The safety and efficacy of PEN-221 somatostatin analog (SSA)-DM1 conjugate in patients (pts) with advanced GI mid-gut neuroendocrine tumor (NET): Phase 2 Results
Halperin, D. M. Johnson, M. L. Chan, J. A. Hart, L. L. Patel, V. M. Schlecter, B. L. Cave, J. Dowlati, A. Blaszkowsky, L. S.
Halperin, D. M.
Johnson, M. L.
Chan, J. A.
Hart, L. L.
Patel, V. M.
Schlecter, B. L.
Cave, J.
Dowlati, A.
Blaszkowsky, L. S.
Citations
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Abstract
BACKGROUND: PEN-221 is a small molecule drug conjugate composed of a
SSTR2 binding somatostatin analog linked to the toxin DM1. PEN-221-001 was
a study which assessed the safety, tolerability, pharmacokinetics (PK), and
preliminary efficacy of PEN-221 in well differentiated neuroendocrine tumors
(NETs) and small cell lung cancer.
METHODS: Pts with advanced, SSTR2+ GI mid-gut NETs were enrolled in this
cohort of study PEN-221-001. The primary objective was to determine the safety and efficacy of PEN-221 given intravenously, every (q) 3 weeks. Preliminary
efficacy was assessed using RECIST 1.1. A clinically meaningful efficacy result was
defined as a Clinical Benefit Rate (CBR) > 75% and a median progression-free
survival (mPFS) > 8 months.
RESULTS: 32 patients were enrolled between January 2018 to June 2020 and the
data cut-off for this report is July 31, 2020. The mean number of cycles received
was 7 (range 1-18), with 5 pts still on treatment at time of data lock. PEN-221
was well tolerated in all pts at the dose of 8.8 mg/m2. The most frequent (≥20%
pts) PEN-221 related adverse events were nausea (50%), fatigue (47%), diarrhea
(47%), decreased appetite (47%), peripheral neuropathy (34%), infusion reaction
(31%), AST/ Alk Phos/ALT increase (28/25/22%), and anemia (25%). Only 11 (34%)
of these events were ≥grade 3. Of the 26 pts who were evaluable for response,
23 (88.5%) had stable disease (SD) reported as their best response with a CBR of
88.5%. Target lesion shrinkage was observed in 10 (38%) patients. The mPFS for
this cohort was 9 months (CI 5 - 16.5 months). Tumor marker data will also be
presented.
CONCLUSION: PEN-221 appears well tolerated at 8.8 mg/m2 q 3 weeks and has
demonstrated efficacy exceeding its clinical efficacy goals with a CBR of 88.5%
and a mPFS of 9 months.
Description
Date
2022
Publisher
Collections
Keywords
Type
Meetings and Proceedings
Citation
Halperin DM, Johnson ML, Chan JA, Hart LL, Cook N, Patel VM, et al. The Safety and Efficacy of PEN-221 Somatostatin Analog (SSA)-DM1 Conjugate in Patients (Pts) With Advanced GI Mid-gut Neuroendocrine Tumor (NET): Phase 2 Results. Pancreas. 2022 Mar;51(3):E37-E. PubMed PMID: WOS:000819123700038.