The anti-PD-L1/CTLA-4 bispecific antibody KN046 in combination with nab-paclitaxel in first-line treatment of metastatic triple-negative breast cancer: a multicenter phase II trial.

This multicenter, phase II study (NCT03872791) aims to evaluate the efficacy and safety of the anti-PD-L1/CTLA-4 bispecific antibody KN046 combined with nab-paclitaxel in the first-line treatment of patients with metastatic triple-negative breast cancer (TNBC). The primary endpoints included objective response rate (ORR) and duration of response (DoR), and secondary endpoints included progression-free survival (PFS), overall survival (OS) rate, safety, and the correlation of PD-L1 status with clinical efficacy. This trial met pre-specified endpoints. 27 female patients were enrolled sequentially to receive KN046 in two dose levels (3 mg/kg or 5 mg/kg). Among the 25 evaluable patients, the ORR achieved 44.0% (95% CI, 24.4% - 65.1%), and the median DoR was not mature. The median PFS reached 7.33 months (95%CI, 3.68 - 11.07 months), and the median OS was 30.92 months (95%CI, 14.75 - NE months). In PD-L1 positive patients, PFS was 8.61 months (versus 4.73 months) and the 2-year OS rate was 62.5% (versus 57.1%) compared to PD-L1 negative patients. Patients tolerated well the combination therapy. In general, KN046 combined with nab-paclitaxel showed favorable efficacy and survival benefits with tolerable toxicity in the first-line treatment of metastatic TNBC, especially PD-L1 positive, which is worth further investigation.

Toripalimab plus nab-paclitaxel in metastatic or recurrent triple-negative breast cancer: a randomized phase 3 trial.

The combination of immune-checkpoint blockade with chemotherapy for the first-line treatment of advanced triple-negative breast cancer (TNBC) has generated mixed results. TORCHLIGHT is a randomized, double-blinded phase 3 trial evaluating the efficacy and safety of first-line toripalimab and nab-paclitaxel (nab-P) (n = 353; experimental arm) versus placebo and nab-P (n = 178; control arm) for the treatment of women with metastatic or recurrent TNBC. The primary end point was progression-free survival (PFS) assessed by a blinded independent central review in the PD-L1-positive and intention-to-treat populations. The secondary end points included overall survival and safety. Overall, 200 and 100 patients, in the toripalimab and placebo arm respectively had PD-L1-positive TNBC. At the prespecified interim analysis, a statistically significant improvement in PFS assessed by a blinded independent central review was demonstrated in the experimental arm in the PD-L1-positive population (median PFS 8.4 versus 5.6 months; hazard ratio (HR) = 0.65, 95% confidence interval (CI) 0.470-0.906, P = 0.0102). The median overall survival was 32.8 versus 19.5 months (HR = 0.62, 95% CI 0.414-0.914, P = 0.0148). Similar incidences of treatment-emergent adverse events (AEs) (99.2% versus 98.9%), grade ≥3 treatment-emergent AEs (56.4% versus 54.3%) and fatal AEs (0.6% versus 3.4%) occurred in the experimental and control arms. The addition of toripalimab to nab-P provided a significant improvement in PFS for PD-L1-positive patients with metastatic or recurrent TNBC with an acceptable safety profile. ClinicalTrial.gov identifier NCT03777579 .

HS-10352 in hormone receptor-positive, HER2-negative advanced breast cancer: A phase 1 dose-escalation trial.

BACKGROUND: Approximately 40% of patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) exhibit PIK3CA mutations. AIMS: This study aims to evaluate the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of HS-10352, a selective PI3Kα inhibitor, in this patient population. MATERIALS AND METHODS: Conducted as a phase 1 dose-escalation trial, HS-10352 was administered orally once-daily (QD) at dose levels of 2, 4, 6, and 8 mg. The primary endpoints were dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD). This study is registered at ClinicalTrials.gov (NCT04631835). RESULTS: Between August 2020 and March 2022, a total of 18 female patients were enrolled. DLT, manifested as hyperglycemia, occurred in two patients in the 8 mg QD group, establishing an MTD of 6 mg QD. The most common treatment-related adverse events were hyperglycemia (88.9%) and weight loss (61.3%). In the 6 mg QD group, four patients (66.7%) had a partial response (PR), and one (16.7%) had stable disease (SD). Among the four patients with PIK3CA mutated tumors in this dosage group, three (75.0%) had PR and one (25.0%) had SD. The median progression-free survival was not reached (95% confidence interval, 11.1-NA). DISCUSSION AND CONCLUSION: HS-10352 at 6 mg QD was well-tolerated in patients with HR-positive, HER2-negative ABC, and showed preliminary antitumor activity in patients with PIK3CA mutated tumors. These findings support the further clinical development of HS-10352.

