Fruitful PROTAC Collaboration! Medicilon Assists Strategic Partner Gluetacs Therapeutics' First-in-Class RSK Dual-Functional Degrader GT818 in Receiving Clinical Trial Approval

A WSJ-style report on Gluetacs Therapeutics' first-in-class RSK dual-functional degrader GT818 receiving clinical trial approval

In the race to conquer solid tumors — which account for more than 90% of the nearly 20 million new cancer cases diagnosed globally each year — a Shanghai biotech startup has carved out a novel path. Gluetacs Therapeutics, a company born out of Shanghai University of Science and Technology, announced on July 1 that its first-in-class drug candidate GT818 has received implied clinical trial approval from China's Center for Drug Evaluation (CDE).

GT818 is a dual-functional degrader targeting RSK kinase, developed on the company's proprietary GlueTacs® protein degradation platform. The Phase I trial will evaluate its safety, tolerability, and preliminary efficacy as a monotherapy in patients with advanced malignancies, including solid tumors.

Filling a Global Void in RSK-Targeted Therapy

RSK kinase sits at a critical crossroads of multiple pro-cancer signaling pathways. Its abnormal activation has been closely linked to tumor proliferation, metastasis, and drug resistance. Yet despite its significance, no RSK-targeted degrader has been approved anywhere in the world — leaving a substantial unmet clinical need.

With GT818's approval, Gluetacs Therapeutics has officially expanded its pipeline from hematologic tumors into the far larger solid tumor arena. The company's earlier candidates, GT919 and GT929 — both molecular glue degraders — had already advanced into clinical trials for blood cancers, achieving dual IND approvals in both China and the United States.

A Five-Year Partnership Bears Fruit

Behind GT818's clinical advancement stands Shanghai Medicilon Inc. (688202.SH), a leading preclinical contract research organization founded in 2004. Since the two companies forged a strategic partnership in 2021, Medicilon has provided end-to-end preclinical research services for GT818, spanning drug discovery, pharmaceutical research, and a full suite of preclinical studies including efficacy, pharmacokinetics, and safety assessment.

GT818 marks the third PROTAC or molecular glue drug for which Medicilon has helped Gluetacs secure an IND filing — a track record that earned Medicilon the "Best Partner" award from Gluetacs Therapeutics.

Cracking the PROTAC Challenge

PROTAC molecules represent a new class of therapeutics with a dual-function structure: one end targets the protein of interest, while the other recruits an E3 ubiquitin ligase. Together, they form a ternary complex that triggers ubiquitination and degradation of the target protein. But compared with traditional small-molecule compounds, PROTACs present formidable development hurdles — longer synthetic routes, poorer druggability, and limited bioavailability in the body.

Medicilon addressed these challenges by leveraging its integrated preclinical platform, which covers everything from process optimization and formulation studies to comprehensive pharmacological evaluation. The company operates approximately 92,000 square meters of laboratory space and has served more than 2,000 clients worldwide. As of the end of 2025, Medicilon has participated in the development of 651 drug projects that received IND approval for clinical trials.

From Startup to Clinical-Stage Pipeline

Gluetacs Therapeutics was founded in February 2020 and began operations in March 2021. The company is distinguished by its dual-platform approach, owning both a molecular glue (GLUE) and a dual-functional degrader (GLUETAC) platform. It has filed and been granted more than 100 patents in the protein degradation field across multiple countries.

Today, Gluetacs has pushed three drug candidates into clinical trials, with its core pipeline now in Phase II. Its therapeutic coverage spans hematologic malignancies, solid tumors, autoimmune diseases, and rare diseases — an ambitious portfolio for a company barely five years old.

Looking Ahead

The GT818 clinical trial approval represents the latest milestone in a partnership that both companies see as a model for accelerating innovative drug development. For Medicilon, which holds GLP certifications from China's NMPA, the U.S. FDA, and the OECD, as well as AAALAC accreditation, the collaboration underscores its growing capabilities in cutting-edge modalities like PROTACs and molecular glues.

For Gluetacs, the question now is whether GT818 can deliver on the promise that RSK inhibition has long suggested but never fulfilled in the clinic. The Phase I data will offer the first real answer — and potentially open a new front in the fight against the world's most common and deadly cancers.

About Shanghai Medicilon Inc. (688202.SH): Founded in 2004, Medicilon provides comprehensive preclinical new drug R&D services for pharmaceutical companies and research institutions worldwide. The company has built an integrated R&D platform covering drug discovery, pharmaceutical research, and preclinical studies, with service capabilities in ADC, nucleic acids, peptides, CGT, PROTAC, antibodies, and other frontier fields.

About Gluetacs Therapeutics: A biotech company incubated by Shanghai University of Science and Technology, Gluetacs Therapeutics focuses on the development of oral protein degradation small-molecule drugs. The company operates dual proprietary platforms for molecular glue (GLUE) and dual-functional degraders (GLUETAC), with a differentiated pipeline covering hematologic tumors, solid tumors, autoimmune diseases, and rare diseases.