Abstract 1106P
Background
Metastatic neuroendocrine neoplasms (mNEN) require new treatment options. We investigated intralesional (IL) PV-10, an autolytic immunotherapy that may elicit a disease-specific functional adaptive immune response.
Methods
Phase 1 study evaluating safety, tolerability and impact on symptoms and biochemical markers resulting from IL PV-10 administered percutaneously to hepatic lesions in patients (pts) with progressive mNEN following standard therapy. Injected lesion(s) had to be 1.0 to 3.9 cm in longest diameter. Cohort 1 (n = 6): PV-10 IL single lesion per treatment cycle, Cohort 2 (n = 6): injections to multiple lesions per treatment cycle if suitable. Pts could receive further PV-10 ≥6 weeks after prior injection. The primary endpoint was safety. Secondary endpoints ORR assessed by contrast enhanced CT (RECIST 1.1) and [68Ga] Ga -DOTATATE PET, biochemical response (CgA) and patient-reported outcome (EORTC QLQ-C30 and GI.NET21).
Results
Twelve pts were enrolled, 50% male, median age 66 yrs (range 47-79). Primary sites: 7 small bowel, 2 pancreas, 1 caecal, 2 unknown; grade: Gd1 = 5, Gd2 = 7. All pts had received prior SSA and PRRT with progressive disease prior to enrolment. Median CgA was 1585 (range 35-10370). One lesion was injected per procedure for all 12 pts; none were suitable for multiple injections. Median dose per cycle (ml) was 1.9 (range 0.5-8.7). PV-10 treatment cycles; 4 n=1, 2 n=3, 1 n=8. Toxicity; Grade (gd) 1/2 transient post-procedure pain reported 9 pts, Photosensitivity rash gd 3 one patient; gd 1 elevation transaminases 2 pts, gd 3 in one, resolving by day 7. Gd 1/2 Carcinoid flare or increased flushing occurred in 6 pt. Gd 1/2 chromaturia was noted in 4 pts. ORR in injected lesions was 42%; overall disease control was 84%. CgA remained stable in 10 pts. Med PFS 9.2 months; OS 22.5 months. Estimated 3 yr PFS and OS is 27% & 49% respectively. HRQOL scores were stable or improved in 8 of 11 patients at mth1, and maintained at mth3 in 6 of 10 patients.
Conclusions
PV-10 elicited no safety concerns and multiple cycles were delivered safely in suitable patients. Encouraging evidence of local and systemic disease control with improvement in HRQoL was noted in a heavily pre-treated, progressing mNEN population.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Provectus.
Funding
Provectus.
Disclosure
E. Wachter: Financial Interests, Personal, Full or part-time Employment: Provectus. D. Rodrigues: Financial Interests, Personal, Full or part-time Employment: Provectus. G. Maddern: Financial Interests, Institutional, Research Grant: Provectus. All other authors have declared no conflicts of interest.