Predictive biomarkers of response and survival following immunotherapy with a PD-L1 inhibitor benmelstobart (TQB2450) and antiangiogenic therapy with a VEGFR inhibitor anlotinib for pretreated advanced triple negative breast cancer.

In our phase Ib trial (ClinialTrials.gov Identifier: NCT03855358), benmelstobart (TQB2450), a novel humanized IgG1 antibody against PD-L1, plus antiangiogenic multikinase inhibitor, anlotinib, demonstrated promising antitumor activities in pretreated triple negative breast cancer (TNBC) patients. We conducted explorative analyses of genomic biomarkers to explore the associations with treatment response and survival outcomes. Targeted next generation sequencing (NGS) was undertaken toward circulating tumor DNA (ctDNA) collected from peripheral blood samples prior to the start of treatment and after disease progression. A total of 31 patients received targeted NGS and functional driver mutations in 29 patients were analyzed. The most frequent mutations were TP53 (72%), MLL3 (28%), and PIK3CA (17%). At a blood-based tumor mutational burden (bTMB) cutoff of 6.7 mutations per megabase, patients with low bTMB showed better response to anlotinib plus TQB2450 (50% vs. 7%, P = 0.015) and gained greater PFS benefits (7.3 vs. 4.1 months, P = 0.012) than those with high bTMB. At a maximum somatic allele frequency (MSAF) cutoff of 10%, a low MSAF indicated a better objective response (43% vs. 20%) as well as a significantly longer median PFS (7.9 vs. 2.7 months, P < 0.001). Patients with both low MSAF and low bTMB showed a notably better objective response to anlotinib plus TQB2450 (70% vs. 11%, P < 0.001) and a significantly longer median PFS (11.0 vs. 2.9 months, P < 0.001) than patients with other scenarios. Our findings support future studes and validation of MSAF and the combined bTMB-MSAF classification as predictive biomarkers of immune checkpoint inhibitor-based regimens in advanced TNBC patients.

Exploring the clinical outcomes and safety profile of inetetamab treatment in metastatic breast cancer patients: A multicenter assessment of a Chinese-origin recombinant Anti-HER2 monoclonal antibody.

BACKGROUND: Inetetamab is a novel recombinant humanized anti-HER2 monoclonal antibody. This study aimed to evaluate the efficacy and safety of inetetamab and predictive factors for response in HER2-positive metastatic breast cancer (MBC) patients. METHODS: A cohort of HER2-positive MBC patients who received inetetamab-based therapy between June 2020 and August 2021 was evaluated. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR) and disease control rate (DCR). Adverse events (AEs) were graded according to the National Cancer Institute Common Toxicity Criteria. RESULTS: A total of 141 patients were included in the final analysis. The median PFS of the entire cohort was 7.1 months. The median number of treatment lines administered was three. The ORR was 36.9 %, and the DCR was 80.9 %. The most frequently employed treatment strategy was inetetamab + chemotherapy (49/141, 34.8 %), followed by inetetamab + HER2-tyrosine kinase inhibitors (HER2-TKIs) + chemotherapy, inetetamab + pertuzumab + chemotherapy, inetetamab + endocrine treatment and inetetamab + HER2-TKIs. Cox multivariate analysis revealed that PFS was associated with liver metastasis (hazard ratio [HR] 2.112, 95 % confidence interval [CI] 1.334-3.343, p = 0.001), previous HER2-TKI treatment (HR 2.019, 95 % CI 1.133-3.597, p = 0.017) and estrogen receptor positivity (HR 0.587, 95 % CI 0.370-0.934, p = 0.024). The toxicity was tolerable, with neutropenia being the most common treatment-related grade 3/4 AE (14.9 %). CONCLUSION: Inetetamab demonstrates effectiveness with a manageable safety profile, offering a promising therapeutic option for HER2-positive breast cancer patients who have shown resistance to prior anti-HER2 treatments.

Catalase-like pleated niobium carbide MXene loaded with polythiophene for oxygenated sonodynamic therapy in solid tumor.

