Raheel Nathani

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. We report 3-year efficacy and safety results from the phase III CheckMate 649 trial. Patients with previously untreated advanced or metastatic gastroesophageal adenocarcinoma were randomly assigned to nivolumab plus chemotherapy or chemotherapy. Primary end points were overall survival (OS) and progression-free survival (PFS) by blinded independent central review (BICR) in patients whose tumors expressed PD-L1 combined positive score (CPS) ≥5. With 36.2-month minimum follow-up, for patients with PD-L1 CPS ≥5, the OS hazard ratio (HR) for nivolumab plus chemotherapy versus chemotherapy was 0.70 (95% CI, 0.61 to 0.81); 21% versus 10% of patients were alive at 36 months, respectively; the PFS HR was 0.70 (95% CI, 0.60 to 0.81); 36-month PFS rates were 13% versus 8%, respectively. The objective response rate (ORR) per BICR was 60% (95% CI, 55 to 65) with nivolumab plus chemotherapy versus 45% (95% CI, 40 to 50) with chemotherapy; median duration of response was 9.6 months (95% CI, 8.2 to 12.4) versus 7.0 months (95% CI, 5.6 to 7.9), respectively. Nivolumab plus chemotherapy also continued to show improvement in OS, PFS, and ORR versus chemotherapy in the overall population. Adding nivolumab to chemotherapy maintained clinically meaningful long-term survival benefit versus chemotherapy alone, with an acceptable safety profile, supporting the continued use of nivolumab plus chemotherapy as standard first-line treatment for advanced gastroesophageal adenocarcinoma.

Patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) primary breast cancer (BC) have low pathological complete response (pCR) rates with neoadjuvant chemotherapy. A subset of ER+/HER2- BC contains dense lymphocytic infiltration. We hypothesized that addition of an anti-programmed death 1 agent may increase pCR rates in this BC subtype. We conducted a randomized, multicenter, double-blind phase 3 trial to investigate the benefit of adding nivolumab to neoadjuvant chemotherapy in patients with newly diagnosed, high-risk, grade 3 or 2 (ER 1 to ≤10%) ER+/HER2- primary BC. In total, 510 patients were randomized to receive anthracycline and taxane-based chemotherapy with either intravenous nivolumab or placebo. The primary endpoint of pCR was significantly higher in the nivolumab arm compared with placebo (24.5% versus 13.8%; P = 0.0021), with greater benefit observed in patients with programmed death ligand 1-positive tumors (VENTANA SP142 ≥1%: 44.3% versus 20.2% respectively). There were no new safety signals identified. Of the five deaths that occurred in the nivolumab arm, two were related to study drug toxicity; no deaths occurred in the placebo arm. Adding nivolumab to neoadjuvant chemotherapy significantly increased pCR rates in high-risk, early-stage ER+/HER2- BC, particularly among patients with higher stromal tumor-infiltrating lymphocyte levels or programmed death ligand 1 expression, suggesting a new treatment paradigm that emphasizes the role of immunotherapy and T cell immunosurveillance in luminal disease. Clinical trials.gov identifier: NCT04109066.

