Abstract 2569
Background
MEK inhibition may overcome resistance to EGFR inhibition alone in patients (pts) with RAS wt mCRC. We evaluated the antitumor activity of T (MEK1/2 inhibitor) with Pmab (EGFR monoclonal antibody) in a phase II trial.
Methods
Pts with KRAS, NRAS, and BRAF wt mCRC with prior 5-FU, irinotecan, oxaliplatin, +/- bevacizumab and no prior EGFR therapy were treated with T 1.5mg oral daily and Pmab 4.8mg/kg IV every 2 weeks. Primary endpoint was clinical benefit (CB; CR, PR or SD ≥ 24 weeks) by RECIST v1.1. A 2-stage minimax design (p0=0.20, p1=0.45, 1-sided alpha=0.05, power=0.85) required ≥4/13 patients with CB in stage I and ≥8/26 patients with CB by end of stage II. Response assessments were performed every 4 cycles (C). Adverse events (AEs) were assessed by CTCAE v4.03. Tumor biopsies were performed before C1 and during C2. Plasma circulating free DNA (cfDNA) collected before C1, C2, C3 and every 2 subsequent C and were profiled using the Oncomine Lung cfDNA assay.
Results
There were 13 pts enrolled from Nov2015 to Dec2018. Of 12 evaluable patients, best response was confirmed PR (n = 3), unconfirmed PR (n = 5), and SD (n = 4) (unconfirmed ORR 67%). Two patients achieved CB ≥ 24 weeks (2/10; 20%) and two patients are still on trial with PR not yet evaluable for CB. The most common treatment-related AE (trAE) was acneiform rash (85%) including 31% with grade 3. Other trAEs were diarrhea (62%), mucositis (46%), maculopapular rash (54%), and vomiting (31%). Dose modifications and interruptions of T occurred in 69% of patients and 54% of patients receiving Pmab had dose modifications. Median PFS is 4.4 months (95% CI 2.9-7.1). Of 3 pts with serial cfDNA profiling results available, none had KRAS, NRAS, or BRAF mutations detectable before treatment, and 1 patient demonstrated polyclonal KRAS, NRAS, and BRAF mutations at C5 before radiographic progression at C9.
Conclusions
The addition of T to Pmab leads to a high rate of tumor shrinkage in RAS/RAF wt mCRC. Median PFS is similar to Pmab alone in the ASPECCT trial, which may be due to a high incidence of skin toxicity with the combination that leads to dose interruption and/or reduction. Additional results from cfDNA and tumor biopsies will be presented.
Clinical trial identification
NCT02399943.
Editorial acknowledgement
Legal entity responsible for the study
Philippe Bedard.
Funding
Conquer cancer foundation of ASCO career development (Dr P. Bedard), Canadian Cancer Research Society Institute innovation grant (Dr P. Bedard), and drug supply from GlaxoSmithKline and Novartis.
Disclosure
A.R.R. Albiruni: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Boehringer Ingelheim; Advisory / Consultancy, Research grant / Funding (institution): Lilly; Advisory / Consultancy, Research grant / Funding (institution): Merck; Research grant / Funding (institution): CASI Pharmaceuticals; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Deciphera; Research grant / Funding (institution): Karyopharm Therapeutics; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Genentech/ Roche; Research grant / Funding (institution): Boston Biomedical; Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): MedImmune; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): GlaxoSmithKline; Research grant / Funding (institution): Blueprint Medicines; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): Adaptimmune. A. Spreafico: Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy: Oncorus; Research grant / Funding (institution): Symphogen AstraZeneca / Medimmune; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): Surface Oncology; Research grant / Funding (institution): Northern Biologics; Research grant / Funding (institution): Janssen Oncology/ Johnson & Johnson. A.R. Hansen: Advisory / Consultancy, Research grant / Funding (institution): Genentech/ Roche; Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): GlaxoSmithKline; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy, Research grant / Funding (institution): Boston Biomedical; Advisory / Consultancy, Research grant / Funding (institution): Boehringer-Ingelheim; Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Medimmune. L.L. Siu: Advisory / Consultancy, Research grant / Funding (institution): Merck; Advisory / Consultancy, Research grant / Funding (institution): Pfizer; Advisory / Consultancy, Research grant / Funding (institution): Celgene; Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca/ MedImmune; Advisory / Consultancy: Morphosys; Advisory / Consultancy: Roche; Advisory / Consultancy: GeneSeeq; Advisory / Consultancy: Loxo; Advisory / Consultancy: Oncorus; Advisory / Consultancy: Symphogen; Advisory / Consultancy: Seattle Genetics; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): Boehringer Ingelheim; Research grant / Funding (institution): GlaxoSmithKline; Research grant / Funding (institution): Genentech/Roche; Research grant / Funding (institution): Karyopharm; Research grant / Funding (institution): Astellas; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): AbbVie. P. Bedard: Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): Sanofi; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Genentech/Roche; Research grant / Funding (institution): SERVIER; Research grant / Funding (institution): GlaxoSmithKline; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): SignalChem; Research grant / Funding (institution): PTC Therapeutics; Research grant / Funding (institution): Nektar; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Seattle Genetics; Research grant / Funding (institution): Mersana; Research grant / Funding (institution): Immunomedics; Research grant / Funding (institution): Lilly. All other authors have declared no conflicts of interest.
