Novel antibody-drug conjugates against HER2 are showing high activity in HER2-negative breast cancer (BC) with low HER2 expression (i.e., 1+ or 2+ and lack of ERBB2 amplification). However, the clinical and molecular features of HER2-low BC are yet to be elucidated. Here, we collected retrospective clinicopathological and PAM50 data from 3,689 patients with HER2-negative disease and made the following observations. First, the proportion of HER2-low was higher in HR-positive disease (65.4%) than triple-negative BC (TNBC, 36.6%). Second, within HR-positive disease, ERBB2 and luminal-related genes were more expressed in HER2-low than HER2 0. In contrast, no gene was found differentially expressed in TNBC according to HER2 expression. Third, within HER2-low, ERBB2 levels were higher in HR-positive disease than TNBC. Fourth, HER2-low was not associated with overall survival in HR-positive disease and TNBC. Finally, the reproducibility of HER2-low among pathologists was suboptimal. This study emphasizes the large biological heterogeneity of HER2-low BC, and the need to implement reproducible and sensitive assays to measure low HER2 expression.

Breast cancer represents an urgent global priority. While this is a universal issue, and as the burden of the disease is increasing globally, current estimates indicate that in the next couple of decades, much of the incidence and mortality related to breast cancer will be seen in underserved populations. The fragile and ill-prepared healthcare systems in low- and middle-income countries (LMIC) need to address this challenge and find solutions with their limited resources. Significant disparities can be identified in stage at presentation as the ability to detect the disease in earlier stages is compromised in these scenarios leading to worse outcomes associated to late diagnoses. Furthermore, access to healthcare in general and to basic surgical, radiotherapy and systemic care is suboptimal additionally limiting treatment results. With a small portion of their budget allocated to healthcare, LMIC need to make the most of their resources prioritizing cost-effective strategies that could offer the best possible results. Countries that invest in women's health do develop into healthier, more educated, and importantly, more productive societies with benefits seen across generations. Finally, recognition of inequities should stimulate a concerted effort engaging all involved stakeholders to find context-adapted solutions to improve healthcare outcomes.

PURPOSE: In extensive-disease small-cell lung cancer (ED-SCLC), response rates to first-line platinum-based chemotherapy are robust, but responses lack durability. CheckMate 451, a double-blind phase III trial, evaluated nivolumab plus ipilimumab and nivolumab monotherapy as maintenance therapy following first-line chemotherapy for ED-SCLC. METHODS: Patients with ED-SCLC, Eastern Cooperative Oncology Group performance status 0-1, and no progression after ≤ 4 cycles of first-line chemotherapy were randomly assigned (1:1:1) to nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks for 12 weeks followed by nivolumab 240 mg once every 2 weeks, nivolumab 240 mg once every 2 weeks, or placebo for ≤ 2 years or until progression or unacceptable toxicity. Primary end point was overall survival (OS) with nivolumab plus ipilimumab versus placebo. Secondary end points were hierarchically tested. RESULTS: Overall, 834 patients were randomly assigned. The minimum follow-up was 8.9 months. OS was not significantly prolonged with nivolumab plus ipilimumab versus placebo (hazard ratio [HR], 0.92; 95% CI, 0.75 to 1.12; P = .37; median, 9.2 v 9.6 months). The HR for OS with nivolumab versus placebo was 0.84 (95% CI, 0.69 to 1.02); the median OS for nivolumab was 10.4 months. Progression-free survival HRs versus placebo were 0.72 for nivolumab plus ipilimumab (95% CI, 0.60 to 0.87) and 0.67 for nivolumab (95% CI, 0.56 to 0.81). A trend toward OS benefit with nivolumab plus ipilimumab was observed in patients with tumor mutational burden ≥ 13 mutations per megabase. Rates of grade 3-4 treatment-related adverse events were nivolumab plus ipilimumab (52.2%), nivolumab (11.5%), and placebo (8.4%). CONCLUSION: Maintenance therapy with nivolumab plus ipilimumab did not prolong OS for patients with ED-SCLC who did not progress on first-line chemotherapy. There were no new safety signals.

