2019年8月26日に英国マンチェスターで開催されるInternational Congress of Radiation Research（ICRR）2019において、英国The Royal Marsden Hospitalで実施された局所進行性乳がんに対する放射線増感剤KORTUCの治験（第Ⅰ相）の結果が報告される予定です。治験責任医師であるInstitute of Cancer ResearchのDr Navita Somaiahが口頭発表します。
KORTUC phase I trial testing hydrogen peroxide as a novel radiation sensitiser in patients with locally advanced/recurrent breast cancer
Preclinical studies and non-randomised clinical trials in Japan have suggested a radiosensitising effect of intratumoural 0.5% hydrogen peroxide in 1% sodium hyaluronate gel (KORTUC). Local control rates of 79-100% at up to 5 years follow-up were reported. A UK Phase I trial was undertaken to confirm safety of KORTUC during external beam radiotherapy (RT) in patients with breast cancer with/without metastases.
Patients with breast tumours ≥3cm requiring RT for local control were recruited and assigned 36Gy/6# twice-weekly or 49.5Gy/18# daily, according to performance status. Twice-weekly intratumoural KORTUC injections were administered (1h before RT) under ultrasound guidance, commencing in the 2nd week of RT. The primary endpoint was maximum intratumoural pain intensity. Secondary endpoints included ≥ grade 3 skin toxicity lasting >6 weeks after RT, and tumour response at 3 months. Blood samples were collected at baseline, post-RT alone and post-RT+KORTUC.
13 patients (11♀, 2♂) consented; 1 withdrew prior to treatment due to clinical deterioration. Mean age was 70 years (range 45-93). All patients completed the trial protocol (equally divided between the regimens). Following injection, 10/12 and 2/12 patients experienced grade 1 and 2 local tumour pain respectively. Median pain duration was 10min (IQR 0-60min). Skin toxicity was G0-2 in 7 patients, and G3 in 5 patients (treated with bolus). Ultrasound assessment at 3 months demonstrated partial response in 5/11 (45%) and stable disease in 6/11 (55%), with no loco-regional progression at last follow-up (7/12 completed 12 months). One patient died of metastatic disease prior to the 3-month timepoint. Blood sample analysis is underway (apoptosis/necroptosis/immunogenic markers).
KORTUC in combination with RT is safe and well tolerated, with comparable toxicity to standard RT alone. Pain following injection was short-lived and manageable with simple analgesia. A UK multicentre randomised Phase II trial (RT +/- KORTUC) is planned this year.