Hubbard, Joleen M.

126 Background: NNT/NNH analyses can estimate the magnitude of benefit vs harm of therapeutic agents and can inform clinical decision making. We quantified the benefit/risk profile of fruquintinib (F; a highly selective, oral inhibitor of all 3 VEGFRs) vs other later-line mCRC monotherapies. Methods: Six phase 3 randomized (2:1), placebo (P)-controlled trials (F: FRESCO, FRESCO-2; regorafenib [rego]: CONCUR, CORRECT; TAS-102: TERRA, RECOURSE) were identified. NNT (average number of pts needing treatment to prevent 1 additional death/progression event) for overall survival (OS) and progression-free survival (PFS) was calculated as the inverse of difference in survival function between treatment and P. NNH (average number of pts needing treatment for 1 additional pt to have an adverse event; AE) for treatment-emergent AEs (TEAEs) was calculated as the inverse of absolute risk increase relative to P. Low NNTs and high NNHs suggest a more favorable treatment profile. Results: F had the lowest NNT (most favorable) for 6-month OS (FRESCO-2) and PFS (FRESCO) vs rego and TAS-102 (Table). F had the highest NNH (most favorable) for grade ≥3 TEAEs, palmar-plantar erythrodysesthesia (PPE; FRESCO-2), and fatigue (FRESCO). TAS-102 (TERRA) had the highest NNH for diarrhea, followed by F (FRESCO-2). Consistent with mechanism of action of anti-VEGFRs, F and rego had lower NNHs for hypertension (HTN) vs TAS-102 (TERRA). F (FRESCO) had the lowest NNH for discontinuation due to TEAEs. Conclusions: In this cross-trial comparison, F had the lowest NNT for OS (FRESCO-2) and PFS (FRESCO/FRESCO-2), indicating survival benefit. F had the highest NNHs for grade ≥3 TEAEs, PPE (FRESCO-2), and fatigue (FRESCO), indicating a low risk profile. The analysis highlights fruquintinib as a favorable treatment for pts with mCRC. Clinical trial information: NCT02314819 , NCT04322539 , NCT01584830 , NCT01103323 , NCT01955837 , NCT01607957 . NNT/NNH (95% CI) for mCRC treatments.* F Rego TAS-102 FRESCO NCT02314819 N=416 FRESCO-2 NCT04322539 N=691 CONCUR NCT01584830 N=204 CORRECT NCT01103323 N=760 TERRA NCT01955837 N=406 RECOURSE NCT01607957 N=800 6-month OS 6.5(5.5–8.1) 5.3(4.8–5.9) 5.9(NA) 9.8(NA) 14.1(NA) 7.2(NA) 6-month PFS 4.2(3.7–4.8) 4.4(3.9–5.1) 5.0(NA) 9.1(NA) 7.1(NA) 7.2(NA) Grade ≥3 TEAEs 2.4 (2.0–3.1) 8.1 (5.0–22.5) 2.6 (2.0–3.7) 2.5 (2.2–3.0) 2.8 (2.3–3.6) 5.9 (4.1–10.2) TEAE leading to discontinuation 10.8 (6.7–28.5) NA † (18.0–NA) 12.5 (6.2–NA) 17.5(11.3–39.2) 250.0 (15.3–NA) 50.0 (22.9–NA) PPE 2.2 (1.9–2.5) 6.0 (4.8–8.0) 1.4 (1.3–1.7) 2.6 (2.2–3.0) NA (NA) NA (46.0–NA) HTN 2.4 (2.0–3.0) 3.6 (3.0–4.5) 5.3 (3.6–9.5) 4.5 (3.7–5.8) 14.3 (10.0–25.2) NA (NA) Diarrhea 5.1 (3.8–7.4) 7.3 (5.2–12.3) 6.2 (4.3–11.4) 3.8 (3.2–4.8) 7.9 (5.7–13.0) 5.0 (3.9–6.9) Fatigue 32.5 (10.3–NA) 25.8 (10.1–NA) 10 (5.3–80.3) 5.3 (3.8–8.4) 7.4 (5.0–13.9) 8.3 (5.4–18.1) *All trials except TERRA included best supportive care in both arms. † Lower rate of pts discontinued F vs P due to TEAEs, thus NNH was not applicable (NA).

