Triana Biomedicines, a privately held biotechnology company based in Lexington, Massachusetts, has dosed the first patient in a Phase I/II clinical trial of TRI-611, an oral molecular glue degrader designed to eliminate ALK fusion proteins in patients with ALK positive NSCLC. TRI-611 is described as brain-penetrant and operates independently of the kinase active site, instead recruiting the E3 ligase cereblon to tag ALK fusion proteins for proteasomal destruction.
The global, open-label, first-in-human study will assess safety, tolerability, pharmacokinetics, and preliminary antitumor activity. The Phase I portion uses a dose-escalation design in patients previously treated with ALK tyrosine kinase inhibitors, while Phase II will evaluate efficacy across multiple patient cohorts. Specific enrollment targets, dosing schedules, and an estimated completion date have not been disclosed.
Triana has raised at least USD 120 million in Series B financing and separately signed a Pfizer collaboration with USD 49 million upfront. TRI-611 has been engineered in-house on the firm’s proprietary molecular glue discovery platform. The company’s pipeline includes earlier-stage degrader programs in breast and colorectal cancers, but TRI-611 is its only clinical-stage asset.
Research context
The rationale for degrading ALK fusion proteins rather than inhibiting their kinase activity rests on a central problem: resistance. ALK tyrosine kinase inhibitors have transformed outcomes for the roughly 3%-5% of NSCLC patients whose tumors harbor ALK rearrangements, but virtually all patients eventually progress. On-target kinase domain mutations — including compound mutations such as G1202R/L1196M — reduce TKI binding, while off-target bypass mechanisms further erode drug efficacy. Because TRI-611 engages ALK through a binding mechanism that does not depend on the ATP-binding pocket, it could, in principle, retain activity against mutations that defeat conventional inhibitors. Preclinical work on ALK-directed PROTACs has shown that degradation-based approaches can kill ALK-positive cancer cells harboring resistance mutations more effectively than inhibitors alone, and separate studies have demonstrated that disrupting ALK fusion protein function suppresses tumor growth in vitro and in vivo. More broadly, the targeted protein degradation field has been framed as a route to overcome the limitations of kinase inhibition and access previously intractable oncoproteins.
The current standard of care for ALK positive NSCLC relies on sequential ALK TKIs spanning three generations. Lorlatinib (Pfizer), the third-generation agent, received expanded first-line approval in 2021 and produced five-year progression-free survival rates of 60% in the CROWN trial. Alectinib (Genentech/Roche) gained adjuvant approval in April 2024, and ensartinib (Xcovery Holdings) was approved for first-line use in December 2024. Yet as analyses of ALK-positive patient outcomes on sequential TKI therapy have documented, resistance remains inevitable, and options after exhausting available TKIs narrow to chemotherapy. Immunotherapy has shown limited single-agent efficacy in this molecular subtype. The absence of any approved therapy operating outside the kinase-inhibition paradigm leaves a gap that degrader-based approaches aim to fill.
Competitive landscape
TRI-611 enters a field where kinase inhibitors still dominate clinical development. The most closely watched investigational agent is NVL-655 (from Nuvalent), a next-generation ALK-selective TKI designed to overcome compound resistance mutations. That molecule has FDA Breakthrough Therapy Designation for patients who have received two or more prior ALK TKIs, with pivotal data awaited. NVL-655, however, remains a kinase inhibitor and does not eliminate the ALK protein itself. SY-3505 (Shouyao Holdings) is in early-phase development for ALK positive NSCLC (SY-3505 trial), though its precise modality has not been fully clarified. Ensartinib continues in the Phase III eXalt3 trial, and lorlatinib is being evaluated in neoadjuvant settings (neoadjuvant lorlatinib trial). The field is thus bifurcating: one track seeks to engineer kinase inhibitors with broader mutational coverage, while the other — represented by TRI-611 — attempts to bypass kinase inhibition altogether through protein elimination. Whether degradation confers a durable clinical advantage over next-generation TKIs will depend on data that this TRI-611 Phase I trial is now positioned to generate.