Loss-of-function mutations in
BRCA1
and
BRCA2
are detected in at least 5% of unselected patients with breast cancer (BC). These BC susceptibility genes encode proteins critical for DNA homologous ...recombination repair (HRR). This review provides an update on oral poly(ADP-ribose) polymerase (PARP) inhibitors for the treatment of BC. Olaparib and talazoparib are PARP inhibitors approved as monotherapies for deleterious/suspected deleterious germline BRCA-mutated, HER2-negative BC. Olaparib is approved in the USA for metastatic BC and in Europe for locally advanced/metastatic BC. Talazoparib is approved for locally advanced/metastatic BC in the USA and Europe. In phase 3 trials, olaparib and talazoparib monotherapies demonstrated significant progression-free survival benefits compared with chemotherapy. Common toxicities were effectively managed by supportive treatment and dose interruptions/reductions. Veliparib combined with platinum-based chemotherapy has also shown promise for locally advanced/metastatic BC in a phase 3 trial. Differences in efficacy and safety across PARP inhibitors (olaparib, talazoparib, veliparib, niraparib, rucaparib) may relate to differences in potency of PARP trapping on DNA and cytotoxic specificity. PARP inhibitors are being investigated in early BC, in novel combinations, and in patients without germline BRCA mutations, including those with somatic BRCA mutations and other HRR gene mutations. Ongoing phase 2/3 studies include PARP inhibitors combined with immune checkpoint inhibitors for the treatment of triple-negative BC. Wider access to testing for BRCA and other mutations, and to genetic counseling, are required to identify patients who could benefit from PARP inhibitor therapy. The advent of PARP inhibitors has potential benefits for BC treatment beyond the locally advanced/metastatic setting.
Among patients with triple-negative breast cancer and high expression of PD-L1, pembrolizumab plus chemotherapy resulted in longer overall survival than chemotherapy alone.
PIK3CA
mutations occur in approximately 40% of patients with hormone receptor–positive breast cancer. A PI3K inhibitor, alpelisib, combined with fulvestrant led to a median progression-free survival ...of 11 months, as compared with 5.7 months with placebo plus fulvestrant. Hyperglycemia, rash, and diarrhea were more common with alpelisib.
Among women with previously untreated hormone-receptor–positive advanced breast cancer, the addition of the cyclin-dependent kinase inhibitor palbociclib to letrozole therapy resulted in longer ...progression-free survival than that with letrozole alone.
Hormone-receptor–positive breast cancer represents the largest therapeutic subtype of the disease, accounting for 60 to 65% of all malignant neoplasms of the breast. For more than 50 years, the treatment of hormone-receptor–positive disease has been focused on targeting the estrogen-receptor signaling pathway.
1
However, both new and acquired resistance to hormonal blockade occurs in a large subset of these cancers, and new approaches are needed.
2
The cyclin-dependent kinases (CDKs) are a large family of serine–threonine kinases that play an important role in regulating cell-cycle progression. The interaction of cyclin D with CDK4 and CDK6 facilitates the hyperphosphorylation of the retinoblastoma (Rb) . . .
Blockade of colony-stimulating factor-1 (CSF-1) limits macrophage infiltration and improves response of mammary carcinomas to chemotherapy. Herein we identify interleukin (IL)-10 expression by ...macrophages as the critical mediator of this phenotype. Infiltrating macrophages were the primary source of IL-10 within tumors, and therapeutic blockade of IL-10 receptor (IL-10R) was equivalent to CSF-1 neutralization in enhancing primary tumor response to paclitaxel and carboplatin. Improved response to chemotherapy was CD8+ T cell-dependent, but IL-10 did not directly suppress CD8+ T cells or alter macrophage polarization. Instead, IL-10R blockade increased intratumoral dendritic cell expression of IL-12, which was necessary for improved outcomes. In human breast cancer, expression of IL12A and cytotoxic effector molecules were predictive of pathological complete response rates to paclitaxel.
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•Macrophages are the primary source of IL-10 in mammary carcinomas•IL-10 receptor blockade improves primary tumor response to paclitaxel•IL-10 suppresses expression of IL-12 by tumor dendritic cells during chemotherapy•IL12A expression correlates with response to chemotherapy in breast cancer patients
Ruffell et al. show that tumor-infiltrating macrophages produce IL-10, which limits cytotoxic T cell responses by suppressing the expression of IL-12 by intratumoral dendritic cell and, thus, provides a mechanism for the effect of CSF-1 blockade in breast cancer.
To provide evidence-based guidance on the clinical management of cancer cachexia in adult patients with advanced cancer.
A systematic review of the literature collected evidence regarding ...nutritional, pharmacologic, and other interventions, such as exercise, for cancer cachexia. PubMed and the Cochrane Library were searched for randomized controlled trials (RCTs) and systematic reviews of RCTs published from 1966 through October 17, 2019. ASCO convened an Expert Panel to review the evidence and formulate recommendations.
The review included 20 systematic reviews and 13 additional RCTs. Dietary counseling, with or without oral nutritional supplements, was reported to increase body weight in some trials, but evidence remains limited. Pharmacologic interventions associated with improvements in appetite and/or body weight include progesterone analogs and corticosteroids. The other evaluated interventions either had no benefit or insufficient evidence of benefit to draw conclusions on efficacy. Limitations of the evidence include high drop-out rates, consistent with advanced cancer, as well as variability across studies in outcomes of interest and methods for outcome assessment.