PURPOSE Immunotherapy has demonstrated limited efficacy in the treatment of microsatellite-stable (MSS) metastatic colorectal cancer (mCRC) to date. We evaluated whether an off-the-shelf, multipeptide vaccine, PolyPEPI1018, in conjunction with standard chemotherapy can induce broad antitumor immune responses, potentially improving disease control in refractory mCRC. PATIENTS AND METHODS This single-arm, open-label study enrolled adults with MSS mCRC who had progressed after ≤2 previous lines of therapy for metastatic disease. PolyPEPI1018 was administered subcutaneously to four anatomical sites on days 1 and 15 and TAS-102 orally twice a day on days 1-5 and 8-12 of a 28-day cycle. Patients were treated for seven cycles or until disease progression. The primary end point was safety. Secondary end points were overall response rate, progression-free survival (PFS), overall survival (OS), and immune and genetic correlates. RESULTS Fifteen patients were enrolled; 80% had liver metastases and 67% had KRAS mutations. Adverse events (AEs) related to PolyPEPI1018 were grade 1 and 2 local skin reactions (n = 14). Grade 3 AEs (n = 15) at least possibly related to treatment were fatigue, decreased lymphocyte and neutrophil counts, and diarrhea. None had objective tumor response; the disease control rate was 53.3%. The median PFS (mPFS) was 4.0 (95% CI, 2.2 to 6.1) months and the median OS (mOS) was 8.7 (95% CI, 6.4 to 15.2) months. In post hoc subgroup analyses, patients without active liver metastasis had improved mPFS of 9.7 months and mOS of 14.8 months. In addition, patients who were predicted to have broader immune responses to vaccine based on human leukocyte antigen genotype had longer mOS (10.3 v 4.6 months, hazard ratio, 0.29 [95% CI, 0.07 to 1.17]). CONCLUSION The addition of PolyPEPI1018 to TAS-102 was safe and induced immunological responses that were associated with improved clinical outcomes. Further investigation of this chemo-immunotherapeutic is warranted.

PURPOSE Colorectal cancer (CRC) incidence and mortality have decreased since the 1970s, but the incidence in young adults (<50 years, named early-onset CRC [eoCRC]) has been increasing. PATIENTS AND METHODS Individual patient data on 13,365 patients with metastatic CRC enrolled between 2000 and 2012 in 17 first-line randomized trials in the Aide et Recherche en Cancérologie Digestive database were pooled. The distribution of demographics, clinicopathologic features, biomarkers, and outcome data were summarized and compared by age groups. Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for potential confounders. Predictive value of age group on clinical outcomes was evaluated by testing interaction effect between treatment and age variables. RESULTS Overall, 2,045 patients with eoCRC (median age, 42.5) and 11,320 patients with average-onset CRC (aoCRC; median age, 63.8) were included in this analysis. Within the eoCRC population, treatment with bevacizumab in addition to chemotherapy improved PFS (9.9 v 6.8 months; hazard ratio [HR], 0.66 [95% CI, 0.54 to 0.80]; P < .0001), which was similar to the findings in aoCRC population (9.4 v 7.3 months; HR, 0.73 [95% CI, 0.67 to 0.80]; P < .001; interaction P = .5415). However, epithelial growth factor receptor inhibitor (EGFRi) did not improve PFS in RAS wild-type (WT) patients with eoCRC who had left-sided primary tumors (8.3 v 8.9 months; HR, 1.20 [95% CI, 0.81 to 1.77]; P = .36), whereas EGFRi significantly improved PFS in the aoCRC population (9.9 v 8.5 months; HR, 0.74 [95% CI, 0.64 to 0.86]; P < .0001; interaction P = .083). CONCLUSION Treatment-naïve patients with metastatic eoCRC appear to derive similar benefit from bevacizumab as patients with aoCRC. However, patients with eoCRC with left-sided RAS/RAF WT tumors did not appear to derive benefit from first-line EGFRi.

