A phase II study of guadecitabine combined with irinotecan vs regorafenib or TAS-102 in irinotecan-refractory metastatic colorectal cancer patients

DNA methyltransferase inhibitors (DNMTi) have demonstrated benefit in reversing resistance to systemic therapies for several cancer types. In a phase II trial of guadecitabine and irinotecan compared to regorafenib or TAS-102 in pts with advanced mCRC refractory to irinotecan. Patients with mCRC refractory to irinotecan were randomized 2:1 to guadecitabine and irinotecan (Arm A) vs standard of care regorafenib or TAS-102 (Arm B) on a 28-day cycle. Between January 15, 2016 and October 24, 2018, 104 pts were randomized at four international sites, with 96 pts undergoing treatment, 62 in Arm A and 34 in Arm B. Median overall survival was 7.15 months for Arm A and 7.66 months for Arm B (HR 0.93, 95% CI: 0.58-1.47, P = .75). The Kaplan-Meier rates of progression free survival at 4 months were 32% in Arm A and 26% in Arm B. Common ≥Grade 3 treatment related adverse events in Arm A were neutropenia (42%), anemia (18%), diarrhea (11%), compared to Arm B pts with neutropenia (12%), anemia (12%). Guadecitabine and irinotecan had similar OS compared to standard of care TAS-102 or regorafenib, with evidence of target modulation. Clinical trial information: NCT01896856.

A phase 2 trial of gemcitabine and docetaxel in patients with metastatic colorectal adenocarcinoma with methylated checkpoint with forkhead and ring finger domain promoter and/or microsatellite instability phenotype

Abstract

We previously reported CHFR methylation in a subset of colorectal cancer (CRC; ∼30%) with high concordance with microsatellite instability (MSI). We also showed that CHFR methylation predicted for sensitivity to docetaxel, whereas the MSI‐high phenotypes were sensitive to gemcitabine. We hypothesized that this subset of patients with CRC would be selectively sensitive to gemcitabine and docetaxel. We enrolled a Phase 2 trial of gemcitabine and docetaxel in patients with MSI‐high and/or CHFR methylated CRC. The primary objective was Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 response rate. Enrolled patients were treated with gemcitabine 800 mg/m² on days 1 and 8 and docetaxel 70 mg/m² on day 8 of each 21‐day cycle. A total of 6 patients with CHFR‐methylated, MSI‐high CRC were enrolled from September 2012 to August 2016. The study was closed in September of 2017 due to poor accrual prior to reaching the first interim assessment of response rate, which would have occurred at 10 patients. No RECIST criteria tumor responses were observed, with 3 patients (50%) having stable disease as best response, 1 lasting more than 9 months. Median progression‐free survival (PFS) was 1.79 months (95% confidence interval [CI] = 1.28, not available [NA]) and median overall survival (OS) was 15.67 months (95% CI = 4.24, NA). Common grade 3 toxicities were lymphopenia (67%), leukopenia (33%), and anemia (33%). Although negative, this study establishes a proof‐of‐concept for the implementation of epigenetic biomarkers (CHFR methylation/MSI) as inclusion criteria in a prospective clinical trial to optimize combinatorial strategies in the era of personalized medicine.

A Phase I Trial of a Guadecitabine (SGI-110) and Irinotecan in Metastatic Colorectal Cancer Patients Previously Exposed to Irinotecan

PURPOSE

Chemotherapeutic resistance eventually develops in all patients with metastatic colorectal cancer (mCRC). Gene silencing through promoter demethylation is one potential reversible mechanism of resistance with administration of hypomethylating agents. We evaluated the safety and tolerability of guadecitabine and irinotecan in patients with mCRC previously treated with irinotecan.

PATIENTS AND METHODS

In this 3+3 dose-escalation study, patients with mCRC previously exposed to irinotecan received guadecitabine days 1 to 5 of a 28-day cycle and irinotecan 125 mg/m2 days 8 and 15 [dose level (DL) 1, guadecitabine 45 mg/m2; DL -1: guadecitabine 30 mg/m2; DL -1G: guadecitabine 30 mg/m2 with growth factor support (GFS); DL 1G: guadecitabine 45 mg/m2 with GFS].

RESULTS

Twenty-two patients were treated across four DLs. Dose-limiting toxicities were neutropenic fever (DL 1 and -1G), biliary drain infection (DL -1), colonic obstruction (DL -1), and severe dehydration (DL 1G). Most common toxicities were neutropenia (82% any grade, 77% Grade 3/4), neutropenic fever (23%), leukopenia (73% any grade, 50% Grade 3/4), and injection site reactions (64% total, 0% Grade 3/4). Patients received a median of 4.5 cycles of treatment; 12/17 evaluable patients had stable disease as best response, with one having initial disease progression but subsequently durable partial response. Circulating tumor DNA showed decrease in global demethylation by LINE-1 after treatment.

