Paulson, Andrew Scott

LBA661 Background: Liposomal irinotecan administered with 5-fluorouracil/leucovorin (5-FU/LV) is approved in the USA and Europe for mPDAC following progression with gemcitabine-based therapy. A phase 1/2 study (Wainberg et al. Eur J Cancer 2021;151:14–24; NCT02551991) demonstrated promising anti-tumor activity in patients with mPDAC who received first-line liposomal irinotecan 50 mg/m2 + 5-FU 2400 mg/m2 + LV 400 mg/m2 + oxaliplatin 60 mg/m2 (NALIRIFOX). Herein, we present results from NAPOLI-3 (NCT04083235), a randomized, open-label, phase 3 study investigating the efficacy and safety of NALIRIFOX compared with nab-paclitaxel + gemcitabine as first-line therapy in patients with mPDAC. Methods: Eligible patients with histopathologically/cytologically confirmed untreated metastatic PDAC were randomized (1:1) to receive NALIRIFOX on days 1 and 15 of a 28-day cycle or nab-paclitaxel 125 mg/m2 + gemcitabine 1000 mg/m2 (Gem+NabP) on days 1, 8 and 15 of a 28-day cycle. Randomization was stratified by ECOG performance status, geographic region and presence or absence of liver metastases. The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), overall response rate (ORR) and safety. OS was evaluated when ≥ 543 events were observed using a stratified log-rank test with an overall 1-sided significance level of 0.025. Results: Overall, 770 patients (NALIRIFOX, n = 383; Gem+NabP, n = 387) were included. Baseline characteristics were well balanced between arms. At a median follow-up of 16.1 months, 544 events had occurred. The median OS was 11.1 months in the NALIFIROX arm as compared with 9.2 months in the Gem+NabP arm (HR 0.84 [95% CI 0.71–0.99]; p = 0.04); PFS was also significantly improved (7.4 months vs 5.6 months; HR 0.70 [0.59–0.84]; p = 0.0001). Grade 3/4 treatment-emergent adverse events (TEAEs) with ≥ 10% frequency in patients receiving NALIRIFOX versus Gem+NabP included diarrhea (20.3% vs 4.5%), nausea (11.9% vs 2.6%), hypokalemia (15.1% vs 4.0%), anemia (10.5% vs 17.4%) and neutropenia (14.1% vs 24.5%). Conclusions: First-line NALIRIFOX demonstrated clinically meaningful and statistically significant improvement in OS and PFS compared with Gem+NabP in treatment-naïve patients with mPDAC. The safety profile of NALIRIFOX was manageable and consistent with the profiles of the treatment components. Funding: Funded by Ipsen. Clinical trial information: NCT04083235 .[Table: see text]

198 Background: HER2 overexpression/amplification (HER2+) occurs in 3%-5% of patients (pts) w/ metastatic colorectal cancer (mCRC). Rates of HER2+ can increase to ~10% in pts w/ RAS/BRAF wild-type mCRC tumors. The MOUNTAINEER trial (NCT03043313) evaluated the efficacy and safety of the investigational combination of tucatinib with trastuzumab in pts with HER2+ and RAS wild-type mCRC. Established regional guidelines for mCRC recommend HER2 testing and HER2-directed treatment options; however, there is currently no established best practice for HER2 testing and interpretation in mCRC. Here, we present data from a concordance analysis comparing breast and gastric HER2 testing algorithms in the mCRC setting. Methods: The MOUNTAINEER trial enrolled pts w/ HER2+ mCRC identified using ≥1 method: tissue-based local immunohistochemistry (IHC), in situ hybridization (ISH), and/or next-generation sequencing (NGS) testing. Archival or fresh tumor tissue was submitted to a sponsor-designated central laboratory for confirmatory HER2 testing w/ IHC/FISH per the package insert of the FDA approved assay and scored by both the breast and gastric algorithms for HER2 IHC. A positive result per the breast scoring criteria for IHC requires circumferential membrane staining for HER2, while the gastric criteria allows for circumferential, basolateral, or lateral staining patterns. Results: A total of 114 pts were enrolled with HER2+ tumors per ≥1 local testing methods; 69 pts were HER2+ by NGS, 46 by IHC 3+, and 36 by ISH. Of 105 pts who had tissue available for central HER2 testing w/IHC/FISH, 98 had valid HER2 results; 82/98 (83.7%) of pts had tumors centrally confirmed as HER2+ using both the breast and gastric algorithms. Tissue samples from pts in the MOUNTAINEER trial had 100% concordance between breast and gastric algorithms in HER2 status and 99% concordance in HER2 IHC score. Conclusions: Central pathology testing using both the breast and gastric criteria showed high concordance between these two commonly used algorithms. A high central confirmation rate of local HER2+ results was also observed. These data support the use of either the breast or gastric algorithms to identify HER2+ mCRC tumors until an FDA-approved HER2 assay is available for mCRC. Clinical trial information: NCT03043313 . [Table: see text]

