The 'AI-discovered' narrative for rentosertib, garutadustat, and REC-4881 is premature and unsupported by the current clinical evidence, which is weak, geographically limited, and lacks any competitive context. In the crowded ulcerative colitis market, the oral PHD inhibitor garutadustat enters with no disclosed data against more than ten approved therapies, including oral peer upadacitinib, which demonstrated a 39% remission difference versus placebo at week 52. [1] Similarly, the IPF asset rentosertib is advancing to a China-only Phase 3 trial without comparative data against the standard of care, nintedanib. This evidence gap is critical, as payer precedents are severe; in UC, tofacitinib required price reductions of up to 74% to meet the $50,000 per QALY threshold. [2] The historical precedent of vedolizumab's approval without direct comparator data (TA342) is a poor guide, as clinical and HTA expectations for comparative evidence have significantly drifted. Ultimately, the AI-discovery label confers no regulatory or commercial advantage. The most significant risk is that these assets are advancing based on a platform story rather than compelling clinical signals, positioning them to fail at later, more expensive stages against competitors with robust, global evidence packages.
The portfolio's lead assets are in China-only Phase 2/3 trials with no disclosed comparative efficacy or safety data, while the third relies on uncontrolled Phase 1b/2 polyp reduction data.
| Indication | Idiopathic Pulmonary Fibrosis |
| Drug | rentosertib |
| Mechanism of Action | TNIK inhibitor |
| Company | Insilico Medicine |
| Trial Phase | Phase 3 |
| Category | Clinical Trial Event |
| Sub Category | Topline Results Positive |
| Therapeutic Area | Respiratory |
| Trial Location (Rentosertib) | China |
| Follow-up Duration (Rentosertib) | 52-week |
| Secondary Drug | garutadustat |
| Secondary Indication | Inflammatory Bowel Disease |
| Secondary Drug MOA | PHD inhibitor |
| Third Drug | REC-4881 |
| Third Indication | Familial Adenomatous Polyposis |
| Third Drug MOA | MEK inhibitor |
| Key Efficacy Data (REC-4881) | 43% median reduction in polyp burden |
| Licensing Partner (REC-4881) | Takeda Pharmaceuticals |
AI-Discovered Drugs Show Mixed Results in Clinical Trials
The article examines the progress of AI-discovered drugs in clinical trials, highlighting both successes and challenges. Insilico Medicine's leading AI-designed candidate, rentosertib, a TNIK inhibitor for idiopathic pulmonary fibrosis (IPF), demonstrated improved lung function in a Phase 2 study and is now advancing to a 52-week Phase 3 trial in China. Insilico is also developing garutadustat, an oral PHD inhibitor for inflammatory bowel disease, currently in Phase 2 in China for ulcerative colitis. Recursion Pharmaceuticals' REC-4881, a MEK inhibitor for familial adenomatous polyposis (FAP), showed a 43% median reduction in polyp burden in a Phase 1b/2 trial. While AI promises to accelerate drug R&D, its ultimate impact on developing superior drugs remains an evolving question.
- Insilico Medicine's rentosertib, an AI-designed TNIK inhibitor, is progressing to a 52-week Phase 3 trial in China for idiopathic pulmonary fibrosis (IPF). This advancement follows positive results from a small Phase 2 study where the drug improved lung function, marking a significant milestone for AI-driven drug discovery in a disease with few effective treatment options.
- Insilico is also advancing garutadustat, an oral PHD inhibitor identified by AI, into Phase 2 trials in China for inflammatory bowel disease, specifically ulcerative colitis. This dual-mechanism drug aims to both reduce inflammation and repair intestinal damage, with the company positioning it as a potential best-in-class option for the condition.
- Recursion Pharmaceuticals reported positive Phase 1b/2 results for REC-4881, a MEK inhibitor in-licensed from Takeda Pharmaceuticals. Identified by AI for familial adenomatous polyposis (FAP), the drug achieved a 43% median reduction in polyp burden over three months, with sustained reductions observed even after patients discontinued medication for 12 weeks, addressing a condition currently lacking existing treatment options.
Addressing the Unmet Needs in Idiopathic Pulmonary Fibrosis with AI
Current therapeutic strategies for idiopathic pulmonary fibrosis (IPF) center on two approved antifibrotic agents, pirfenidone and nintedanib. While these drugs represent a significant advance by slowing disease progression, substantial challenges and limitations remain, leaving a high unmet need for more effective and better-tolerated treatments.
Limited Efficacy and Curative Potential: Pirfenidone and nintedanib slow the rate of lung function decline but do not reverse established fibrosis, halt disease progression entirely, or offer a cure. Consequently, IPF remains a progressive disease with a poor prognosis, and lung transplantation is still the only curative option available.
Significant Tolerability and Safety Concerns: The clinical use of both approved antifibrotics is frequently complicated by adverse events. Pirfenidone is associated with notable gastrointestinal, skin-related, and nervous system side effects, as well as potential liver function abnormalities, which can impact patient adherence and quality of life.
