Dataset Information

A phase 2 study of the PARP inhibitor veliparib plus temozolomide in patients with heavily pretreated metastatic colorectal cancer.

ABSTRACT:

Background

Poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors such as veliparib are potent sensitizing agents and have been safely combined with DNA-damaging agents such as temozolomide. The sensitizing effects of PARP inhibitors are magnified when cells harbor DNA repair defects.

Methods

A single-arm, open-label, phase 2 study was performed to investigate the disease control rate (DCR) after 2 cycles of veliparib plus temozolomide in patients with metastatic colorectal cancer (mCRC) refractory to all standard therapies. Fifty patients received temozolomide (150 mg/m² /d) on days 1 to 5 and veliparib (40 mg twice daily) on days 1 to 7 of each 28-day cycle. Another 5 patients with mismatch repair-deficient (dMMR) tumors were also enrolled. Twenty additional patients were then treated with temozolomide at 200 mg/m² /d. Archived tumor specimens were used for immunohistochemistry to assess mismatch repair, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and O(6)-methylguanine-DNA methyltransferase (MGMT) protein expression levels.

Results

The combination was well tolerated, although some patients required dose reductions for myelosuppression. The primary endpoint was successfully met with a DCR of 24% and 2 confirmed partial responses. The median progression-free survival was 1.8 months, and the median overall survival was 6.6 months. PTEN protein expression and MGMT protein expression were not predictors of DCR. There was also a suggestion of worse outcomes for patients with dMMR tumors.

Conclusions

In this heavily pretreated mCRC population, a combination of veliparib and temozolomide was well tolerated with temozolomide doses up to 200 mg/m² /d, and it was clinically active. PARP inhibitor-based therapy merits further exploration in patients with mCRC. Cancer 2018;124:2337-46. © 2018 American Cancer Society.

SUBMITTER: Pishvaian MJ

PROVIDER: S-EPMC5992024 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Publications

A phase 2 study of the PARP inhibitor veliparib plus temozolomide in patients with heavily pretreated metastatic colorectal cancer.

Pishvaian Michael J MJ Slack Rebecca S RS Jiang Wei W He A Ruth AR Hwang Jimmy J JJ Hankin Amy A Dorsch-Vogel Karen K Kukadiya Divyesh D Weiner Louis M LM Marshall John L JL Brody Jonathan R JR

Cancer 20180326 11

<h4>Background</h4>Poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors such as veliparib are potent sensitizing agents and have been safely combined with DNA-damaging agents such as temozolomide. The sensitizing effects of PARP inhibitors are magnified when cells harbor DNA repair defects.<h4>Methods</h4>A single-arm, open-label, phase 2 study was performed to investigate the disease control rate (DCR) after 2 cycles of veliparib plus temozolomide in patients with metastatic colorect ...[more]

PMID: 29579325

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Project description:ImportanceRechallenge therapy with anti-epidermal growth factor receptor (EGFR) drugs has been suggested in patients with chemo-refractory RAS wild-type (WT) metastatic colorectal cancer (mCRC) after initial response to anti-EGFR-based first-line treatment. The association of treatment with cetuximab plus avelumab with overall survival (OS) may be worthy of investigation in this setting.ObjectiveTo assess the efficacy and safety of cetuximab rechallenge therapy plus avelumab.Design, setting, and participantsThis single-arm, multicenter phase 2 trial enrolled patients from August 2018 to February 2020. Eligible patients with RAS WT mCRC had a complete or partial response to first-line chemotherapy plus anti-EGFR drugs, developed acquired resistance, and failed second-line therapy. Baseline circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R mutation analysis was done.InterventionsPatients received avelumab (10 mg/kg every 2 weeks) and cetuximab (400 mg/m2 and, subsequently, 250 mg/m2 weekly) until disease progression or unacceptable toxic effects.Main outcomes and measuresThe primary end point was OS. Secondary end points were progression-free survival (PFS), overall response rate (ORR), and safety.ResultsSeventy-seven patients were enrolled (42 men, 35 women; median age, 63 years); 71 had microsatellite stable tumors (MSS), 3 microsatellite instability-high tumors (MSI-H), 3 unknown. The study met the primary end point, with median OS (mOS) of 11.6 months (95% CI, 8.4-14.8 months). Median PFS (mPFS) was 3.6 months (95% CI, 3.2-4.1 months). Common grade-3 adverse events were cutaneous eruption, 11 (14%), and diarrhea, 3 (4%). For 67 of 77 (87%) patients, baseline analysis of plasma circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R variations was feasible. Forty-eight patients had WT disease, whereas 19 had mutations. Patients with RAS/BRAF WT ctDNA had mOS of 17.3 months (95% CI, 12.5-22.0 months) compared with 10.4 months (95% CI, 7.2-13.6 months) in patients with mutated ctDNA (hazard ratio [HR], 0.49; 95% CI, 0.27-0.90; P = .02). The mPFS was 4.1 months (95% CI, 2.9-5.2 months) in RAS/BRAF WT patients compared with 3.0 months (95% CI, 2.6-3.5 months) in patients with mutated ctDNA (HR, 0.42; 95% CI, 0.23-0.75; P = .004).Conclusions and relevanceThe findings of this single-arm phase 2 trial suggest that cetuximab plus avelumab is an active, well tolerated rechallenge therapy in RAS WT mCRC. Plasma ctDNA analysis before treatment may allow selection of patients who could benefit.Trial registrationClinicalTrials.gov Identifier: NCT04561336.

Dataset Information

A phase 2 study of the PARP inhibitor veliparib plus temozolomide in patients with heavily pretreated metastatic colorectal cancer.

Background

Methods

Results

Conclusions

Publications

A phase 2 study of the PARP inhibitor veliparib plus temozolomide in patients with heavily pretreated metastatic colorectal cancer.

Similar Datasets

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