Abstract Background FGFR alterations are known to be driver alterations in several tumor types. We aimed to assess the efficacy of pemigatinib, an oral FGFR1-3 inhibitor, in patients with metastatic or unresectable colorectal cancer whose tumors harbored FGF/FGFR alterations. Patients and Methods The ACCRU-GI-1701 is a single-arm phase II trial which enrolled patients with previously treated FGF/FGFR-altered metastatic colorectal cancer to receive oral pemigatinib daily in 21-day cycles. The primary endpoint is objective response. Secondary endpoints include clinical benefit, progression-free survival, overall survival, quality of life, and adverse events (AEs). This trial was registered with ClinicalTrials.gov (NCT04096417). Results Of the 14 patients included in the interim analysis, the objective response rate as well as clinical benefit rate were 0%. Given these results, the trial closed to enrollment after stage one due to futility. A total of 42.9% of patients had at least one grade 3 or higher AE, the most common being anemia and fatigue. Conclusion Pemigatinib monotherapy did not lead to objective responses in patients with chemorefractory metastatic colorectal cancer harboring FGF/FGFR alterations, although it was overall relatively well tolerated with no new safety signals. Notably, 93% (n = 13) of patients had only FGF/FGFR mutations and amplifications; one patient had an FGFR3-WHSC1 fusion at a low cfDNA percentage (0.02%).

Background Novel treatment options are required in patients with platinum-resistant ovarian cancer (PROC). Myeloid-derived suppressor cells promote a hostile tumor microenvironment and are associated with worse clinical outcomes in PROC. We evaluated the safety and preliminary efficacy of PY159, an agonist antibody to Triggering receptor expressed on myeloid cells-1 (TREM1) that reprograms immunosuppressive intratumoral myeloid cells, and PY314, an antagonist antibody to Triggering receptor expressed on myeloid cells-2 (TREM2) that depletes tumor-associated macrophages, as single agents and in combination with pembrolizumab in subjects with PROC. Methods PY159 and PY314 were individually evaluated in patients with PROC. Patients were treated with monotherapy (PY159 3 mg/kg or PY314 10 mg/kg), based on the recommended dose for expansion derived from the phase 1a studies. At the time of first progression, patients could continue study drug and crossover to combination therapy with pembrolizumab (200 mg) every 3 weeks at the discretion of the investigator. Disease assessment by Response Evaluation Criteria in Solid Tumor version 1.1 was performed every 6 weeks. Results 17 patients were enrolled in the PY159 study (median age 67, range 22–77; median prior therapies 6, range 2–18) and 16 patients in PY314 (median age 65.5, range 49–81; median prior therapies 4, range 2–10). 7 patients in PY159 and 8 patients in PY314 crossed over to combination therapy. Safety events included the following: treatment-related adverse events occurred in 15 patients (88.2%) in PY159 and 9 patients (56.3%) in PY314. Infusion-related reactions occurred in 6 patients (35.3%) in PY159 and 3 patients (18.8%) in PY314. Immune-related adverse events occurred in 13 patients (76.5%) in PY159 (arthralgias) and 1 patient (6.3%) in PY314 (diarrhea). Serious adverse events occurred in 6 patients (36.3%) in PY159 (1 related) and 12 patients (75%) in PY314 (all unrelated). The best radiographic response in PY159 was stable disease in 8/16 patients (50%; median 16 weeks, range 9–33), and in PY314, it was stable disease in 8/16 patients (50%; median 12 weeks, range 6–36). Median PFS was 2.76 months and 2.69 months in PY159 and PY314, respectively. There were no responses in the crossover arm. Conclusions Both PY159 and PY314 were well tolerated, with an acceptable safety profile, as both single agents and in combination with pembrolizumab. Both agents warrant further investigation in heavily pretreated PROC.

In a retrospective study of patients with Lynch syndrome vs non‐Lynch syndrome and microsatellite instability high colorectal cancer, there were no observed differences with immune checkpoint inhibitors toward progression‐free survival or overall survival. Univariate analysis of Stage IV patients showed BRAF V600E mutations were associated with decreased survival.