CONCLUSIONS

We report the first study of chemo-priming with epigenetic therapy in gastrointestinal cancers. Guadecitabine 45 mg/m2 and irinotecan 125 mg/m2 with GFS was safe and tolerable in patients with mCRC, with early indication of benefit. These data have provided the basis for an ongoing phase II randomized, multicenter trial.

Abstract CT017: A phase I study of guadecitabine (GUA) combined with irinotecan (IRI) in previously treated metastatic colorectal cancer (mCRC) patients

Background: Treatment of IRI-resistant CRC lines with a DNA methyltransferase inhibitor (DNMTi) can induce IRI re-sensitization. We theorized that combination of next generation DNMTi GUA+IRI would overcome resistance in previously IRI-treated mCRC pts.

Methods: mCRC pts with prior IRI exposure were enrolled in a 3+3 Phase I, dose escalation study to define the maximum tolerated dose (MTD) and dose limiting toxicities of GUA+IRI. Pharmacodynamics studies were planned on pre- and post-treatment tumor biopsies (C1D8); serial blood was also taken. Pts were enrolled to 4 dose levels (DL) of GUA SQ qd D1-5 with IRI 125mg/m2 D8 and 15: GUA 45mg/m2 (DL 1), 30mg/m2 (DL -1), 30mg/m2 with growth factor support (GFS) (DL -1G), and 45mg/m2 with GFS (DL 1G) of a 28 day cycle.

Results: 22 heavily pre-treated pts were enrolled (DL 1 = 6, DL -1 = 3, DL -1G = 7, DL 1G = 6); the MTD was established at DL 1G. Grade (G) 3-5 toxicities attributed to therapy were hematologic [neutropenia (16), neutropenic fever (5), anemia (3), thrombocytopenia (2)]. Other G3-4 toxicities were diarrhea (3), fatigue (2), and dehydration (2). There was one death on study possibly due to study treatment (febrile neutropenia). There were some dose reductions of IRI (6) or GUA (3). Median cycles of therapy were 4 months (range 1-14). 15 pts had at least one restaging scan, 12:SD and 1:PR. LINE-1 methylation analysis on serial biopsies revealed mixed changes in global methylation on C1D8, but LINE-1 of circulating tumor DNA showed consistent, delayed, dose-dependent demethylation with peak demethylation at C2D15.

Conclusions: GUA+IRI is well tolerated and demonstrates potentially compelling activity in mCRC pts with prior IRI exposure. Further testing of the combination is ongoing in a randomized phase II trial (2:1 randomization to GUA+IRI or TAS-102/Regorafenib - provider choice). Clinical trial information: NCT01896856. Supported by Astex Pharma and VARI SU2C/AACR Epigenetics Dream Team. Toxicity attributable to therapy in ≤ 10% of patientsAny GG1/G2G3/G4/G5N (%)N (%)N (%)HematologicNeutropenia16 (73)0 (0)16 (73)Anemia13 (59)10 (45)3 (14)Thrombocytopenia9 (41)7 (32)2 (9)InfectionNon-neutropenic infection6 (27)6 (27)0 (0)Febrile Neutropenia5 (23)0 (0)5 (23) 1 death DL-1GFever9 (41)8 (36)1 (5)GastrointestinalNausea/Vomiting16 (73)16 (73)0 (0)Abdominal discomfort4 (18)4 (18)0 (0)Diarrhea11 (50)8 (36)3 (14)Constipation4 (18)4 (18)0 (0)Increased AST4 (18)3 (14)1 (5)Increased alkaline phosphatase9 (41)8 (36)1 (5)Injection Site Reactions15 (68)15 (68)0 (0)GeneralFatigue10 (45)8 (36)2 (9)Anorexia/Weight loss9 (41)8 (36)1 (5)Alopecia7 (32)7 (32)0 (0)Lower extremity edema5 (23)5 (23)0 (0)Dehydration5 (23)3 (14)2 (9)Headache3 (14)3 (14)0 (0)Taste changes4 (18)4 (18)0 (0)

Citation Format: Valerie Lee, Judy Wang, Anthony El Khoueiry, Henk Verheul, Elske Gootjes, Anup Sharma, Zachary Kerner, Peter Jones, Stephen Baylin, Ellen Lilly, Nita Ahuja, Thomas Brown, Nilofer Azad. A phase I study of guadecitabine (GUA) combined with irinotecan (IRI) in previously treated metastatic colorectal cancer (mCRC) patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT017.