary endpoint is the annual rate of decline in forced vital capacity (FVC, 用力肺活量), the volume a patient can force out of the lungs after a full breath.
- The key secondary endpoint is the time to a first disease-progression event.
- The population is idiopathic pulmonary fibrosis (特发性肺纤维化), a progressive scarring disease with median survival after diagnosis commonly reported at two to four years; approved antifibrotics slow it and do not reverse it.
FVC is the standard measure of progression in this disease, which is why the sponsor chose it. A drug that flattens the slope has demonstrated something a drug that improves a twelve-week reading has not.
The study that got it here measured safety
Nearly every claim about this programme traces to one paper: the Phase IIa results in Nature Medicine, 3 June 2025.
Read the design first. Seventy-one patients, four arms, twelve weeks. The primary endpoint was safety and tolerability, and it was met. The lung-function result — a mean FVC gain of 98.4 mL at the 60 mg once-daily dose, against a mean decline of 20.3 mL on placebo — was a secondary, exploratory finding in a small sample.
Insilico's own description is careful: a dose-dependent trend. That is the correct phrase. A 71-patient study of twelve weeks can generate a hypothesis and can justify a Phase III; it cannot establish efficacy. Coverage of this field often collapses those two sentences into one.
The novelty is specific. Both the target — TNIK, a kinase the investigators describe as not previously linked to fibrosis — and the molecule came out of the company's platform, and Insilico says the preclinical candidate was nominated in about 18 months after 78 molecules were synthesised.
The pipeline arithmetic
The company's disclosures say more than any single drug. Since 2021 Insilico has nominated 35 preclinical candidates, 13 of which have received or passed clinical trial applications; 11 were nominated in the first ten months of 2026 alone, and eight clinical milestones were reached by mid-August.
One of those 35 is in Phase III. That ratio is the story: discovery has become cheap enough to industrialise, and clinical validation has not.
The commercial figures need the same discipline. Insilico reported roughly US$7.3 billion of partnership value disclosed in 2026 through mid-August, taking the cumulative total since 2021 to near US$11 billion. These are "up to" figures — milestone schedules contingent on events that have not occurred — not revenue and not cash.
Anew Labs, the drug-discovery team ByteDance spun out in June 2026, closed a US$290 million first round in September at a US$1.5 billion post-money valuation, with ByteDance retaining 56% (Jiemian News, 12 October 2026).
Why the trial runs in China
The 47 Phase III centres are all in China, per the company's announcement. That is an operational choice with a cost. A single-country design is simpler to run, but it gives regulators in Washington and Brussels a narrower basis for extrapolation, because background therapy and patient mix differ from the populations those agencies review.
China's trial infrastructure is also why a company this size can run such a study at all.
The next data point
On 25 October at the European Society for Medical Oncology congress in Madrid, investigators present abstract 997: first-in-human data for ISM6331, an oral pan-TEAD inhibitor designed with the same chemistry platform, in mesothelioma and other advanced solid tumours.
It is a Phase I: dose, pharmacokinetics, safety and at best an early response signal. It cannot show that the platform works. Read it as a manufacturing check on a second molecule, not as confirmation of the first.
Honest limitations
Pipeline counts and partnership values are company disclosures and are not audited; "up to" totals should never be read as booked revenue. The Phase IIa evidence is small, short and drawn from one country, and its lung-function effect was a secondary endpoint, so the Phase III can still fail. The "world's first" descriptions are Insilico's own characterisation, not a regulatory finding. This column found no independent replication of the Phase IIa result. The ESMO abstract had not been presented when this was written.
What readers can do now
- Analysts: check NCT07687459 quarterly against the 320-patient target. Enrolment pace is the earliest public signal on whether the 2029 read-out holds.
- Licensing teams: when a deal value is quoted, ask for the split between upfront payment, near-term milestones and the tail. The headline total is a marketing number until the schedule is disclosed.
- Newsrooms: establish which part of a programme was machine-derived — target, molecule, or only optimisation. Here it is the first two, which is still rare, and saying so is more useful than "AI drug".