PURPOSE This phase II study evaluated the efficacy and tolerability of onvansertib, a polo-like kinase 1 (PLK1) inhibitor, in combination with fluorouracil, leucovorin, and irinotecan (FOLFIRI) + bevacizumab for the second-line treatment of KRAS -mutant metastatic colorectal cancer (mCRC). PATIENTS AND METHODS This multicenter, open-label, single-arm study enrolled patients with KRAS -mutated mCRC previously treated with oxaliplatin and fluorouracil with or without bevacizumab. Patients received onvansertib (15 mg/m 2 once daily on days 1-5 and 15-19 of a 28-day cycle) and FOLFIRI + bevacizumab (days 1 and 15). The primary end point was the objective response rate (ORR), and secondary endpoints included progression-free survival (PFS), duration of response (DOR), and tolerability. Translational and preclinical studies were conducted in KRAS -mutant CRC. RESULTS Among the 53 patients treated, the confirmed ORR was 26.4% (95% CI, 15.3 to 40.3). The median DOR was 11.7 months (95% CI, 9.4 to not reached). Grade 3/4 adverse events were reported in 62% of patients. A post hoc analysis revealed that patients with no prior bevacizumab treatment had a significantly higher ORR and longer PFS compared with patients with prior bevacizumab treatment: ORR of 76.9% versus 10.0% (odds ratio of 30.0, P < .001) and median PFS of 14.9 months versus 6.6 months (hazard ratio of 0.16, P < .001). Our translational findings support that prior bevacizumab exposure contributes to onvansertib resistance. Preclinically, we showed that onvansertib inhibited the hypoxia pathway and exhibited robust antitumor activity in combination with bevacizumab through the inhibition of angiogenesis. CONCLUSION Onvansertib in combination with FOLFIRI + bevacizumab showed significant activity in the second-line treatment of patients with KRAS -mutant mCRC, particularly in patients with no prior bevacizumab treatment. These findings led to the evaluation of the combination in the first-line setting (ClinicalTrails.gov identifier: NCT06106308 ).

Aim: The objective of this study was to compare adverse event (AE) management costs for fruquintinib, regorafenib, trifluridine/tipiracil (T/T) and trifluridine/tipiracil+bevacizumab (T/T+bev) for patients with metastatic colorectal cancer (mCRC) previously treated with at least two prior lines of therapy from the US commercial and Medicare payer perspectives. Materials & methods: A cost-consequence model was developed to calculate the per-patient and per-patient-per-month (PPPM) AE costs using rates of grade 3/4 AEs with incidence ≥5% in clinical trials, event-specific management costs and duration treatment. Anchored comparisons of AE costs were calculated using a difference-in-differences approach with best supportive care (BSC) as a common reference. AE rates and treatment duration were obtained from clinical trials: FRESCO and FRESCO-2 (fruquintinib), RECOURSE (T/T), CORRECT (regorafenib) and SUNLIGHT (T/T, T/T+bev). AE management costs for the commercial and Medicare perspectives were obtained from publicly available sources. Results: From the commercial perspective, the AE costs (presented as per-patient, PPPM) were: $4015, $1091 for fruquintinib (FRESCO); $4253, $1390 for fruquintinib (FRESCO-2); $17,110, $11,104 for T/T (RECOURSE); $9851, $4691 for T/T (SUNLIGHT); $8199, $4823 for regorafenib; and $11,620, $2324 for T/T+bev. These results were consistent in anchored comparisons: the difference-in-difference for fruquintinib based on FRESCO was -$1929 versus regorafenib and -$11,427 versus T/T; for fruquintinib based on FRESCO-2 was -$2257 versus regorafenib and -$11,756 versus T/T. Across all analyses, results were consistent from the Medicare perspective. Conclusion: Fruquintinib was associated with lower AE management costs compared with regorafenib, T/T and T/T+bev for patients with previously treated mCRC. This evidence has direct implications for treatment, formulary and pathways decision-making in this patient population.