Sonodynamic therapy (SDT), an emerging treatment for solid tumors, has the advantages of deep tissue penetration, non-invasiveness, low side effects, and negligible drug resistance. However, the hypoxic environment of deep solid tumors can discount the efficacy of oxygenated dependent SDT. Here, we synthesized a polythiophene-based sonosensitizer (PT2) and a two-dimensional pleated niobium carbide (Nb2C) Mxene. PT2 was loaded onto the surface of poly(vinylpyrrolidone) (PVP)-coated Nb2C MXene through electrostatic interaction to obtain Nb2C-PVP-PT2 nanosheets (NSs) with a high loading efficiency of 153.7%. Nb2C MXene exhibited catalase-like activity, which could catalyze hydrogen peroxide (H2O2) to produce O2, in turn alleviating tumor hypoxia and enhancing the efficacy of SDT. The depletion of H2O2 further results in abnormal cellular H2O2 levels and reduced tumor cell activity. Moreover, the decomposed NSs led to the release of the sonosensitizer PT2 that can efficiently generate both singlet oxygen and superoxide anions under ultrasound irradiation. These events led to the inhibition of DNA replication of tumor cells, causing tumor cell death, allowing for enhanced SDT efficacy.

Pyrotinib versus placebo in combination with trastuzumab and docetaxel as first line treatment in patients with HER2 positive metastatic breast cancer (PHILA): randomised, double blind, multicentre, phase 3 trial.

OBJECTIVE: To assess the efficacy and safety of pyrotinib (an irreversible pan-HER (human epidermal growth factor receptor) inhibitor), trastuzumab, and docetaxel compared with placebo, trastuzumab, and docetaxel for untreated HER2 positive metastatic breast cancer. DESIGN: Randomised, double blind, placebo controlled, multicentre, phase 3 trial. SETTING: 40 centres in China between 6 May 2019 and 17 January 2022. PARTICIPANTS: 590 female patients (median age 52 (interquartile range 46-58) years) with untreated HER2 positive metastatic breast cancer. INTERVENTIONS: Eligible patients were randomised 1:1 to receive either oral pyrotinib (400 mg once daily) or placebo, both combined with intravenous trastuzumab (8 mg/kg in cycle 1 and 6 mg/kg in subsequent cycles) and docetaxel (75 mg/m2) on day 1 of each 21 day cycle. Randomisation was stratified by treatment history of trastuzumab in the (neo)adjuvant setting and hormone receptor status. Patients, investigators, and the sponsor's study team were masked to treatment assignment. MAIN OUTCOME MEASURES: The primary endpoint was progression-free survival as assessed by the investigator. RESULTS: Of the 590 randomised patients, 297 received pyrotinib, trastuzumab, and docetaxel treatment (pyrotinib group), and 293 received placebo, trastuzumab, and docetaxel treatment (placebo group). At data cut-off on 25 May 2022, the median follow-up was 15.5 months. The median progression-free survival according to the investigator was significantly longer in the pyrotinib group than in the placebo group (24.3 (95% confidence interval 19.1 to 33.0) months versus 10.4 (9.3 to 12.3) months; hazard ratio 0.41 (95% confidence interval 0.32 to 0.53); one sided P<0.001). Treatment related adverse events of grade 3 or higher were reported in 267 (90%) of the 297 patients in the pyrotinib group and 224 (76%) of the 293 patients in the placebo group. No treatment related deaths occurred in the pyrotinib group, and one (<1%; diabetic hyperosmolar coma) treatment related death occurred in the placebo group. Survival and toxicities are still under assessment with longer follow-up. CONCLUSIONS: Pyrotinib, trastuzumab, and docetaxel showed superiority by significantly improving progression-free survival compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2 positive metastatic breast cancer. The toxicity was manageable. The findings support this dual anti-HER2 regimen as an alternative first line treatment option in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT03863223.

Real-world treatment patterns and outcomes of pyrotinib-based therapy in patients with HER2-positive advanced breast cancer (PRETTY): A nationwide, prospective, observational study.

Pyrotinib, an irreversible pan-ErbB inhibitor, has been approved for treating HER2-positive advanced breast cancer in China. We conducted a nationwide, prospective observational study to examine the real-world data of pyrotinib-based therapy in this population. Patients from 61 sites across China were included. Pyrotinib-based regimens were prescribed at local physician's discretion. Demographics, treatment patterns, prognosis and safety were evaluated. The primary outcome was real-world progression-free survival (rwPFS). Of 1129 patients, pyrotinib-based therapy was prescribed as first-, second- and third- or later-line treatment in 437 (38.7%), 476 (42.2%) and 216 (19.1%) patients, respectively. Median rwPFS (mrwPFS) was 14.3 (95% CI, 13.3-15.2) months in the total population, with the longest mrwPFS of 17.8 (95% CI, 15.2-24.9) months in the first-line setting, followed by 14.4 (95% CI, 12.9-15.3) months in the second-line setting. Patients with third- or later-line treatment also achieved a mrwPFS of 9.3 (95% CI, 8.4-11.8) months. Patients with trastuzumab- or trastuzumab-pertuzumab-treated disease achieved a mrwPFS of 14.3 and 13.6 months, respectively. Dual HER2 blockade with pyrotinib plus trastuzumab showed a mrwPFS of 16.2 months in the total population, with data not mature in the first-line setting. For patients with baseline brain metastases, the mrwPFS was 11.7 months. The most common adverse event was diarrhea (any grade, 73.5%; grade ≥ 3, 15.3%). In real world, pyrotinib-based therapy shows promising effectiveness in the first-, as well as second- and later-line treatment, with acceptable tolerability. Further investigations regarding front-line use or novel combinations of pyrotinib might facilitate to maximize its anti-tumor potential.

