ivosidenib and Glioma

Vorasidenib and ivosidenib inhibit mutant forms of isocitrate dehydrogenase (mIDH) and have shown preliminary clinical activity against mIDH glioma. We evaluated both agents in a perioperative phase 1 trial to explore the mechanism of action in recurrent low-grade glioma (IGG) and select a molecule for phase 3 testing. Primary end-point was concentration of D-2-hydroxyglutarate (2-HG), the metabolic product of mIDH enzymes, measured in tumor tissue from 49 patients with mIDH1-R132H nonenhancing gliomas following randomized treatment with vorasidenib (50 mg or 10 mg once daily, q.d.), ivosidenib (500 mg q.d. or 250 mg twice daily) or no treatment before surgery. Tumor 2-HG concentrations were reduced by 92.6% (95% credible interval (CrI), 76.1-97.6) and 91.1% (95% CrI, 72.0-97.0) in patients treated with vorasidenib 50 mg q.d. and ivosidenib 500 mg q.d., respectively. Both agents were well tolerated and follow-up is ongoing. In exploratory analyses, 2-HG reduction was associated with increased DNA 5-hydroxymethylcytosine, reversal of 'proneural' and 'stemness' gene expression signatures, decreased tumor cell proliferation and immune cell activation. Vorasidenib, which showed brain penetrance and more consistent 2-HG suppression than ivosidenib, was advanced to phase 3 testing in patients with mIDH LGGs. Funded by Agios Pharmaceuticals, Inc. and Servier Pharmaceuticals LLC; ClinicalTrials.gov number NCT03343197.

Topics: Brain Neoplasms; Glioma; Humans; Isocitrate Dehydrogenase; Mutation; Pharmaceutical Preparations; Pyridines

Since IDH-mutant (mIDH) low-grade gliomas (LGGs) progress slowly and have a relatively long survival, there is a significant need for earlier measurements of clinical benefit. Guidance using the LGG RANO criteria recommends serial bidirectional (2D) measurements on a single slice; however, questions remain as to whether volumetric (3D) measurements are better, since they would allow for more accurate measurements in irregular shaped lesions and allow readers to better assess areas of subtle change.. Twenty-one (out of 24) non-enhancing, recurrent mIDH1 LGGs were enrolled in a phase I, multicenter, open-label study of oral ivosidenib (NCT02073994), and with imaging pre- and post-treatment as part of this exploratory ad hoc analysis. 2D and 3D measurements on T2-weighted FLAIR images were centrally evaluated at an imaging contract research organization using a paired read and forced adjudication paradigm. The effects of 2D vs 3D measurements on progression-free survival (PFS), growth rate measurement variability, and reader concordance and adjudication rates were quantified.. 3D volumetric measurements showed significantly longer estimated PFS (P = .0181), more stable (P = .0063) and considerably slower measures of tumor growth rate (P = .0037), the highest inter-reader agreement (weighted kappa = 0.7057), and significantly lower reader discordance rates (P = .0002) with 2D LGG RANO.. 3D volumetric measurements are better for determining response assessment in LGGs due to more stable measures of tumor growth rates (ie, less "yo-yo-ing" of measurements over time), highest inter-reader agreement, and lowest reader discordance rates. Continued evaluation in future studies is warranted to determine whether these measurements reflect clinical benefit.

Topics: Brain Neoplasms; Glioma; Glycine; Humans; Isocitrate Dehydrogenase; Magnetic Resonance Imaging; Pyridines

Diffuse gliomas are malignant brain tumors that include lower-grade gliomas (LGGs) and glioblastomas. Transformation of low-grade glioma into a higher tumor grade is typically associated with contrast enhancement on magnetic resonance imaging. Mutations in the isocitrate dehydrogenase 1 (. We conducted a multicenter, open-label, phase I, dose escalation and expansion study of ivosidenib in patients with m. In 66 patients with advanced gliomas, ivosidenib was well tolerated, with no dose-limiting toxicities reported. The maximum tolerated dose was not reached; 500 mg once per day was selected for the expansion cohort. The grade ≥ 3 adverse event rate was 19.7%; 3% (n = 2) were considered treatment related. In patients with nonenhancing glioma (n = 35), the objective response rate was 2.9%, with 1 partial response. Thirty of 35 patients (85.7%) with nonenhancing glioma achieved stable disease compared with 14 of 31 (45.2%) with enhancing glioma. Median progression-free survival was 13.6 months (95% CI, 9.2 to 33.2 months) and 1.4 months (95% CI, 1.0 to 1.9 months) for the nonenhancing and enhancing glioma cohorts, respectively. In an exploratory analysis, ivosidenib reduced the volume and growth rates of nonenhancing tumors.. In patients with m

