Final Overall Survival Efficacy Results of Ivosidenib for Patients With Advanced Cholangiocarcinoma With IDH1 Mutation: The Phase 3 Randomized Clinical ClarIDHy Trial

IMPORTANCE: Isocitrate dehydrogenase 1 (IDH1) variations occur in up to approximately 20% of patients with intrahepatic cholangiocarcinoma. In the ClarIDHy trial, progression-free survival as determined by central review was significantly improved with ivosidenib vs placebo. OBJECTIVE: To report the final overall survival (OS) results from the ClarIDHy trial, which aimed to demonstrate the efficacy of ivosidenib (AG-120)—a first-in-class, oral, small-molecule inhibitor of mutant IDH1—vs placebo for patients with unresectable or metastatic cholangiocarcinoma with IDH1 mutation. DESIGN, SETTING, AND PARTICIPANTS: This multicenter, randomized, double-blind, placebo-controlled, clinical phase 3 trial was conducted from February 20, 2017, to May 31, 2020, at 49 hospitals across 6 countries among patients aged 18 years or older with cholangiocarcinoma with IDH1 mutation whose disease progressed with prior therapy. INTERVENTIONS: Patients were randomized 2:1 to receive ivosidenib, 500 mg, once daily or matched placebo. Crossover from placebo to ivosidenib was permitted if patients had disease progression as determined by radiographic findings. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival as determined by blinded independent radiology center (reported previously). Overall survival was a key secondary end point. The primary analysis of OS followed the intent-to-treat principle. Other secondary end points included objective response rate, safety and tolerability, and quality of life. RESULTS: Overall, 187 patients (median age, 62 years [range, 33-83 years]) were randomly assigned to receive ivosidenib (n = 126; 82 women [65%]; median age, 61 years [range, 33-80 years]) or placebo (n = 61; 37 women [61%]; median age, 63 years [range, 40-83 years]); 43 patients crossed over from placebo to ivosidenib. The primary end point of progression-free survival was reported elsewhere. Median OS was 10.3 months (95% CI, 7.8-12.4 months) with ivosidenib vs 7.5 months (95% CI, 4.8-11.1 months) with placebo (hazard ratio, 0.79 [95% CI, 0.56-1.12]; 1-sided P = .09). When adjusted for crossover, median OS with placebo was 5.1 months (95% CI, 3.8-7.6 months; hazard ratio, 0.49 [95% CI, 0.34-0.70]; 1-sided P < .001). The most common grade 3 or higher treatment-emergent adverse event (≥5%) reported in both groups was ascites (11 patients [9%] receiving ivosidenib and 4 patients [7%] receiving placebo). Serious treatment-emergent adverse events considered ivosidenib related were reported in 3 patients (2%). There were no treatment-related deaths. Patients receiving ivosidenib reported no apparent decline in quality of life compared with placebo. CONCLUSIONS AND RELEVANCE: This randomized clinical trial found that ivosidenib was well tolerated and resulted in a favorable OS benefit vs placebo, despite a high rate of crossover. These data, coupled with supportive quality of life data and a tolerable safety profile, demonstrate the clinical benefit of ivosidenib for patients with advanced cholangiocarcinoma with IDH1 mutation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT0298985

Mutant IDH inhibits HNF-4α to block hepatocyte differentiation and promote biliary cancer

Mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 are among the most common genetic alterations in intrahepatic cholangiocarcinoma (IHCC), a deadly liver cancer1, 2, 3, 4, 5. Mutant IDH proteins in IHCC and other malignancies acquire an abnormal enzymatic activity allowing them to convert α-ketoglutarate (αKG) to 2-hydroxyglutarate (2HG), which inhibits the activity of multiple αKG-dependent dioxygenases, and results in alterations in cell differentiation, survival, and extracellular matrix maturation6, 7, 8, 9, 10. However, the molecular pathways by which IDH mutations lead to tumour formation remain unclear. Here we show that mutant IDH blocks liver progenitor cells from undergoing hepatocyte differentiation through the production of 2HG and suppression of HNF-4α, a master regulator of hepatocyte identity and quiescence. Correspondingly, genetically engineered mouse models expressing mutant IDH in the adult liver show an aberrant response to hepatic injury, characterized by HNF-4α silencing, impaired hepatocyte differentiation, and markedly elevated levels of cell proliferation. Moreover, IDH and Kras mutations, genetic alterations that co-exist in a subset of human IHCCs4, 5, cooperate to drive the expansion of liver progenitor cells, development of premalignant biliary lesions, and progression to metastatic IHCC. These studies provide a functional link between IDH mutations, hepatic cell fate, and IHCC pathogenesis, and present a novel genetically engineered mouse model of IDH-driven malignancy

Phase I Study of the Mutant IDH1 Inhibitor Ivosidenib: Safety and Clinical Activity in Patients With Advanced Chondrosarcoma