This multicenter, randomized, open-label phase III trial (planned enrollment: 700 patients) was conducted to test the hypothesis that single-agent sunitinib improves progression-free survival (PFS) compared with capecitabine as treatment for advanced breast cancer (ABC). Patients with HER2-negative ABC that recurred after anthracycline and taxane therapy were randomized (1:1) to sunitinib 37.5 mg/day or capecitabine 1,250 mg/m² (1,000 mg/m² in patients >65 years) BID on days 1–14 q3w. The independent data-monitoring committee (DMC) determined during the first interim analysis (238 patients randomized to sunitinib, 244 to capecitabine) that the trial be terminated due to futility in reaching the primary endpoint. No statistical evidence supported the hypothesis that sunitinib improved PFS compared with capecitabine (one-sided P = 0.999). The data indicated that PFS was shorter with sunitinib than capecitabine (median 2.8 vs. 4.2 months, respectively; HR, 1.47; 95% CI, 1.16–1.87; two-sided P = 0.002). Median overall survival (15.3 vs. 24.6 months; HR, 1.17; two-sided P = 0.350) and objective response rates (11 vs. 16%; odds ratio, 0.65; P = 0.109) were numerically inferior with sunitinib versus capecitabine. While no new or unexpected safety findings were reported, sunitinib treatment was associated with higher frequencies and greater severities of many common adverse events (AEs) compared with capecitabine, resulting in more temporary discontinuations due to AEs with sunitinib (66 vs. 51%). The relative dose intensity was lower with sunitinib than capecitabine (73 vs. 95%). Based on these efficacy and safety results, sunitinib should not be used as monotherapy for patients with ABC.

PURPOSE: Combining standard of care (pertuzumab-trastuzumab [PH], chemotherapy) with cancer immunotherapy may potentiate antitumor immunity, cytotoxic activity, and patient outcomes in high-risk, human epidermal growth factor receptor 2 (HER2)–positive early breast cancer. We report the phase III IMpassion050 primary analysis of neoadjuvant atezolizumab, PH, and chemotherapy in these patients. METHODS: Patients with a primary tumor of > 2 cm and histologically confirmed, positive lymph node status (T2-4, N1-3, M0) were randomly assigned 1:1 to atezolizumab/placebo with dose-dense doxorubicin/cyclophosphamide, followed by paclitaxel, and PH. After surgery, patients were to continue atezolizumab/placebo and PH (total: 1 year of HER2-targeted therapy); those with residual disease could switch to ado-trastuzumab emtansine with atezolizumab/placebo. Coprimary efficacy end points were pathologic complete response (pCR; ypT0/is ypN0) rates in intention-to-treat (ITT) and programmed cell death-ligand 1 (PD-L1)–positive populations. RESULTS: At clinical cutoff (February 5, 2021), pCR rates in the placebo and atezolizumab groups in the ITT populations were 62.7% (n = 143/228) and 62.4% (n = 141/226), respectively (difference –0.33%; 95% CI, –9.2 to 8.6; P = .9551). The pCR rates in the placebo and atezolizumab groups in patients with PD-L1–positive tumors were 72.5% (n = 79/109) and 64.2% (n = 70/109), respectively (difference –8.26%; 95% CI, –20.6 to 4.0; P = .1846). Grade 3-4 and serious adverse events were more frequent in the atezolizumab versus placebo group. Five grade 5 adverse events occurred (four neoadjuvant, one adjuvant; two assigned to study treatment), all with atezolizumab. Overall, the safety profile was consistent with that of atezolizumab in other combination studies. CONCLUSION: Atezolizumab with neoadjuvant dose-dense doxorubicin/cyclophosphamide–paclitaxel and PH for high-risk, HER2-positive early breast cancer did not increase pCR rates versus placebo in the ITT or PD-L1–positive populations. PH and chemotherapy remains standard of care; longer follow-up may help to inform the long-term impact of atezolizumab.