Pyrotinib plus capecitabine for trastuzumab-resistant, HER2-positive advanced breast cancer (PICTURE): a single-arm, multicenter phase 2 trial.

BACKGROUND: Patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer and primary resistance to trastuzumab have a poor clinical outcome and lack good evidence to inform clinical decision. This study investigated the efficacy and safety of pyrotinib plus capecitabine in this population. METHODS: This phase 2 trial was conducted at 16 sites in China. Patients received oral pyrotinib 400 mg once daily and capecitabine 1000 mg/m2 twice a day on days 1-14 of each 21-day cycle until disease progression or intolerable toxicity. The primary endpoint was investigator-assessed progression-free survival (PFS). RESULTS: Between June 2019 and September 2021, 100 patients were enrolled with a median age of 51 years (range, 24-69). All patients had been treated with trastuzumab and 21 (21.0%) patients had prior use of pertuzumab. As of August 31, 2022, the median follow-up duration was 20.1 months (range, 1.3-38.2). The median PFS was 11.8 months (95% confidence interval [CI], 8.4-15.1), which crossed the pre-specified efficacy boundary of 8.0 months. The objective response rate was 70.0% (70/100), with a median duration of response of 13.8 months (95% CI, 10.2-19.3). The disease control rate was 87.0% (87/100). The median overall survival was not reached. The most common grade ≥ 3 treatment-emergent adverse event was diarrhea (24 [24.0%]). No treatment-related deaths occurred. CONCLUSIONS: Pyrotinib plus capecitabine can be considered to be a treatment option in HER2-positive advanced breast cancer patients who have shown primary resistance to trastuzumab. Even in the era of modern anti-HER2 treatments, this clinical setting warrants more investigations to meet unmet needs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04001621. Retrospectively registered on June 28, 2019.

A phase Ib study of TQB2450 plus anlotinib in patients with advanced triple-negative breast cancer.

This study explored the safety and preliminary efficacy of the anti-PD-L1 antibody TQB2450 combined with the multi-kinase inhibitor anlotinib in advanced triple-negative breast cancer (TNBC). Patients with advanced TNBC who received at least one line of systemic therapy with anthracyclines and/or taxanes were enrolled in the dose-escalation and dose-expansion cohorts. Between May 29, 2019 and September 28, 2020, 34 patients were enrolled (three in the dose-escalation cohort and 31 in the dose-expansion cohort). The ORR was 26.5% (95% CI, 12.9-44.4) and the DCR was 73.5% (95% CI, 55.6-87.1). The median PFS was 5.6 (95% CI, 2.9-7.5) months, and the median OS was not reached. Seventeen (50.0%) patients had grade ≥3 treatment-related adverse events, with the most common being QT interval prolongation (17.6%) and hypertension (14.7%). No treatment-related deaths occurred. TQB2450 combined with anlotinib as a chemotherapy-free treatment shows promising efficacy with a manageable safety profile for patients with previously treated advanced TNBC.

Pyrotinib in combination with letrozole for hormone receptor-positive, human epidermal growth factor receptor 2-positive metastatic breast cancer (PLEHERM): a multicenter, single-arm, phase II trial.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) targeted therapy combined with endocrine therapy has been recommended as an alternative treatment strategy for patients with hormone receptor (HR)-positive, HER2-positive metastatic breast cancer (MBC). This study aimed to evaluate the role of pyrotinib, an oral pan-HER irreversible tyrosine kinase inhibitor, in combination with letrozole for patients with HR-positive, HER2-positive MBC. METHODS: In this multi-center, phase II trial, HR-positive and HER2-positive MBC patients who were not previously treated for metastasis disease were enrolled. Patients received daily oral pyrotinib 400 mg and letrozole 2.5 mg until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was the clinical benefit rate (CBR) assessed by an investigator according to the Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: From November 2019 to December 2021, 53 patients were enrolled and received pyrotinib plus letrozole. As of August 2022, the median follow-up duration was 11.6 months (95% confidence interval [CI], 8.7-14.0 months). The CBR was 71.7% (95% CI, 57.7-83.2%), and the objective response rate was 64.2% (95% CI, 49.8-76.9%). The median progression-free survival was 13.7 months (95% CI, 10.7-18.7 months). The most common treatment-related adverse event of grade 3 or higher was diarrhea (18.9%). No treatment-related deaths were reported, and one patient experienced treatment discontinuation due to adverse event. CONCLUSIONS: Our preliminary results suggested that pyrotinib plus letrozole is feasible for the first-line treatment of patients with HR-positive and HER2-positive MBC, with manageable toxicities. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04407988.