Surgery is the primary therapy for localized chondrosarcoma; for locally advanced and/or metastatic disease, no known effective systemic therapy exists. Mutations in the isocitrate dehydrogenase 1/2 (IDH1/2) enzymes occur in up to 65% of chondrosarcomas, resulting in accumulation of the oncometabolite D-2-hydroxyglutarate (2-HG). Ivosidenib (AG-120) is a selective inhibitor of mutant IDH1 approved in the United States for specific cases of acute myeloid leukemia. We report outcomes of patients with advanced chondrosarcoma in an ongoing study exploring ivosidenib treatment. This phase I multicenter open-label dose-escalation and expansion study of ivosidenib monotherapy enrolled patients with mutant advanced solid tumors, including chondrosarcoma. Ivosidenib was administered orally (100 mg twice daily to 1,200 mg once daily) in continuous 28-day cycles. Responses were assessed every other cycle using RECIST (version 1.1). Twenty-one patients (escalation, n = 12; expansion, n = 9) with advanced chondrosarcoma received ivosidenib (women, n = 8; median age, 55 years; range, 30-88 years; 11 had received prior systemic therapy). Treatment-emergent adverse events (AEs) were mostly grade 1 or 2. Twelve patients experienced grade ≥ 3 AEs; only one event was judged treatment related (hypophosphatemia, n = 1). Plasma 2-HG levels decreased substantially in all patients (range, 14%-94.2%), to levels seen in healthy individuals. Median progression-free survival (PFS) was 5.6 months (95% CI, 1.9 to 7.4 months); the PFS rate at 6 months was 39.5%. Eleven (52%) of 21 patients experienced stable disease. In patients with chondrosarcoma, ivosidenib showed minimal toxicity, substantial 2-HG reduction, and durable disease control. Future studies of ivosidenib monotherapy or rational combination approaches should be considered in patients with advanced mutant chondrosarcoma

Safety and activity of ivosidenib in patients with IDH1-mutant advanced cholangiocarcinoma: a phase 1 study

Isocitrate dehydrogenase-1 (IDH1) is mutated in up to 25% of cholangiocarcinomas, especially intrahepatic cholangiocarcinoma. Ivosidenib is an oral, targeted inhibitor of mutant IDH1 (mIDH1) approved in the USA for the treatment of mIDH1 acute myeloid leukaemia in newly diagnosed patients ineligible for intensive chemotherapy and patients with relapsed or refractory disease. Ivosidenib is under clinical evaluation in a phase 1 study that aims to assess its safety and tolerability in patients with mIDH1 solid tumours. Here we report data for the mIDH1-cholangiocarcinoma cohort. We did a phase 1 dose-escalation and expansion study of ivosidenib monotherapy in mIDH1 solid tumours at 12 clinical sites in the USA and one in France. The primary outcomes were safety, tolerability, maximum tolerated dose, and recommended phase 2 dose. Eligible patients had a documented mIDH1 tumour based on local testing, an Eastern Cooperative Oncology Group performance status of 0 or 1, one or more previous lines of therapy, and evaluable disease by Response Evaluation Criteria in Solid Tumors version 1.1. During dose escalation, ivosidenib was administered orally at 200-1200 mg daily in 28-day cycles in a standard 3 + 3 design; during expansion, patients received the selected dose on the basis of pharmacodynamic, pharmacokinetic, safety, and activity data from dose escalation. Safety and clinical activity analyses were reported for all patients with mIDH1-cholangiocarcinoma who were enrolled and received at least one dose of study treatment. Enrolment is complete, and the study is ongoing. This trial is registered at ClinicalTrials.gov, number NCT02073994. Between March 14, 2014 and May 12, 2017, 73 patients with mIDH1-cholangiocarcinoma were enrolled and received ivosidenib. No dose-limiting toxicities were reported and maximum tolerated dose was not reached; 500 mg daily was selected for expansion. Common (≥20%) adverse events, regardless of cause, were fatigue (31 [42%]; two [3%] grade ≥3), nausea (25 [34%]; one [1%] grade ≥3), diarrhoea (23 [32%]), abdominal pain (20 [27%]; two [3%] grade ≥3), decreased appetite (20 [27%]; one [1%] grade ≥3), and vomiting (17 [23%]). Common grade 3 or worse adverse events were ascites (four [5%]) and anaemia (three [4%]); the only treatment-related grade 3 or worse adverse event in more than one patient was fatigue (two [3%]). Two (3%) patients had serious adverse events leading to on-treatment death (Clostridioides difficile infection and procedural haemorrhage); neither was assessed by the investigator as related to treatment. 46 (63%) patients had adverse events deemed related to ivosidenib, of which four (5%) were grade 3 or higher (two [3%] for fatigue; one [1%] each for decreased blood phosphorus and increased blood alkaline phosphatase). One serious adverse event was considered possibly related to treatment (grade 2 supraventricular extrasystoles). Four (5%; 95% CI 1·5-13·4) patients had a partial response. Median progression-free survival was 3·8 months (95% CI 3·6-7·3), 6-month progression-free survival was 40·1% (28·4-51·6), and 12-month progression-free survival was 21·8% (12·3-33·0). Median overall survival was 13·8 months (95% CI 11·1-29·3); however, data were censored for 48 patients (66%). Ivosidenib might offer a well tolerated option for patients with mIDH1-cholangiocarcinoma. An ongoing, global phase 3 study is evaluating ivosidenib versus placebo in patients with previously treated nonresectable or metastatic mIDH1-cholangiocarcinoma. Agios Pharmaceuticals, Inc