3579 Background: Fruquintinib (F) is a highly selective, oral tyrosine kinase inhibitor of all 3 VEGF receptors. Based on FRESCO (NCT02314819) and FRESCO-2 (NCT04322539) data, F was approved by the US FDA for previously treatedmetastatic colorectal cancer (mCRC). Efficacy and safety of F + best supportive care (BSC) vs placebo (P) + BSC were analyzed according to prior treatment (tx) sequence using FRESCO and FRESCO-2 data. Methods: In FRESCO and FRESCO-2, patients (pts) were randomized 2:1 to receive F 5 mg or matching P, PO daily x 21 days every 28 days. In FRESCO, eligible pts had received ≥2 prior chemotherapy regimens and were permitted to have received prior anti-VEGF and/or anti-EGFR therapies, whereas in FRESCO-2, in addition to standard chemotherapies, anti-VEGF, and anti-EGFR therapies if indicated, prior exposure to trifluridine/tipiracil (TAS) and/or regorafenib (rego) was required. FRESCO-2 pts must have also received a BRAF inhibitor and/or immunotherapy, if indicated and available in their country. Results: In FRESCO (F n=278 vs P n=138), no pts had received rego and 16/416 pts (4%) had received TAS. InFRESCO-2, prior therapies were balanced between F vs P arms; pts had received prior TAS or rego in these sequences: prior TAS only (n=240 vs n=121); prior rego only (n=40 vs n=18); prior rego then TAS (n=84 vs n=45); prior TAS then rego (n=95 vs n=44). Improvements in OS and PFS were seen with F vs P regardless of prior tx sequence (Table), with similar magnitudes of benefit for OS (HRs 0.53–0.77) and PFS (HRs 0.25–0.37). F safety profile was consistent regardless of prior tx sequence (Table). Conclusions: F is effective in mCRC with a manageable safety profile regardless of prior TAS or rego tx and sequence. Improvement with F was similar for OS and PFS despite the number and sequence of prior regimens. F provides a new tx option for pts with previously treated mCRC regardless of prior TAS or rego exposure. Clinical trial information: NCT04322539 . [Table: see text]

3594 Background: The efficacy of checkpoint inhibitor immunotherapy in MSI-H mCRC has not been replicated in MSS mCRC. Therefore, additional interventions are needed to convert immunologically “cold” MSS CRC to “hot” tumors resembling MSI-H tumors. PolyPEPI1018 is an off-the-shelf, multi-peptide vaccine containing 12 immunogenic epitopes derived from 7 shared tumor antigens which demonstrated early evidence of clinical activity in first-line MSS mCRC. Methods: Patients with MSS mCRC who have progressed on 2-3 lines of prior chemotherapy regimen received PolyPEPI1018 (1.2 mg, sc) and atezolizumab (1,200 mg, iv) Q3W until disease progression or unacceptable toxicity. The primary endpoint was safety. A Simon 2-stage design was applied. Data on objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and correlation studies will be presented. Results: 18 patients (66 % female) were enrolled for stage 1 of the study. Median age was 54 years (range 38–79), 50% had liver metastases and 67% received at least 3 lines of prior therapies. PD-L1 expression was <1% for 85% of patients. The combination was well-tolerated; most common side effect related to treatment was Grade (Gr) 1-2 local skin reaction (n=22). Gr 2 events (n=2) at least possibly related to treatment were nausea, pyrexia and increased blood alkaline phosphatase. There were no Gr 3-5 events or study discontinuation due to treatment AE. The ORR was 0% and the DCR was 61%. The mPFS was 2.7 months (95%CI 1.4-4.0) and the mOS was not reached (95%CI 8.75 – NE months) at the data cut-off date. Ex-vivo FluoroSpot identified 13/16 subjects with robust, vaccine-specific CD8+ and/or CD4+ T cell responses detected against multiple vaccine antigens. For patients with available biopsy pairs (n=8), both the average PD-L1 expression (IC%, p=0.029) and the density of CD8+ tumor-infiltrating lymphocytes (TILs, p=0.019) were significantly increased, post-treatment. Patients with increased PFS (> 12 weeks) had both higher levels of post-treatment PD-L1 (p=0.007) and TILs (p=0.016) than patients with PFS ≤ 12 weeks. Conclusions: PolyPEPI1018 in combination with atezolizumab was well-tolerated with no Grade 3 AEs observed. Despite no objective tumor responses could be detected, correlative data suggest contribution of PolyPEPI1018-induced immune responses to the modulation of tumor microenvironment and to improved disease control. The study did not proceed to stage 2; it is on-going for the collection of survival data. Clinical trial information: NCT05243862 .