Dalpiciclib plus letrozole or anastrozole versus placebo plus letrozole or anastrozole as first-line treatment in patients with hormone receptor-positive, HER2-negative advanced breast cancer (DAWNA-2): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Adding CDK4/6 inhibitor dalpiciclib to fulvestrant significantly prolonged progression-free survival in patients with hormone receptor-positive, HER2-negative advanced breast cancer progressing after endocrine therapy. We aimed to assess the efficacy and safety of dalpiciclib plus letrozole or anastrozole in patients with hormone receptor-positive, HER2-negative advanced breast cancer who had no previous systemic therapy in the advanced setting. METHODS: DAWNA-2 is a randomised, double-blind, placebo-controlled, phase 3 trial done at 42 hospitals in China. Eligible patients were aged 18-75 years, of any menopausal status, had an ECOG performance status of 0-1, and had pathologically confirmed hormone receptor-positive, HER2-negative untreated advanced breast cancer. Patients were randomly assigned (2:1) to receive oral dalpiciclib (150 mg per day for 3 weeks, followed by 1 week off) or matching placebo. Both groups also received endocrine therapy: either 2·5 mg letrozole or 1 mg anastrozole orally once daily continuously. Randomisation was using an interactive web response system (block size of six) and stratified according to visceral metastasis, previous endocrine therapy in the adjuvant or neoadjuvant setting, and endocrine therapy partner. All investigators, patients, and the funders of the study were masked to group allocation. We present the results of the preplanned interim analyses for the primary endpoint of investigator-assessed progression-free survival, which was assessed in all randomly assigned patients who met the eligibility criteria by intention-to treat. Safety was analysed in all randomly assigned patients who received at least one dose of study treatment. The superiority boundary was calculated as a one-sided p value of 0·0076 or less. This trial is registered with ClinicalTrials.gov, NCT03966898, and is ongoing but closed to recruitment. FINDINGS: Between July 19, 2019, and Dec 25, 2020, 580 patients were screened and 456 were eligible and randomly assigned to the dalpiciclib group (n=303) or placebo group (n=153). At data cutoff (June 1, 2022), median follow-up was 21·6 months (IQR 18·3-25·9), and 103 (34%) of 303 patients in the dalpiciclib group and 83 (54%) of 153 patients in the placebo group had disease progression or died. Median progression-free survival was significantly longer in the dalpiciclib group than in the placebo group (30·6 months [95% CI 30·6-not reached] vs 18·2 months [16·5-22·5]; stratified hazard ratio 0·51 [95% CI 0·38-0·69]; one-sided log-rank p<0·0001). Adverse events of grade 3 or 4 were reported in 271 (90%) of 302 patients in the dalpiciclib group and 18 (12%) of 153 patients in the placebo group. The most common adverse events of grade 3 or 4 were neutropenia (259 [86%] in the dalpiciclib group vs none in the placebo group) and leukopenia (201 [67%] vs none). Serious adverse events were reported for 36 (12%) patients in the dalpiciclib group and ten (7%) patients in the placebo group. Two treatment-related deaths occurred, both in the dalpiciclib group (deaths from unknown causes). INTERPRETATION: Our findings suggest that dalpiciclib plus letrozole or anastrozole could be a novel standard first-line treatment for patients with hormone receptor-positive, HER2-negative advanced breast cancer, and is an alternative option to the current treatment landscape. FUNDING: Jiangsu Hengrui Pharmaceuticals and Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Entinostat, a class I selective histone deacetylase inhibitor, plus exemestane for Chinese patients with hormone receptor-positive advanced breast cancer: A multicenter, randomized, double-blind, placebo-controlled, phase 3 trial.