Unresolved Questions in Clinical Management: There is a lack of consensus on the optimal use of current therapies. Key clinical questions—including the precise indications for initiating treatment, identifying the best patient candidates, and the potential role of combination therapy—remain controversial and are not fully addressed by current guidelines.
No Demonstrated Benefit in Acute Settings: Treatment with antifibrotic medications does not appear to directly improve outcomes during acute respiratory-related hospitalizations. Studies show no effect on the need for mechanical ventilation or on 30-day mortality during or immediately following such an admission, although long-term survival may be improved in patients who survive to discharge.
Frequently Asked Questions
References
- [1] Graney BA, Lee JS. Impact of novel antifibrotic therapy on patient outcomes in idiopathic pulmonary fibrosis: patient selection and perspectives. Patient related outcome measures. 2018. 30288134
- [2] Wollin L, Distler JHW et al.. Potential of nintedanib in treatment of progressive fibrosing interstitial lung diseases. The European respiratory journal. 2019 Sep. 31285305
- [3] Ma YJ, Zhang Q et al.. The efficacy and safety of pirfenidone in the treatment of HPS-related pulmonary fibrosis and Idiopathic pulmonary fibrosis: a systematic review and meta-analysis. European review for medical and pharmacological sciences. 2022 Nov. 36459024
- [4] Kelly BT, Thao V et al.. Outcomes for hospitalized patients with idiopathic pulmonary fibrosis treated with antifibrotic medications. BMC pulmonary medicine. 2021 Jul 17. 34273943
- [5] Kishaba T, Higa M et al.. Predictors of Disease Progression in Idiopathic Pulmonary Fibrosis Under Antifibrotic Therapy: A Retrospective Study. Cureus. 2025 Dec. 41573428
- [6] Zhang HY, Pang LJ et al.. Multiple Traditional Chinese Medicine interventions for idiopathic pulmonary fibrosis: A protocol for systematic review and meta-analysis of overview. Medicine. 2020 Sep 25. 32991463
- [7] Lan YW, Chen YC et al.. Kefir peptides mitigate bleomycin-induced pulmonary fibrosis in mice through modulating oxidative stress, inflammation and gut microbiota. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2024 May. 38522238
- [8] Wang Y, Liu H et al.. Discovery of the novel Benzo[b]thiophene 1,1-dioxide derivatives as a potent STAT3 inhibitor against idiopathic pulmonary fibrosis. European journal of medicinal chemistry. 2023 Jan 15. 36463728
- [9] Cheung D, Fong A et al.. A phase 1, randomized study to evaluate safety, tolerability, and pharmacokinetics of GDC-3280, a potential novel anti-fibrotic small molecule, in healthy subjects. Pulmonary pharmacology & therapeutics. 2021 Aug. 34166834
- [10] Pesonen I, Carlson L et al.. Delay and inequalities in the treatment of idiopathic pulmonary fibrosis: the case of two Nordic countries. Multidisciplinary respiratory medicine. 2018. 29785264
- [11] Ahluwalia N, Shea BS et al.. New therapeutic targets in idiopathic pulmonary fibrosis. Aiming to rein in runaway wound-healing responses. American journal of respiratory and critical care medicine. 2014 Oct 15. 25090037
- [12] Antoniou KM, Wuyts W et al.. Medical Therapy in Idiopathic Pulmonary Fibrosis. Seminars in respiratory and critical care medicine. 2016 Jun. 27231861
- [13] Tavana S, Abedini A et al.. The effectiveness of deep lung support as an adjuvant therapy to pirfenidone on respiratory symptoms in patients with idiopathic pulmonary fibrosis: A randomized clinical trial from Iran. Respiratory medicine. 2025 Nov-Dec. 41151646
- [14] Behr J, Costabel U. [Interstitial lung diseases - historical development, current status, future prospects]. Pneumologie (Stuttgart, Germany). 2010 Sep. 20827641
- [15] Xaubet A, Molina-Molina M et al.. Guidelines for the medical treatment of idiopathic pulmonary fibrosis. Archivos de bronconeumologia. 2017 May. 28292522
- [16] Blandinières A, Gille T et al.. Endothelial Colony-Forming Cells Do Not Participate to Fibrogenesis in a Bleomycin-Induced Pulmonary Fibrosis Model in Nude Mice. Stem cell reviews and reports. 2018 Dec. 30267203
- [17] Cottin V, Crestani B et al.. Design of PROGRESSION-IPF: A pragmatic, open-label, randomized trial of patients with progressive disease in idiopathic pulmonary fibrosis. Respiratory medicine and research. 2026 May. 42025256
- [18] Xaubet A, Behr J et al.. Review of IPF diagnosis and management recommendations in Europe. Sarcoidosis, vasculitis, and diffuse lung diseases : official journal of WASOG. 2013 Dec 17. 24351616
Contact Us
Address
One Research Ct, Suite 450
Rockville, MD 20850
For General Inquiry
info@pienomial.com
