Patient characteristics after completion of recruitment from the phase 3 IMPALA study with lefitolimod in metastatic colorectal carcinoma

Abstract

Background: The TLR9 agonist lefitolimod is a covalently‐closed dumbbell‐like immune surveillance reactivator with a broad immunomodulatory potential. After promising data from the phase 2 IMPACT trial as maintenance therapy after 1st line induction chemotherapy in patients with metastatic colorectal cancer (mCRC) lefitolimod is now evaluated in the phase 3 IMPALA trial in mCRC patients. Trial Design: The international, multicenter, randomized, open‐label phase 3 IMPALA trial is conducted in collaboration with the AIO, TTD and GERCOR cooperative groups (NCT02077868). IMPALA's primary endpoint is OS; secondary endpoints include PFS, response rates, and safety. Induction treatment, CEA and activated NKT are stratification factors for prospective assessment. Patients having achieved an objective tumor response following 1st line induction therapy receive lefitolimod switch maintenancemonotherapy or local standard of care (control). In case of relapse, patients will reintroduce induction treatment, whenever feasible, with those in the experimental arm continuing to receive lefitolimod therapy in the weeks without infusion of chemotherapy. Recruitment took 32 months from Sep 2014 untilMay 2017 to include 549 of 630 patients screened; with unresectable mCRC and 'fit for chemotherapy'. Sites from 8 European countries participated and accrued 274 patients in the lefitolimod and 275 in the control arm (Austria, 6 patients; Belgium, 8; Estonia, 34; France, 87; Germany, 191; Italy, 54; Spain, 132; UK, 37). 116 female (42.3%) and 158male (57.7%) were included into the lefitolimod and 92 female (33.5%) and 183male (66.5%) into the control arm. The median age is 65 years both in the lefitolimod and the control arm. Age group distribution showed also a similar pattern: 12 vs 7 patients from 24‐43 yo, 112 vs 114 from 44‐63 yo, 56 vs 55 from 64‐68 yo, 37 vs 46 from 69‐73 yo, 35 vs 37 from 74‐78 yo, 19 vs 15 from 79‐83 yo and 3 vs 1 from 84‐88 yo in the lefitolimod vs the control arm as pre‐requisite to guide maintenance therapy in the future.