Entinostat plus exemestane in hormone receptor-positive (HR+) advanced breast cancer (ABC) previously showed encouraging outcomes. This multicenter phase 3 trial evaluated the efficacy and safety of entinostat plus exemestane in Chinese patients with HR + ABC that relapsed/progressed after ≥1 endocrine therapy. Patients were randomized (2:1) to oral exemestane 25 mg/day plus entinostat (n = 235) or placebo (n = 119) 5 mg/week in 28-day cycles. The primary endpoint was the independent radiographic committee (IRC)-assessed progression-free survival (PFS). The median age was 52 (range, 28-75) years and 222 (62.7%) patients were postmenopausal. CDK4/6 inhibitors and fulvestrant were previously used in 23 (6.5%) and 92 (26.0%) patients, respectively. The baseline characteristics were comparable between the entinostat and placebo groups. The median PFS was 6.32 (95% CI, 5.30-9.11) and 3.72 (95% CI, 1.91-5.49) months in the entinostat and placebo groups (HR, 0.76; 95% CI, 0.58-0.98; P = 0.046), respectively. Grade ≥3 adverse events (AEs) occurred in 154 (65.5%) patients in the entinostat group versus 23 (19.3%) in the placebo group, and the most common grade ≥3 treatment-related AEs were neutropenia [103 (43.8%)], thrombocytopenia [20 (8.5%)], and leucopenia [15 (6.4%)]. Entinostat plus exemestane significantly improved PFS compared with exemestane, with generally manageable toxicities in HR + ABC (ClinicalTrials.gov #NCT03538171).

Clinical efficacy of fulvestrant versus exemestane as first-line therapies for Chinese postmenopausal oestrogen-receptor positive /human epidermal growth factor receptor 2 -advanced breast cancer (FRIEND study).

AIM: To compare the efficacies of exemestane and fulvestrant as first-line monotherapies for postmenopausal Chinese women having advanced oestrogen-receptor positive (ER+)/ human epidermal growth factor receptor 2 (HER2)-breast cancer (ER+/HER2- ABC) after a previous treatment for ≥2 years with an adjuvant non-steroidal aromatase inhibitor. METHODS: In this randomised, open-label, multi-centre, parallel-controlled phase 2 FRIEND study, 145 postmenopausal ER+/HER2- ABC patients were assigned into fulvestrant (500 mg on days 0, 14 and 28, and then at every 28 ± 3 days, n = 77) and exemestane (25 mg/day, n = 67) groups. The primary outcome was progression-free survival (PFS), while the secondary outcomes were disease control rate, objective response rate, time to treatment failure, duration of response and overall survival. Exploratory end-points included gene mutation-related outcomes and safety. RESULTS: Fulvestrant was superior to exemestane regarding median PFS times (8.5 versus 5.6 months, p = 0.014, HR = 0.62, 95% confidence intervals: 0.42-0.91), objective response rates (19.5% versus 6.0%, p = 0.017) and time to treatment failure (8.4 versus 5.5 months, p = 0.008). The incidence of adverse or serious adverse events in the two groups was virtually identical. The most frequent mutations in 129 analysed patients were detected in the oestrogen receptor gene 1 (ESR1) (18/14.0%), PIK3CA (40/31.0%) and TP53 (29/22.5%) genes. Fulvestrant produced significant longer PFS times compared to exemestane but only for patients with an ESR1-wild type (8.5 versus 5.8 months) (p = 0.035), although there was a similar trend also for the ESR1 mutation without statistical significance. All patients with c-MYC and BRCA2 mutations had longer PFS times in the fulvestrant versus the exemestane group (p = 0.049, p = 0.039). CONCLUSION: Fulvestrant significantly increased overall PFS for ER+/HER2- ABC patients and was well tolerated. CLINICALTRIALS: NCT02646735, https://clinicaltrials.gov/ct2/show/NCT02646735.

Molecular subtypes predict the preferential site of distant metastasis in advanced breast cancer: a nationwide retrospective study.

Objective: This study aimed to explore possible associations between molecular subtypes and site of distant metastasis in advanced breast cancer (ABC). Methods: 3577 ABC patients were selected from 21 hospitals of seven geographic regions in China from 2012-2014. A questionnaire was designed to collect medical information regarding demographic characteristics, risk factors, molecular subtype, recurrence/metastasis information, and disease-free survival (DFS). The cancers were classified into Luminal A, Luminal B, HER2-enriched and Triple Negative subtypes. Chi-square test and multivariate Cox proportional hazard models were performed to explore the associations between molecular subtypes and distant metastasis sites. Results: A total of 2393 cases with molecular subtypes information were finally examined. Patients with Luminal A (51.1%) and Luminal B (44.7%) were most prone to bone metastasis, whereas liver metastasis was more frequently observed in HER2-enriched ABC patients (29.1%).The cumulative recurrence and metastasis rates of ABC patients at 36 months of DFS were the most significant within molecular types, of which Triple Negative was the highest (82.7%), while that of Luminal A was the lowest (58.4%). In the adjusted Cox regression analysis, Luminal B, HER2-enriched and Triple Negative subtypes increased the risk of visceral metastasis by 23%, 46% and 87% respectively. In addition, Triple Negative patients had a higher probability of brain metastasis (HR 3.07, 95% CI: 1.04-9.07). Conclusion: Molecular subtypes can predict the preferential sites of distant metastasis, emphasizing that these associations were of great help in choices for surveillance, developing appropriate screening and cancer management strategies for follow-up and personalized therapy in ABC patients.

