Phase 2 study of neoadjuvant dabrafenib + trametinib (D+T) for resectable stage iiib/c BRAF-V600 mutation positive melanoma.

Authors

null

Robyn Saw

Melanoma Institute Australia and The University of Sydney, North Sydney, Australia

Robyn Saw , Alexander M. Menzies , Alexander Guminski , Omgo E Nieweg , Kerwin F. Shannon , Maria Gonzalez , Sydney Ch'ng , Richard Kefford , John F Thompson , Jonathan Stretch , Andrew J Spillane , Richard A Scolyer , Georgina V. Long

Organizations

Melanoma Institute Australia and The University of Sydney, North Sydney, Australia, Melanoma Institute Australia, Royal North Shore Hospital, The University of Sydney, North Sydney, Australia, Melanoma Institute Australia, Sydney, Australia, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands, Melanoma Institute Australi, North Sydney, Australia, Melanoma Institute Australia, North Sydney, Australia, Institute of Academic Surgery, Royal Prince Alfred Hospital, Camperdown, Australia, Crown Princess Mary Cancer Centre, Sydney, Australia, Melanoma Institute Australia, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia, Melanoma Institute Australia; Mater Hospital; Royal Prince Alfred Hospital; The University of Sydney, North Sydney, Australia, Royal Prince Alfred Hospital/Melanoma Institute Australia/University of Sydney, Sydney, Australia

Research Funding

Other

Background: Combination D+T improves the overall survival (OS) of patients (pts) with V600 BRAF-mutation positive advanced melanoma. D+T is currently being explored in an adjuvant study of pts with resected stage III melanoma (NCT01682083). We sought to explore neoadjuvant D+T for pts with bulky but resectable stage III melanoma (NCT01972347). Methods: In this phase 2 study, all pts received D (150 mg twice daily) + T (2 mg once daily) for 12 wks prior to complete resection of the pre-therapy tumour bed (RES), then 40 wks of further D+T. Eligible pts were ≥ 18 yrs, ECOG PS ≤ 1 with histologically confirmed resectable bulky stage IIIB/C BRAF V600E/K mutant melanoma. CT and PET scans were performed at baseline and 12 wks just prior to RES for RECIST and metabolic complete response (rCR and mCR respectively). CT monitoring was continued 12 wkly thereafter to 2 yrs then 6 mnthly to 3 yrs. Biopsies were taken at baseline and wk 1. The primary endpoints were the complete pathological response (pCR) and RECIST response rate (rRR) at wk 12. Secondary endpoints were surgical morbidity, mCR, relapse free survival (RFS), OS, toxicity and translational endpoints. Results: At data cut 4 Jan 2016, 19 had commenced D+T. 14 had reached RES (10 stage IIIC [2 in-transit only], 4 IIIB; 12 V600E, 1 V00K, 1 V600). At RES, 6/14 (43%) had pCR, 5/14 (36%) had rCR (rRR 93%), and 7/14 (50%) had mCR. All 6 pts with pCR had mCR, but 2 did not have rCR. No pt progressed during neoadjuvant treatment. 2/14 pts recurred in the resected field 12 and 36 wks after RES on D+T. These pts had the highest ctDNA at baseline. 8/14 (57%) had ≥ 1 surgical complication post RES; 8 had a wound infection requiring antibiotics, 5 had a seroma, 2 bled (1 wound evacuation). 11/14 had a post RES drain (median drain time 27d). 12/14 (86%) interrupted D+T in the first 12 wks for a median of 7d, 9 due to pyrexia ( ≥ 38.5oC). 1 pt ceased D+T at wk 28 due to renal failure. Conclusions: A high rate of pCR was observed with neoadjuvant D+T for resectable stage III melanoma. pCR correlated with mCR, but not rCR. Surgical complication rates were consistent with historic controls and stage of disease. The trial and translational research is ongoing, and ease of resection, RFS and OS data are being collected. Clinical trial information: NCT01972347

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Abstract Details

Meeting

2016 ASCO Annual Meeting

Session Type

Poster Session

Session Title

Melanoma/Skin Cancers

Track

Melanoma/Skin Cancers

Sub Track

Local-Regional Disease

Clinical Trial Registration Number

NCT01972347

Citation

J Clin Oncol 34, 2016 (suppl; abstr 9583)

DOI

10.1200/JCO.2016.34.15_suppl.9583

Abstract #

9583

Poster Bd #

188

Abstract Disclosures