The U.S. Food and Drug Administration (FDA) has cleared the Investigational New Drug (IND) application for GS-6791/NX-0479, a novel IRAK4 degrader developed through a collaboration between Nurix Therapeutics and Gilead Sciences. This regulatory milestone enables the initiation of a Phase 1 clinical trial, expected to begin in the second quarter of 2025.
Gilead Sciences plans to conduct a Phase 1 study evaluating both single ascending dose (SAD) and multiple ascending dose (MAD) regimens in healthy volunteers. The clearance triggers a $5 million milestone payment to Nurix, bringing the total amount received under their 2019 collaboration agreement to $135 million.
GS-6791/NX-0479 represents a significant advancement in targeted protein degradation technology, specifically designed to address inflammatory conditions with high unmet medical needs. The compound works by degrading IRAK4, a critical regulator of inflammatory signaling pathways.
Mechanism of Action and Preclinical Evidence
"GS-6791/NX-0479 is a highly optimized, selective, oral degrader of IRAK4, a master regulator of IL-1R/TLR signaling pathways that plays a crucial role in inflammatory processes," explained Gwenn M. Hansen, Ph.D., chief scientific officer of Nurix. "IRAK4 has both kinase and scaffolding functions, thus complete pathway blockade requires an innovative approach like targeted protein degradation."
The scientific rationale for targeting IRAK4 through degradation rather than inhibition stems from the protein's dual functionality. By completely removing the protein rather than merely blocking its kinase activity, GS-6791/NX-0479 potentially offers more comprehensive pathway suppression.
Preclinical studies have demonstrated promising results, including:
- Rapid and potent IRAK4 degradation across multiple human cell types in vitro
- Rapid and sustained degradation in non-human primates
- Complete IRAK4 degradation and cytokine suppression in disease-relevant tissues such as synovial fibroblasts and keratinocytes
- Robust efficacy in rodent models of arthritis
These findings suggest potential applications across multiple inflammatory conditions, particularly rheumatoid arthritis and atopic dermatitis, representing significant market opportunities in both rheumatology and dermatology.
Strategic Collaboration and Financial Terms
The development of GS-6791/NX-0479 stems from a global strategic collaboration established in June 2019 between Gilead Sciences and Nurix Therapeutics. The partnership focuses on discovering, developing, and commercializing up to five innovative targeted protein degradation therapies.
Arthur T. Sands, M.D., Ph.D., president and chief executive officer of Nurix, highlighted the significance of this milestone: "Today's announcement highlights the continuing success and productivity of our collaboration with Gilead and demonstrates Nurix's ability to advance potential best-in-class degrader-based medicines for patients suffering from inflammation and autoimmune diseases."
Under the terms of the agreement, Nurix received an upfront payment of $45 million and was eligible for success-based preclinical milestones totaling $15 million, along with a licensing fee of $20 million. With the $5 million payment for IND clearance, Nurix remains eligible for $420 million in potential future development, regulatory, and commercial milestone payments associated with the IRAK4 degrader program, as well as up to low double-digit tiered royalties on net sales.
Importantly, Nurix retains an option to co-develop and co-detail the program in the United States following completion of Phase 1 clinical trials. If exercised, the parties would split development costs as well as profits and losses 50/50 for the U.S. market, with Nurix receiving royalties on ex-U.S. sales and reduced milestone payments.
Broader Pipeline and Company Focus
GS-6791/NX-0479 represents one component of Nurix's expanding portfolio of degrader-based medicines targeting inflammatory and autoimmune diseases. The company's pipeline includes:
- A STAT6 degrader in collaboration with Sanofi
- A proprietary BTK degrader (NX-5948) for inflammation and autoimmune diseases
- Multiple degraders and degrader antibody conjugates (DACs) in preclinical development
Nurix Therapeutics, headquartered in San Francisco, has established itself as a leader in the emerging field of targeted protein degradation. The company employs an AI-integrated discovery engine capable of addressing any protein class, combined with extensive ligase expertise, positioning it at the forefront of this innovative therapeutic approach.
Market Potential and Future Outlook
The successful development of GS-6791/NX-0479 could address significant unmet needs in inflammatory disease treatment. Rheumatoid arthritis affects approximately 1.3 million Americans and 14 million people worldwide, while atopic dermatitis impacts over 16.5 million adults in the United States alone.
Current treatments for these conditions often have limitations in efficacy, safety profiles, or convenience. A novel oral therapy with a differentiated mechanism of action could potentially offer advantages over existing options, particularly for patients who do not respond adequately to current standards of care.
As the program advances into clinical development, key milestones to watch include initial safety and pharmacokinetic data from the Phase 1 trial, potential expansion into patient populations, and any signals of efficacy in inflammatory conditions. The collaboration between Nurix and Gilead represents a significant step forward in bringing innovative targeted protein degradation approaches to patients with inflammatory and autoimmune diseases.