Resources from the same session
1109 - First Canadian Interim Analysis from the Phase IIIb CompLEEment-1 Ribociclib + Letrozole HR+ HER2- Advanced Breast Cancer Trial
Presenter: Cristiano Ferrario
Session: Poster Display session 2
Resources:
Abstract
4401 - Real-world effectiveness of first-line palbociclib + letrozole for metastatic breast cancer 4 years post approval in the US
Presenter: Jonathan Kish
Session: Poster Display session 2
Resources:
Abstract
5876 - Palbociclib-Fulvestrant (PALBO-FUL) and Everolimus -Exemestane (EVE-EXE) for Second line Hormonal Treatment (HT) of Metastatic Breast Cancer (MBC) with Lobular Histology: a Propensity Score Matched Analysis of a Multicenter ‘Real-World’ Patients (pts) Series.
Presenter: Armando Orlandi
Session: Poster Display session 2
Resources:
Abstract
3587 - Dose-escalation study of G1T48, an oral selective estrogen receptor degrader (SERD), in postmenopausal women with ER+/HER2- locally advanced or metastatic breast cancer (ABC)
Presenter: E Dees
Session: Poster Display session 2
Resources:
Abstract
5696 - Final results of the STEM trial: SFX-01 in the Treatment and Evaluation of ER+ Her2- Metastatic breast cancer (mBC)
Presenter: Sacha Howell
Session: Poster Display session 2
Resources:
Abstract
1475 - Alpelisib (ALP) + Fulvestrant (FUL) in Hormone-Receptor Positive (HR+), Human Epidermal Growth Factor Receptor-2–Negative (HER2–) Advanced Breast Cancer (ABC): Subgroup Analysis by Presence of Visceral Metastasis (VM) in the SOLAR-1 Trial
Presenter: Mario Campone
Session: Poster Display session 2
Resources:
Abstract
2549 - Phase 1 Dose Escalation Study of a Selective Androgen Receptor Modulator RAD140 in Estrogen Receptor Positive (ER+), HER2 Negative (HER2-) Breast Cancer (BC)
Presenter: Erika Hamilton
Session: Poster Display session 2
Resources:
Abstract
3787 - A Phase I study of XZP-3287, a novel oral CDK4/6 Inhibitor, administered on a continuous dosing schedule, in patients with advanced solid tumours
Presenter: Binghe Xu
Session: Poster Display session 2
Resources:
Abstract
4835 - Phase-I dose-escalation and expansion study of the PARP inhibitor, fluzoparib (SHR3162), in patients with advanced solid tumors
Presenter: Huiping Li
Session: Poster Display session 2
Resources:
Abstract
5083 - Phase 2 study of DHP107 (Liporaxel®, oral paclitaxel) in first-line, HER2 negative recurrent/metastatic breast cancer (OPTIMAL study, NCT03315364)
Presenter: Jin-Hee Ahn
Session: Poster Display session 2
Resources:
Abstract