Cedars-Sinai Continues Phase 2 Enrollment for Ketogenic Diet in Glioblastoma Study
Clinical Design and Progress
The DIET2TREAT study, led by Cedars-Sinai Medical Center, is a randomized, multi-center Phase 2 clinical trial enrolling 170 newly diagnosed glioblastoma patients. It commenced on June 27, 2023, and is currently recruiting, as updated on ClinicalTrials.gov on May 6, 2026. Patients are randomized 1:1 to either a ketogenic diet or a standard-of-care diet based on guidelines from the American Society of Clinical Oncology and the American Cancer Society. The dietary intervention is administered for 18 weeks, concurrent with the start of chemoradiation. The primary completion date is projected for September 30, 2028, and the overall completion date is September 30, 2029, necessitating long-term follow-up to assess survival outcomes for investment considerations.
Rationale for Metabolic Intervention
The ketogenic diet group follows a 3:1 ratio of fat to combined carbohydrates and protein, with daily monitoring of blood ketone and glucose levels to ensure adherence. This non-pharmacological adjunctive strategy aims to restrict glycolysis in glucose-dependent glioblastoma cells and create a ketogenic metabolic environment. The primary endpoint is overall survival (OS), and all patients receive standard treatment, allowing for comparison of the additional effect of the diet. Given that prior studies have primarily focused on small-scale safety and feasibility assessments, this 170-patient randomized design represents a critical step in establishing the clinical validity of metabolic therapy.
Competitive Landscape with Standard Treatment
The current standard of care involves maximal safe surgical resection followed by radiation therapy and concurrent temozolomide (Temodar), followed by maintenance therapy. Temozolomide is an alkylating agent that methylates the O6 and N7 positions of guanine in DNA. The U.S. FDA initially approved temozolomide in 1999 and updated the label for new combination and maintenance treatment for glioblastoma on September 14, 2023. Novocure (NVCR)'s Optune is a medical device that uses Tumor Treating Fields (TTFields) to disrupt mitosis, and the FDA approved its use in combination with temozolomide for newly diagnosed glioblastoma on October 5, 2015. For recurrent patients, Roche (ROG)'s Avastin (bevacizumab) targets vascular endothelial growth factor A (VEGF-A) and is a key comparative treatment that received accelerated approval from the FDA on May 2009.
Market Potential and Business Implications
The global glioblastoma market was estimated at approximately USD 3.23 billion in 2025, and the need for new combination strategies is growing due to high recurrence rates and limited survival improvements. The ketogenic diet is not a patented drug, so business opportunities are more likely to arise in areas such as oncology nutrition management, remote adherence monitoring, and blood glucose/ketone monitoring services, rather than direct new drug sales. However, the lifestyle intervention nature of the diet may weaken efficacy signals due to patient adherence, weight loss and nutritional deficiencies, and variations in dietary management across institutions. Significant OS improvement would support progression to Phase 3 trials and consideration for inclusion in clinical guidelines, but the current study is in the Phase 2 recruitment stage with no results reported, which is a key limitation for valuation.
This study is a 170-patient Phase 2 trial investigating whether overall survival can be improved without adding drugs in the approximately USD 3.23 billion glioblastoma market in 2025. In the short term, the feasibility of the trial will depend on blood ketone/glucose management and 18-week dietary adherence until the primary completion date of September 2028. In the medium to long term, significant OS improvement would provide evidence to add low-cost metabolic intervention to the standard of care centered on Temodar and Novocure (NVCR)'s Optune. For researchers, this is a randomized dataset to validate the causality of tumor metabolic regulation, and for the nutrition management and digital monitoring industries, it could open up a market for supportive care as a service. However, it is not a patentable new drug and requires Phase 3 confirmation, so a Watchlist approach is appropriate from an investment perspective.
Source: ClinicalTrials.gov (api_ct)