Pamiparib in patients with locally advanced or metastatic HER2-negative breast cancer with germline BRCA mutations: a phase II study.

PURPOSE: To evaluate the efficacy and safety of pamiparib in patients with locally advanced or metastatic human epidermal growth factor receptor 2-negative (HER2-) breast cancer, with deleterious or suspected deleterious germline BRCA1/2 mutations (gBRCA1/2 m). METHODS: In this open-label, phase II, multicenter study in China (NCT03575065), patients with triple-negative breast cancer (TNBC cohort) or hormone receptor-positive (HR+)/HER2- breast cancer (HR+/HER2- cohort) and ≤ 2 prior lines of chemotherapy received pamiparib 60 mg orally twice daily in 28-day, continuous cycles. The primary endpoint was objective response rate (ORR; RECIST v1.1) by independent review committee. RESULTS: In total, 88 patients were enrolled (TNBC cohort: 62; HR+/HER2- cohort: 26). Median age was 45.5 (range: 27-67) years, and 60 patients (68.2%) had received 1 or 2 prior lines of chemotherapy; 42 patients (47.7%) had previously received platinum chemotherapy. In the TNBC cohort, ORR was 38.2% (95% confidence interval [CI] 25.4-52.3) and median duration of response (DoR) was 7.0 months (95% CI 3.9-not estimable). In the HR+/HER2- cohort, ORR was 61.9% (95% CI 38.4-81.9) and median DoR was 7.5 months (95% CI 5.6-14.8). The most common treatment-emergent adverse events (TEAEs), treatment-related TEAEs, and ≥ Grade 3 TEAEs were hematologic (including anemia, decreased neutrophil count, and decreased white blood cell count). Overall, 64.8% of patients had TEAEs leading to dose reduction and 2.3% had TEAEs leading to treatment discontinuation. CONCLUSION: Pamiparib showed encouraging efficacy and an acceptable safety profile in patients with locally advanced and metastatic HER2- breast cancer with gBRCA1/2 m. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03575065; July 2, 2018.

Tucidinostat plus exemestane for postmenopausal patients with advanced, hormone receptor-positive breast cancer: a long-term safety and overall survival update from the randomised, double-blind, placebo-controlled, phase 3 trial.

Background: The ACE study previously demonstrated that tucidinostat (chidamide), a subtype-selective histone deacetylase (HDAC) inhibitor, plus exemestane significantly improved progression-free survival (PFS) in advanced hormone receptor-positive (HR+) breast cancer patients with a manageable safety profile. The analysis of long-term safety and overall survival (OS) is presented here. Methods: ACE is a randomized, double-blind, placebo-controlled, phase 3 trial comparing tucidinostat 30 mg/twice weekly plus exemestane 25 mg/day versus placebo plus exemestane 25 mg/day in postmenopausal patients with advanced, HR+ breast cancer. The primary endpoint was PFS, and OS was the secondary endpoint. Results: Of the 365 patients enrolled between July 2015, and June 2017, 244 were assigned to tucidinostat plus exemestane (tucidinostat group) and 121 to placebo plus exemestane group (placebo group). Baseline characteristics were well balanced between groups. The median follow-up from randomization to data cut-off (February 25, 2021) of this analysis was 26.5 months (range, 13.9-45.5 months). A total of 231 deaths (63.3%) from 365 patients occurred, including 155 deaths (63.5%) in the tucidinostat group and 76 deaths (62.8%) in the placebo group. The median OS was 30.3 months (95% CI, 26.7-36.7) in the tucidinostat group and 30.3 months (95% CI, 24.8-38.1) in the placebo group. The safety profiles of both tucidinostat and placebo groups remained consistent with those previously reported, and no new safety signals were observed with longer follow-up. Neutropenia of grade 3 or 4 occurred in 51.6% of the patients in the tucidinostat group and 2.5% of the patients in the placebo group. Adverse events (AEs) that led to treatment discontinuations from any cause occurred in 28 (11.5%) patients in the tucidinostat group and 4 (3.3%) in the placebo group. Conclusions: Although tucidinostat in combination with exemestane had produced a clinically meaningful and statistically significant improvement in the primary endpoint PFS, the ACE study did not show a prolongation of the secondary endpoint OS in the tucidinostat combination regimen. Ongoing studies have been considered in terms of potential identification of what patient subpopulations could benefit most from the tucidinostat combination regimens in advanced HR+ breast cancer.