Dietary counseling may be offered with the goals of providing patients and caregivers with advice for the management of cachexia. Enteral feeding tubes and parenteral nutrition should not be used routinely. In the absence of more robust evidence, no specific pharmacological intervention can be recommended as the standard of care; therefore, clinicians may choose not to prescribe medications specifically for the treatment of cancer cachexia. Nonetheless, when it is decided to trial a drug to improve appetite and/or improve weight gain, currently available pharmacologic interventions that may be used include progesterone analogs and short-term (weeks) corticosteroids.
We present data from patients with advanced biliary tract cancer (BTC) receiving pembrolizumab in the KEYNOTE‐158 (NCT02628067; phase 2) and KEYNOTE‐028 (NCT02054806; phase 1b) studies. Eligible ...patients aged ≥18 years from both studies had histologically/cytologically confirmed incurable BTC that progressed after standard treatment regimen(s), measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status 0/1, and no prior immunotherapy. Programmed death ligand 1 (PD‐L1)‐positive tumors were required for eligibility in KEYNOTE‐028 only. Patients received pembrolizumab 200 mg every three weeks (KEYNOTE‐158) or 10 mg/kg every two weeks (KEYNOTE‐028) for ≤2 years. Primary efficacy endpoint was objective response rate (ORR) by RECIST v1.1. Response assessed by independent central review is reported. KEYNOTE‐158 enrolled 104 patients and KEYNOTE‐028 enrolled 24 patients. Median (range) follow‐up was 7.5 months (0.6‐34.3) in KEYNOTE‐158 and 5.7 months (0.6‐55.4) in KEYNOTE‐028. In KEYNOTE‐158, ORR was 5.8% (6/104; 95% CI, 2.1%‐12.1%); median duration of response (DOR) was not reached (NR) (range, 6.2‐26.6+ months). Median (95% CI) OS and PFS were 7.4 (5.5‐9.6) and 2.0 (1.9‐2.1) months. Among PD‐L1‐expressers (n = 61) and PD‐L1‐nonexpressers (n = 34), respectively, ORR was 6.6% (4/61) and 2.9% (1/34). In KEYNOTE‐028, ORR was 13.0% (3/23; 95% CI, 2.8%‐33.6%); median DOR was NR (range, 21.5‐53.2+ months). Median (95% CI) OS and PFS were 5.7 (3.1‐9.8) and 1.8 (1.4‐3.1) months. Grade 3 to 5 treatment‐related adverse events occurred in 13.5% of patients in KEYNOTE‐158 (no grade 4; grade 5 renal failure, n = 1) and 16.7% in KEYNOTE‐028 (no grade 4/5). In summary, pembrolizumab provides durable antitumor activity in 6% to 13% of patients with advanced BTC, regardless of PD‐L1 expression, and has manageable toxicity.
What's new?
Biliary tract cancer is usually diagnosed at a late stage and has a terrible prognosis, and few treatment options are available. Here, the authors present results from 2 clinical trials that evaluated pembrolizumab, a monoclonal antibody that binds to the programmed death 1 receptor (PD‐1) in patients with advanced BTC. Six to 13% of patients had an objective response. Among those who had a response, this was long‐lasting. All were of at least 6 months duration, with one lasting more than 4 years.
Abstract
Background
Understanding the impact of the tumor immune microenvironment and BRCA1/2-related DNA repair deficiencies on the clinical activity of immune checkpoint inhibitors may help ...optimize both patient and treatment selection in metastatic triple-negative breast cancer. In this substudy from the phase 3 IMpassion130 trial, immune biomarkers and BRCA1/2 alterations were evaluated for association with clinical benefit with atezolizumab and nab-paclitaxel (A+nP) vs placebo and nP in unresectable (P+nP) locally advanced or metastatic triple-negative breast cancer.
Methods
Patients were randomly assigned 1:1 to nab-paclitaxel 100 mg/m2 (days 1, 8, and 15 of a 28-day cycle) and atezolizumab 840 mg every 2 weeks or placebo until progression or toxicity. Progression-free survival and overall survival were evaluated based on programmed death-ligand 1 (PD-L1) expression on immune cells (IC) and tumor cells, intratumoral CD8, stromal tumor-infiltrating lymphocytes, and BRCA1/2 mutations.
Results
PD-L1 IC+ in either primary or metastatic tumor tissue was linked to progression-free survival and overall survival benefit with A+nP. PD-L1 IC+ low (26.9%; 243 of 902 patients) and high (13.9%; 125 of 902 patients) populations had improved outcomes that were comparable. Intratumoral CD8 and stromal tumor-infiltrating lymphocytes positivity (sTIL+) were associated with PD-L1 IC+ status; improved outcomes were observed with A+nP vs P+nP only in CD8+ and sTIL+ patients who were also PD-L1 IC+. BRCA1/2 mutations (occurring in 14.5% 89 of 612 patients) were not associated with PD-L1 IC status, and PD-L1 IC+ patients benefited from A+nP regardless of BRCA1/2 mutation status.
Conclusions
Although A+nP was more efficacious in patients with richer tumor immune microenvironment, clinical benefit was only observed in patients whose tumors were PD-L1 IC+.
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