Topics: Adult; Aged; Antineoplastic Agents; Brain Neoplasms; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Glioma; Glycine; Humans; Isocitrate Dehydrogenase; Male; Middle Aged; Mutation; Pyridines; Young Adult

Isocitrate dehydrogenase (IDH)-mutant gliomas are usually treated with radiotherapy and chemotherapy, which increases the risk for neurocognitive sequelae during patients' most productive years. We report our experience using off-label first-in-class mutant IDH1 inhibitor ivosidenib and its impact on tumor volume in IDH-mutant gliomas.. We retrospectively analyzed patients ages ≥18 years with radiation/chemotherapy-naïve, mutant IDH1, nonenhancing, radiographically active, grade 2/3 gliomas, and ≥2 pretreatment and ≥2 on-treatment ivosidenib MRIs. T2/FLAIR-based tumor volumes, growth rates, and progression-free survival (PFS) were analyzed. log-linear mixed-effect modeling of growth curves adjusted for grade, histology, and age was performed.. We analyzed 116 MRIs of 12 patients [10 males, median age 46 years (range: 26-60)]: 8 astrocytomas (50% grade 3) and 4 grade 2 oligodendrogliomas. Median on-drug follow-up was 13.2 months [interquartile range (IQR): 9.7-22.2]. Tolerability was 100%. A total of 50% of patients experienced ≥20% tumor volume reduction on-treatment and absolute growth rate was lower during treatment (-1.2 ± 10.6 cc/year) than before treatment (8.0 ± 7.7 cc/year; P ≤ 0.05). log-linear models in the Stable group (n = 9) showed significant growth before treatment (53%/year; P = 0.013), and volume reduction (-34%/year; P = 0.037) after 5 months on treatment. After treatment, volume curves were significantly lower than before treatment (after/before treatment ratio 0.5; P < 0.01). Median time-to-best response was 11.2 (IQR: 1.7-33.4) months, and 16.8 (IQR: 2.6-33.5) months in patients on drug for ≥1 year. PFS at 9 months was 75%.. Ivosidenib was well tolerated and induced a high volumetric response rate. Responders had significant reduction in tumor growth rates and volume reductions observed after a 5-month delay. Thus, ivosidenib appears useful to control tumor growth and delay more toxic therapies in IDH-mutant nonenhancing indolently growing gliomas. See related commentary by Lukas and Horbinski, p. 4709.

Topics: Brain Neoplasms; Glioma; Humans; Isocitrate Dehydrogenase; Male; Middle Aged; Mutation; Retrospective Studies

Topics: Glioma; Glycine; Humans; Pyridines

Mutations in isocitrate dehydrogenase 1 (IDH1mut) are reported in 70-90% of low-grade gliomas and secondary glioblastomas. IDH1mut catalyzes the reduction of α-ketoglutarate (α-KG) to 2-hydroxyglutarate (2-HG), an oncometabolite which drives tumorigenesis. Inhibition of IDH1mut is therefore an emerging therapeutic approach, and inhibitors such as AG-120 and AG-881 have shown promising results in phase 1 and 2 clinical studies. However, detection of response to these therapies prior to changes in tumor growth can be challenging. The goal of this study was to identify non-invasive clinically translatable metabolic imaging biomarkers of IDH1mut inhibition that can serve to assess response.

Topics: Antineoplastic Agents; Biomarkers, Tumor; Brain Neoplasms; Carbon-13 Magnetic Resonance Spectroscopy; Cell Line, Tumor; Diamines; Glioma; Glutamic Acid; Glutarates; Glycine; Humans; Isocitrate Dehydrogenase; Mutation; Proton Magnetic Resonance Spectroscopy; Pyridines

Isocitrate dehydrogenase 1 (IDH1), which catalyzes the conversion of isocitrate to α-ketoglutarate, is one of key enzymes in the tricarboxylic acid cycle (TCA). Hotspot mutation at Arg

Topics: Animals; Antineoplastic Agents; Blood-Brain Barrier; Brain Neoplasms; Cell Proliferation; Dose-Response Relationship, Drug; Drug Discovery; Drug Screening Assays, Antitumor; Female; Glioma; Humans; Isocitrate Dehydrogenase; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Structure; Neoplasms, Experimental; Small Molecule Libraries; Structure-Activity Relationship; Tumor Cells, Cultured