Mutant IDH inhibits HNF-4α to block hepatocyte differentiation and promote biliary cancer

Mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 are among the most common genetic alterations in intrahepatic cholangiocarcinoma (IHCC), a deadly liver cancer1, 2, 3, 4, 5. Mutant IDH proteins in IHCC and other malignancies acquire an abnormal enzymatic activity allowing them to convert α-ketoglutarate (αKG) to 2-hydroxyglutarate (2HG), which inhibits the activity of multiple αKG-dependent dioxygenases, and results in alterations in cell differentiation, survival, and extracellular matrix maturation6, 7, 8, 9, 10. However, the molecular pathways by which IDH mutations lead to tumour formation remain unclear. Here we show that mutant IDH blocks liver progenitor cells from undergoing hepatocyte differentiation through the production of 2HG and suppression of HNF-4α, a master regulator of hepatocyte identity and quiescence. Correspondingly, genetically engineered mouse models expressing mutant IDH in the adult liver show an aberrant response to hepatic injury, characterized by HNF-4α silencing, impaired hepatocyte differentiation, and markedly elevated levels of cell proliferation. Moreover, IDH and Kras mutations, genetic alterations that co-exist in a subset of human IHCCs4, 5, cooperate to drive the expansion of liver progenitor cells, development of premalignant biliary lesions, and progression to metastatic IHCC. These studies provide a functional link between IDH mutations, hepatic cell fate, and IHCC pathogenesis, and present a novel genetically engineered mouse model of IDH-driven malignancy

Ivosidenib in IDH1-mutant, chemotherapy-refractory cholangiocarcinoma (ClarIDHy): a multicentre, randomised, double-blind, placebo-controlled, phase 3 study

BackgroundIsocitrate dehydrogenase 1 (IDH1) mutations occur in approximately 13% of patients with intrahepatic cholangiocarcinoma, a relatively uncommon cancer with a poor clinical outcome. The aim of this international phase 3 study was to assess the efficacy and safety of ivosidenib (AG-120)-a small-molecule targeted inhibitor of mutated IDH1-in patients with previously treated IDH1-mutant cholangiocarcinoma.MethodsThis multicentre, randomised, double-blind, placebo-controlled, phase 3 study included patients from 49 hospitals in six countries aged at least 18 years with histologically confirmed, advanced, IDH1-mutant cholangiocarcinoma who had progressed on previous therapy, and had up to two previous treatment regimens for advanced disease, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and a measurable lesion as defined by Response Evaluation Criteria in Solid Tumors version 1.1. Patients were randomly assigned (2:1) with a block size of 6 and stratified by number of previous systemic treatment regimens for advanced disease to oral ivosidenib 500 mg or matched placebo once daily in continuous 28-day cycles, by means of an interactive web-based response system. Placebo to ivosidenib crossover was permitted on radiological progression per investigator assessment. The primary endpoint was progression-free survival by independent central review. The intention-to-treat population was used for the primary efficacy analyses. Safety was assessed in all patients who had received at least one dose of ivosidenib or placebo. Enrolment is complete; this study is registered with ClinicalTrials.gov, NCT02989857.FindingsBetween Feb 20, 2017, and Jan 31, 2019, 230 patients were assessed for eligibility, and as of the Jan 31, 2019 data cutoff date, 185 patients were randomly assigned to ivosidenib (n=124) or placebo (n=61). Median follow-up for progression-free survival was 6·9 months (IQR 2·8-10·9). Progression-free survival was significantly improved with ivosidenib compared with placebo (median 2·7 months [95% CI 1·6-4·2] vs 1·4 months [1·4-1·6]; hazard ratio 0·37; 95% CI 0·25-0·54; one-sided p&lt;0·0001). The most common grade 3 or worse adverse event in both treatment groups was ascites (four [7%] of 59 patients receiving placebo and nine [7%] of 121 patients receiving ivosidenib). Serious adverse events were reported in 36 (30%) of 121 patients receiving ivosidenib and 13 (22%) of 59 patients receiving placebo. There were no treatment-related deaths.InterpretationProgression-free survival was significantly improved with ivosidenib compared with placebo, and ivosidenib was well tolerated. This study shows the clinical benefit of targeting IDH1 mutations in advanced, IDH1-mutant cholangiocarcinoma.FundingAgios Pharmaceuticals