Ado-trastuzumab emtansine (T-DM1) in patients with HER2-amplified tumors excluding breast and gastric/gastroesophageal junction (GEJ) adenocarcinomas: results from the NCI-MATCH trial (EAY131) subprotocol Q.

BACKGROUND: The National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH) is a national precision medicine study incorporating centralized genomic testing to direct refractory cancer patients to molecularly targeted treatment subprotocols. This treatment subprotocol was designed to screen for potential signals of efficacy of ado-trastuzumab emtansine (T-DM1) in HER2-amplified histologies other than breast and gastroesophageal tumors. METHODS: Eligible patients had HER2 amplification at a copy number (CN) >7 based on targeted next-generation sequencing (NGS) with a custom Oncomine AmpliSeq™ (ThermoFisher Scientific) panel. Patients with prior trastuzumab, pertuzumab or T-DM1 treatment were excluded. Patients received T-DM1 at 3.6 mg/kg i.v. every 3 weeks until toxicity or disease progression. Tumor assessments occurred every three cycles. The primary end point was centrally assessed objective response rate (ORR). Exploratory end points included correlating response with HER2 CN by NGS. The impact of co-occurring genomic alterations and PTEN loss by immunohistochemistry were also assessed. RESULTS: Thirty-eight patients were enrolled and 36 included in efficacy analysis. Median prior therapies in the metastatic setting was 3 (range 0-9; unknown in one patient). Median HER2 CN was 17 (range 7-139). Partial responses were observed in two (5.6%) patients: one mucoepidermoid carcinoma of parotid gland and one parotid gland squamous cell cancer. Seventeen patients (47%) had stable disease including 8/10 (80%) with ovarian and uterine carcinomas, with median duration of 4.6 months. The 6-month progression-free survival rate was 23.6% [90% confidence interval 14.2% to 39.2%]. Common toxicities included fatigue, anemia, fever and thrombocytopenia with no new safety signals. There was a trend for tumor shrinkage with higher levels of gene CN as determined by the NGS assay. CONCLUSION: T-DM1 was well tolerated. While this subprotocol did not meet the primary end point for ORR in this heavily pre-treated diverse patient population, clinical activity was seen in salivary gland tumors warranting further study in this tumor type in dedicated trials.

Capivasertib and fulvestrant for patients with hormone receptor-positive advanced breast cancer: characterization, time course, and management of frequent adverse events from the phase III CAPItello-291 study.

BACKGROUND: Capivasertib is a potent, selective pan-AKT inhibitor. In CAPItello-291, the addition of capivasertib to fulvestrant resulted in a statistically significant (P < 0.001) improvement in progression-free survival over fulvestrant monotherapy in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer and disease progression on or after aromatase inhibitor-based therapy. Characterization of the capivasertib-fulvestrant adverse event (AE) profile as managed in CAPItello-291 can inform future management guidance and optimize clinical benefit. PATIENTS AND METHODS: Seven hundred and eight patients were randomized 1 : 1 to capivasertib (400 mg twice daily; 4 days on, 3 days off) or placebo, plus fulvestrant, on a 4-week cycle. Dose reductions/interruptions for capivasertib/placebo were permitted (up to two dose reductions). Safety analyses included exposure, AE, and clinical laboratory data and were conducted in patients who received at least one dose of capivasertib, fulvestrant, or placebo. Frequent AEs associated with phosphoinositide 3-kinase (PI3K)/protein kinase (AKT) pathway inhibition (diarrhea, rash, hyperglycemia) were characterized using group terms. AEs were summarized using descriptive statistics; time-to-event analyses were conducted. RESULTS: Safety analyses included 705 patients: capivasertib-fulvestrant (n = 355) and placebo-fulvestrant (n = 350). Frequent any-grade AEs with capivasertib-fulvestrant were diarrhea (72.4%), rash (38.0%), and nausea (34.6%); frequent grade ≥3 AEs were rash (12.1%), diarrhea (9.3%), and hyperglycemia (2.3%). Diarrhea, rash, and hyperglycemia occurred shortly after starting capivasertib-fulvestrant [median days to onset (interquartile range) of any grade: 8 (2-22), 12 (10-15), and 15 (1-51), respectively], and were managed with supportive medications, dose reductions, interruptions, and/or discontinuation. Discontinuation rates were 2.0%, 4.5%, and 0.3%, respectively. Overall, 13.0% discontinued capivasertib due to AEs. CONCLUSIONS: Frequent AEs associated with PI3K/AKT pathway inhibition occurred early and were manageable. The low rate of treatment discontinuations suggests that, when appropriately managed, these AEs do not pose a challenge to clinical benefit.

Breast carcinoma with brain metastases: clinical analysis and immunoprofile on tissue microarrays.

BACKGROUND: Development of brain metastasis in patients with breast carcinoma correlates with poor outcome. Identification of tumor characteristics associated with breast cancer brain metastases (BCBM) could help identify patients at risk. PATIENTS AND METHODS: We studied 209 patients with BCBM. We evaluated a panel of proteins relevant to the biology of breast carcinoma on tissue microarrays of 133 primary tumors and 56 BCBM, including paired samples from 43 patients, and correlated the findings with the clinical outcome. RESULTS: The median survival after BCBM diagnosis was 19 months (95% confidence interval, 13-23 months). Patients presenting with solitary metastasis had a significantly longer median survival than those with multiple lesions (25 versus 11 months, P ≤ 0.0001). We found no significant discordance in the expression of tested markers, but identified a possible association between the expression of basal cytokeratin CK5/6 in the primary carcinoma and the development of multiple rather than solitary brain metastases. CONCLUSIONS: Expression of antigens commonly associated with breast carcinoma does not differ significantly between the primary tumor and the corresponding brain metastases. Although no specific immunoprofile identifies breast carcinomas that develop brain metastases, we observed a possible association between CK5/6 expression in the primary tumor and multiple versus solitary BCBM.