P-162 - Interim Results of IMMU-132 (Sacituzumab Govitecan), an Anti-Trop-2 Antibody-Drug Conjugate (ADC), in Patients (pts) with Metastatic Gastrointestina...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Cancer Immunology and Immunotherapy
Gastrointestinal Cancers
Presenter A. Ocean
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors A. Ocean1, A. Starodub2, W. Messersmith3, V. Picozzi4, M. Guarino5, S. Thomas6, A. Bardia7, M. Shah1, S. Govindan1, P. Maliakal1, W. Wegener8, R. Sharkey1, F. Wilhelm1, D. Goldenberg1
  • 1New York/US
  • 2Goshen/US
  • 3Aurora/US
  • 4Seattle/US
  • 5Newark/US
  • 6Orlando/US
  • 7Boston/US
  • 8Morris Plains/US



IMMU-132 is a novel ADC comprising SN-38, the active metabolite of irinotecan, conjugated at a high drug:antibody ratio to the humanized anti-Trop-2 antibody, RS7, by a site-specific conjugation method. It shows potent activity in human tumor xenograft models expressing Trop-2, which is highly prevalent in many different solid cancers.


Pts with relapsed/refractory metastatic GI cancers were enrolled in this Phase II expansion trial (NCT01631552) after establishing the acceptable dosing schedule of 8-10 mg/kg on days 1 and 8 of a 21-day cycle, repeated as long as efficacy and safety permitted.


68 pts were enrolled. Neutropenia was the main dose-limiting toxicity, with alopecia, fatigue, diarrhea, nausea, and vomiting as other reported toxicities, but mostly grades 1/2, except for neutropenia (29% grades 3/4). Number of prior therapies and of IMMU-132 3-week cycles per tumor type are reported below. Of 29 CRC pts, 1 pt had a PR and 14 pts had SD as best response by RECIST1.1, with PFS of 3.9 months and OS of 18 months. Thirteen colorectal cancer pts had RAS mutations. Of 15 pts with pancreatic cancer, 8 pts had SD as best response, with PFS of 1.9 months and OS of 4.5 months. Among 17 assessable pts with esophageal cancer, there were 2 pts with PRs and 8 pts with SD as best responses with median PFS of 4.1 months (OS not yet reached). Of 5 gastric cancer pts, 3 pts had SD. No pt showed an anti-antibody or anti-SN-38 response, despite repeated injections for several months in many pts.


IMMU-132 appears to have a manageable safety profile with less frequent and severe diarrhea than irinotecan. Encouraging activity has been observed in certain advanced GI cancers, which indicates the potential of this ADC being included in combination therapies.

Table: P-162