Abstract Background: CheckMate 7FL (CM 7FL; NCT04109066) is a prospective, phase 3, randomized, multicenter, double-blind trial investigating nivolumab (NIVO) in combination with neoadjuvant chemotherapy (NACT) and adjuvant endocrine therapy (ET) in patients (pts) with high-risk, estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2−) primary breast cancer (BC). The primary endpoint (pathological complete response, pCR) was met, resulting in a statistically significant improvement with added NIVO to NACT; residual cancer burden (RCB) 0–1 rate was meaningfully improved. NIVO benefit was larger in pts with PD-L1+ tumors (SP142 assay, % immune cells ≥ 1%). This analysis focuses on additional biomarkers to explore associations with NIVO treatment effect. Methods: The study enrolled newly diagnosed pts, stages T1c–2 N1–2 or T3–4 N0–2, grade 2 (ER 1–‍10%) or 3 (ER ≥ 1%). Pts were randomized 1:1 to NACT + NIVO 360 mg Q3W/NIVO 240 mg Q2W (arm A) or NACT + placebo (PBO; arm B). Clinical efficacy data included pCR (ypT0/is ypN0) and RCB 0–1 rates in the modified ITT (mITT) population and the SP142 PD-L1+ subgroup. Baseline PD-L1 expression from core biopsies was evaluated with the Dako 28-8 assay using the combined positive score (CPS) algorithm. Various cutoffs (CPS ≥ 1, 10, and 20) were used for this exploration. Concordance between PD-L1 SP142 and 28-8 CPS was evaluated, with assays performed on different slides from the same tumor biopsy blocks. Results of efficacy by ER and/or progesterone receptor (PR) expression, as well as Ki67 index and stromal tumor-infiltrating lymphocytes, will be presented at the meeting. Results: Overall, 830 pts were screened, 521 randomized, and 517 treated, with the primary efficacy population (mITT; n = 510) including all randomized pts but excluding 11 pts from Russian sites with insufficient follow-up. A total of 510 and 349 pts (68.4% of mITT population) were evaluated by PD-L1 SP142 and 28-8 CPS assays, respectively. The prevalence of PD-L1+ by CPS was balanced in arms A and B (52% vs 50% had CPS ≥ 1; 19% vs 16% had CPS ≥ 10, and 11% vs 9% had CPS ≥ 20, respectively). NIVO effect was larger in pts with tumors with increasing PD-L1 expression, with a ∆pCR rate (unweighted rate difference between arms A and B) of 16.6% in CPS ≥ 1 (40.4% vs 23.8% in arms A/B; 95% CI, 2.8 to 29.4), 32.4% in CPS ≥ 10 (65.7% vs 33.3% in arms A/B; 95% CI, 7.3 to 52.3), and 52.3% in CPS ≥ 20 (78.9% vs 26.7% in arms A/B; 95% CI, 18.6 to 72.4). In comparison, the ∆pCR rate was 10.7% in the mITT population (24.5% vs 13.8% in arms A/B; 95% CI, 3.9 to 17.4) and 5.7% in pts with CPS < 1 (14.0% vs 8.2% in arms A/B; 95% CI, -4.0 to 15.5; refer to the Table for additional details). Unweighted rate differences between arms A and B for RCB 0–1 (∆RCB 0–1 rate) followed a similar trend and were observed to be 17.0% in CPS ≥ 1, 34.4% in CPS ≥ 10, and 52.3% in CPS ≥ 20. In comparison, the ∆RCB 0–1 rate was 9.4% in the mITT population and 3.3% in pts with CPS < 1 (refer to the Table for additional details). Further biomarker data and cutoffs will be presented at the meeting. Conclusions: Greater PD-L1 expression was associated with higher pCR and RCB 0–1 rates, suggesting that pts with PD-L1+, high-risk, ER+/HER2− primary BC can achieve substantial pCR rates with the addition of NIVO to NACT. Table. Summary pCR and RCB 0–1 rates by PD-L1 SP142 and 28-8 CPS at various cutoffs. Note: CPS data with the cutoff at 5 will be presented at the meeting. Citation Format: Sherene Loi, Giuseppe Curigliano, Roberto Salgado, Roberto Iván Romero Díaz, Suzette Delaloge, Carlos Ignacio Rojas García, Marleen Kok, Cristina Saura, Nadia Harbeck, Elizabeth Mittendorf, Denise Yardley, Lajos Pusztai, Alberto Suárez Zaizar, Andrei Ungureanu, Felipe Ades, Rajalakshmi Chandra, Raheel Nathani, Misena Pacius, Thomas Spires, Jenny Wu, Heather McArthur. Biomarker Results in High-risk Estrogen Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Primary Breast Cancer Following Neoadjuvant Chemotherapy ± Nivolumab: an Exploratory Analysis of CheckMate 7FL [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-01.

306 Background: NIVO + chemo demonstrated superior overall survival (OS) and clinically meaningful progression-free survival (PFS) benefit vs chemo and an acceptable safety profile in previously untreated, advanced non-HER2+ GC/GEJC/EAC, leading to approvals in many countries. NIVO + chemo continued to demonstrate clinically meaningful improvement in efficacy at 2 and 3-yr follow-ups. We present 4-yr follow-up results for NIVO + chemo vs chemo from CheckMate 649. Methods: Adults with previously untreated, unresectable advanced, or metastatic GC/GEJC/EAC were enrolled, regardless of programmed death ligand 1 (PD-L1) expression. HER2+ patients (pts) were excluded. Randomized pts received NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: 1581 pts were randomized to NIVO + chemo or chemo. At the 48-month (mo) minimum follow-up, NIVO + chemo continued to demonstrate OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table) OS benefit with NIVO + chemo was observed in most prespecified subgroups. Objective response rates (ORR) were higher and responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table). In the exploratory analysis of OS by response at the 18-week landmark timepoint, there were numerically more pts achieving response with NIVO + chemo vs chemo, and median OS (95% CI) with NIVO + chemo was numerically longer in responders vs non-responders both in pts with PD-L1 CPS ≥ 5 (20.5 [17.5–25.0] vs 14.0 [11.6–15.7]) and all randomized pts (19.4 [17.5–21.7] vs 13.1 [11.6–14.4]). No new safety signals were identified, consistent with the 3-yr follow-up. Conclusions: NIVO + chemo is the first PD-1 inhibitor/chemo combination to demonstrate long-term efficacy and acceptable safety after 4 yrs of follow up in previously untreated advanced GC/GEJC/EAC. These results are consistent with earlier follow-ups, further supporting NIVO + chemo as a standard 1L treatment in these pts. Clinical trial information: NCT02872116 .[Table: see text]