PURPOSE This randomized, open-label trial compared the efficacy and safety of adjuvant nab-paclitaxel + gemcitabine with those of gemcitabine for resected pancreatic ductal adenocarcinoma (ClinicalTrials.gov identifier: NCT01964430 ). METHODS We assigned 866 treatment-naive patients with pancreatic ductal adenocarcinoma to nab-paclitaxel (125 mg/m 2 ) + gemcitabine (1,000 mg/m 2 ) or gemcitabine alone to one 30-40 infusion on days 1, 8, and 15 of six 28-day cycles. The primary end point was independently assessed disease-free survival (DFS). Additional end points included investigator-assessed DFS, overall survival (OS), and safety. RESULTS Two hundred eighty-seven of 432 patients and 310 of 434 patients completed nab-paclitaxel + gemcitabine and gemcitabine treatment, respectively. At primary data cutoff (December 31, 2018; median follow-up, 38.5 [interquartile range [IQR], 33.8-43 months), the median independently assessed DFS was 19.4 ( nab-paclitaxel + gemcitabine) versus 18.8 months (gemcitabine; hazard ratio [HR], 0.88; 95% CI, 0.729 to 1.063; P = .18). The median investigator-assessed DFS was 16.6 (IQR, 8.4-47.0) and 13.7 (IQR, 8.3-44.1) months, respectively (HR, 0.82; 95% CI, 0.694 to 0.965; P = .02). The median OS (427 events; 68% mature) was 40.5 (IQR, 20.7 to not reached) and 36.2 (IQR, 17.7-53.3) months, respectively (HR, 0.82; 95% CI, 0.680 to 0.996; P = .045). At a 16-month follow-up (cutoff, April 3, 2020; median follow-up, 51.4 months [IQR, 47.0-57.0]), the median OS (511 events; 81% mature) was 41.8 ( nab-paclitaxel + gemcitabine) versus 37.7 months (gemcitabine; HR, 0.82; 95% CI, 0.687 to 0.973; P = .0232). At the 5-year follow-up (cutoff, April 9, 2021; median follow-up, 63.2 months [IQR, 60.1-68.7]), the median OS (555 events; 88% mature) was 41.8 versus 37.7 months, respectively (HR, 0.80; 95% CI, 0.678 to 0.947; P = .0091). Eighty-six percent ( nab-paclitaxel + gemcitabine) and 68% (gemcitabine) of patients experienced grade ≥ 3 treatment-emergent adverse events. Two patients per study arm died of treatment-emergent adverse events. CONCLUSION The primary end point (independently assessed DFS) was not met despite favorable OS seen with nab-paclitaxel + gemcitabine.

