Incorporation of triapine (T) to cisplatin chemoradiation (CRT) for locally advanced cervical and vaginal cancer: Results from NRG-GY006, a phase III randomized trial

Abstract

Background

Cisplatin-based chemoradiation (CRT) plus brachytherapy for locally advanced cervical cancer (LACC) is standard. Intrinsic overexpression of ribonucleotide reductase (RNR) may enhance DNA damage repair from CRT. We report on outcomes of adding RNR inhibitor, triapine (T), to CRT.

Methods

NRG-GY006 is an open-label randomized phase III trial. FIGO 2009 LACC (stages IB2, II, IIIB or IVA) without para-aortic nodal involvement or stages II-IV vaginal cancer were eligible. Random assignment to CRT or in combination with thrice-weekly T (CRT + T) occurred. Radiation consisted of either 3D conformal (3DCRT) or image-guided intensity modulated RT (IG-IMRT) followed by intracavitary brachytherapy. Primary endpoint was overall survival (OS). Progression-free survival (PFS) was secondary. Exploratory endpoints included complete metabolic response rate on post treatment PET/CT imaging and comparative toxicity and outcomes for 3DCRT vs. IG-IMRT.

Findings

Four-hundred-fifty patients were randomized including 448 eligible (224 in CRT and 224 in CRT + T). Median age was 47 (range 23–85). The majority had cervical cancer (93.3 %) with squamous histology (82 %). 52 % had FIGO stage II disease. Racial/ethnic distribution included non-Hispanic white (53.8 %), black (15.2 %) and Hispanic/Latina (22.5 %). At randomization, IG-IMRT was planned in 74.3 % and HDR brachytherapy in 98.2 %. No differences in Grade 3–5 toxicities were observed: CRT: 52 % and CRT + T: 49 %, with two G5 toxicities (cardiac arrest and acidosis) in the CRT + T arm. The median patient follow-up was 28 months (IQR 15–45). HR for death was 1.018 (95 % CI 0.634–1.635) while HR for progression was 1.021 (95 % CI 0.694–1.501).

Interpretation

Triapine added to CRT did not improve OS.