On November 11, 2024 Gritstone bio, Inc. (OTC: GRTSQ), a clinical-stage biotechnology company working to develop the world’s most potent vaccines, reported encouraging updated interim Phase 2 data from the ongoing Phase 2 study evaluating GRANITE, its individualized neoantigen targeting immunotherapy, in first-line microsatellite stable colorectal cancer (MSS-CRC) (Press release, Gritstone Bio, NOV 11, 2024, View Source [SID1234648070]). The ongoing randomized, controlled study is evaluating the clinical benefit of maintenance therapy with GRANITE (GRT-C901/GRT-R902) in combination with immune checkpoint inhibitors (ICI) in addition to fluoropyrimidine/bevacizumab versus fluoropyrimidine/bevacizumab alone.
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
"Our encouraging Phase 2 data for GRANITE in MSS-CRC continue to mature and demonstrate durable benefit over time. With two additional months of follow-up, relative progression-free survival has further improved in the analysis of all patients treated with GRANITE, and most notably, in those with a lower tumor burden at study baseline," said Andrew Allen, MD, PhD, Co-founder, President & CEO of Gritstone bio. "The powerful anti-tumor immunity induced by GRANITE in an immunologically cold tumor setting like MSS-CRC underscores a differentiated approach with a multitude of expansion opportunities across solid tumor indications. Moreover, these data also further de-risk SLATE, our off-the-shelf cancer immunotherapy program, and more importantly, reinforce the transformative potential of Gritstone’s overall immunotherapy platform."
Dr. Allen continued, "We are focused on our mission to deliver potentially life-saving treatments like GRANITE to millions of patients worldwide and continue to explore several strategic and funding alternatives during the financial restructuring process. The compelling progression-free survival data in a challenging disease context, coupled with a well-tolerated safety profile, supports further continuation of the GRANITE program by a party who shares our vision to deliver novel treatments leveraging the immune response to fight tough to treat cancers."
Key Findings from an Updated Interim Phase 2 Analysis in Front-Line Metastatic MSS-CRC
Data cut as of October 17, 2024 vs. August 19, 2024
An updated October analysis of progression-free survival (PFS) per RECIST v1.1 included an additional two months of follow-up.
28% (11/39) GRANITE and 13% (4/30) of control patients remain on study and free of progression vs. 33% (13/39) GRANITE and 23% (7/30) of control patients from August analysis; the majority of GRANITE patients still on study have undetectable ctDNA using Gritstone’s high-sensitivity, tumor-informed assay
Clinical benefit improved compared to previous analysis in patients with low and high disease burden (based on ctDNA levels)
Clinical benefit was most notable in patients with low disease burden at study entry
Low baseline ctDNA levels (eg at study entry) is a likely prognostic and predictive factor
Overall survival data remain immature, with mature data expected in 2H 2025
GRANITE continues to demonstrate a favorable safety and tolerability profile
Summary of Progression-Free Survival Results
Relative Risk Reduction;
PFS Hazard Ratio*
October Analysis 2024 August Analysis 2024
All patients
n = 69 27%;
0.73, [90% CI, 0.44-1.21] 21%;
0.79, [90% CI, 0.47-1.35]
ctDNA-lo^
n = 31 50%;
0.5, [90% CI, 0.20-1.28] 43%;
0.57, [90% CI, 0.20-1.58]
ctDNA-hi^
n = 30 22%;
0.78, [90% CI, 0.39-1.58] 13%;
0.87, [90% CI, 0.41- 1.86]
*The protocol-defined PFS analysis (per RECIST v1.1) is reported herein for all groups. An exploratory analysis using both radiographic and clinical progression data was reported for the ctDNA subgroups on September 30, 2024.
^Not all patients had baseline samples for analysis
Restructuring Process
On October 10, 2024, Gritstone filed a voluntary petition under chapter 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the District of Delaware (the "Court".) During its financial restructuring process, Gritstone intends to operate in the ordinary course and remains committed to advancing its clinical programs, including its ongoing neoantigen immunotherapy and infectious disease programs, and driving innovation in immunotherapy and vaccine development.
Gritstone is continuing its sale process and actively pursuing bidders for all or any portion of the Company’s assets to continue research and development of its next-generation vaccines and immunotherapies for oncology and infectious diseases. The bid deadline for the sale process is December 4, 2024. For more information, please reach out to [email protected].
About the GO-010 Study
GO-010 (NCT05141721) is a Phase 2, randomized, open-label study designed to evaluate the clinical benefit of maintenance therapy with GRANITE (GRT-C901/GRT-R902), a neoantigen targeting immunotherapy, in combination with immune checkpoint inhibitors (ICI) in addition to fluoropyrimidine/bevacizumab versus fluoropyrimidine/bevacizumab alone in patients with first-line microsatellite stable colorectal cancer (MSS-CRC). 104 patients were randomized 1:1 in the study: 69 patients (39 GRANITE arm, 30 control arm) are included in the treated analysis above. Demographics and clinical characteristics were balanced between arms (e.g., stage, sidedness, presence of liver metastases), with the vast majority (80%) of patients having liver metastases in the treated analysis. Thirty-five patients did not advance to study treatment after oxaliplatin most commonly due to withdrawing consent (n=15), disease progression (n=7), and other reasons (n=13) (12 in GRANITE arm; 23 in control arm).