4086 Background: Pemigatinib (PEMI), a potent, selective, oral FGFR1-3 inhibitor, has shown efficacy and safety in patients (pts) with CCA and FGFR2 rearrangements/fusions in FIGHT-202 (NCT02924376; objective response rate [ORR], 35.5%; duration of response [DOR], 7.2 months [mo]). Overall survival (OS: 21.1 mo) was not mature in the primary report (Abou-Alfa. Lancet Oncol 2020; cutoff: Mar 22, 2019); herein we report matured efficacy and safety data from FIGHT-202 (cutoff: Apr 7, 2020). Methods: Pts (≥18 y) with known FGF/FGFR alterations and progression after ≥1 prior therapy had FGFR2 rearrangements/fusions (cohort A), other FGF/FGFR alterations (B), or no FGF/FGFR alterations (C). Pts received PEMI 13.5 mg QD (21-d cycle; 2 wks on, 1 wk off) until progression or toxicity. Primary endpoint: independent, centrally confirmed ORR (cohort A); secondary endpoints: ORR (cohorts B, C; cohorts A and B combined); DOR, disease control rate (DCR), progression free survival (PFS), OS, and safety. A post-hoc analysis in cohort A evaluated mOS in responders (pts with complete response [CR] or partial response [PR]) vs non-responders (pts with progressive disease [PD] or stable disease (SD]). Results: At cutoff, 147 pts were enrolled (cohort A, n=108; B, n=20; C, n=17; FGF/FGFR status undetermined, n=2); median follow-up was 30.4 (range, 4.9–38.7) mo and median treatment duration was 5.9 (0.2–36.5) mo. In cohort A, 9.3% of pts remained on therapy at cutoff; in cohorts B and C, all pts had discontinued. Pts discontinued mainly for PD (67.6%, 75%, and 64.7% in cohorts A, B, and C respectively). Independent, centrally confirmed ORR was 37.0%; mOS was 17.5 mo (95% CI, 14.4-22.9) in cohort A (Table 1). mOS for responders (n=40) vs non-responders (n=68) was 30.1 (95% CI, 21.5-NE) mo vs 13.7 (9.6-16.1) mo. Overall, most common all-cause treatment-emergent adverse events (TEAEs) were hyperphosphatemia (58.5%; grade ≥3, 0%), alopecia (49.7%; 0%), diarrhea (46.9%; 3.4%), fatigue (43.5%; 5.4%), nausea (41.5%; 2%), and dysgeusia (40.8%; 0%); 10.2%, 13.6% and 42.2% of pts discontinued, had dose reduction, and treatment interruption due to TEAEs, respectively. Conclusions: These results reinforce the primary data, showing continued, durable responses and sustained tolerability in pts receiving PEMI for CCA harboring FGFR2 rearrangements/fusions. Notably, the matured OS is longer than historical data; OS for responders was more than twice as long vs for non-responders. Clinical trial information: NCT02924376. [Table: see text]

TPS4661 Background: Liposomal irinotecan administered with 5-fluorouracil/leucovorin (5-FU/LV) is approved in the USA for metastatic pancreatic ductal adenocarcinoma (mPDAC) following progression with gemcitabine-based therapy. A phase 1/2 study in previously untreated locally advanced/metastatic PDAC showed promising anti-tumor activity with liposomal irinotecan 50 mg/m2 free base + 5-FU 2400 mg/m2 + LV 400 mg/m2 + oxaliplatin (OX) 60 mg/m2 on days 1 and 15 of a 28-day cycle (Wainberg et al. Ann Oncol 2019;30 Suppl 4: SO-005). Herein, we present the design of the phase 3 NAPOLI-3 study investigating the efficacy and safety of this regimen as first-line therapy in patients with mPDAC. Methods: NAPOLI-3 (NCT04083235) is a phase 3, open-label, randomized, global study in adults with histologically/cytologically confirmed pancreatic adenocarcinoma not previously treated in the metastatic setting. Patients are required to have one or more metastatic tumors measurable with computed tomography/magnetic resonance imaging and an Eastern Cooperative Oncology Group performance status score of 0–1. Site activation began in Dec 2019 and enrollment is ongoing. Random allocation (1:1) of 750 patients is planned to liposomal irinotecan + 5-FU/LV + OX (regimen as per phase 1/2 study) or nab-paclitaxel 125 mg/m2 + gemcitabine 1000 mg/m2 on days 1, 8 and 15 in a 28-day cycle. The primary endpoint is overall survival (OS). Secondary endpoints (progression-free survival [PFS] and overall response rate assessed with Response Evaluation Criteria in Solid Tumors v1.1 criteria) will be compared only if the primary endpoint shows superiority for liposomal irinotecan + 5-FU/ LV + OX over nab-paclitaxel + gemcitabine. Safety assessments include adverse-event monitoring. Patients will continue treatment until disease progression, unacceptable toxicity or study withdrawal, and will then be followed for survival every 2 months until death or study end (when all patients have died, withdrawn consent or are lost to follow-up). Clinical trial information: NCT04083235 .