Efficacy and safety of abemaciclib-based therapy versus tucidinostat-based therapy after progression on palbociclib in patients with HR+HER2- metastatic breast cancer.

Background: For patients with hormone receptor-positive HER2-negeative metastatic breast cancer (HR+HER2- MBC), switching to another cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) or targeted drugs with different mechanism are considerable treatment strategies post-CDK4/6i. However, no clinical data has been reported on which of the two strategies is more effective. In order to explore optimal treatment option post-CDK4/6i, we performed a retrospective comparative cohort study to evaluate the efficacy and safety of abemaciclib-based therapy versus tucidinostat-based therapy after progression on palbociclib. Methods: We identified patients with HR+HER2- MBC who had received abemaciclib-based therapy or tucidinostat-based therapy after progression on palbociclib from the database of Chinese Society of Clinical Oncology Breast Cancer (CSCO BC). Baseline characteristics, efficacy and safety information of treatments were derived from seven research centers' medical records. The primary endpoint was progression-free survival (PFS), the secondary endpoints were clinical benefit rate (CBR), PFS according to PIK3CA gene type, and safety. Results: Between April 1st 2020 and June 30th 2022, a total of 149 patients were included, of whom 73 patients received abemaciclib plus endocrine therapy (ET), and 76 patients received tucidinostat plus ET. The majority of patients had visceral disease (124/149, 83.2%) and ≥3 metastatic organs (76/149, 51.0%), one third (48/149, 32.2%) had previously been treated ≥3 lines of ET at baseline in MBC setting. CBR was 38.4% (28/73) in abemaciclib group and 17.1% (13/76) in tucidinostat group (P=0.004). There was significant difference in PFS between abemaciclib group and tucidinostat group in both the whole population (5.0 vs. 2.0 months; hazard ratio =0.44; 95% CI: 0.31-0.64; P<0.001) and propensity score matched population. PIK3CA mutations occurred in 44.20% of patients who had undergone multigene sequencing. PIK3CA-mutant showed a negative effect on PFS of abemaciclib-based therapy. Neutropenia was the most common adverse event in both groups for any grade and grades 3-4. Common non-hematological toxicity occurred in abemaciclib group was diarrhea (27.4%), and were increased aspartate aminotransferase (AST) (26.3%), nausea (25.0%), vomiting (11.8%) and hypokalemia (13.2%) in tucidinostat group. Conclusions: Our study suggests superiority of abemaciclib-based therapy over tucidinostat-based therapy in patients progressed on palbociclib, which merits further assessment in larger and prospective trials.

Circulating tumor DNA profile and its clinical significance in patients with hormone receptor-positive and HER2-negative mBC.

Background: After early-line (first- and second-line) endocrine therapy, hormone-receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancers (mBCs) become resistant to endocrine therapy. Genetic alterations may underlie resistance to endocrine therapies. This study aims to investigate the circulating tumor DNA (ctDNA) alterations and the clinical implication in hormone-receptor-positive, HER2-negative metastatic breast cancer patients with multiline endocrine therapy failure. Methods: This registered study (NCT05079074, ClinicalTrials.gov) enrolled 104 patients with hormone-receptor-positive, HER2-negative metastatic breast cancer who progressed after the early-line endocrine therapy. ctDNA alterations were analyzed by next generation sequencing (NGS). ctDNA alterations were ranked and clustered by using R 'ComplexHeatmap' and 'hclust' function. ctDNA-guided therapy was administrated. Progression-free survival (PFS) was assessed COX regression analysis, and Kaplan-Meier curves were plotted. Findings: The top ctDNA altered genes were TP53 (39%), PIK3CA (38%), BRCA1/2 (13%), ESR1 (12%), FGFR (11%), ERBB2 (11%), and GATA3 (9%). Among these genes, TP53, PIK3CA helix domain mutation (PIK3CA-HD), FGFR, ESR1 and GATA3 were related to endocrine therapy resistance. The genetic landscapes changed and tumor mutation burden increased in both TP53-altered and PIK3CA-altered patients. Both BRCA1/2 and ERBB2 alterations correlated with TP53 alterations (P=0.02 and P=0.04, respectively). However, while 93% BRCA1/2 alterations concentrated in PIK3CA-wildtype patients, 82% ERBB2 alterations concentrated in PIK3CA-altered patients. Kaplan-Meier curves showed that patients who received druggable ctDNA alteration-guided treatment (DDAT) had significantly longer PFS than those who received physician-chosen therapy, with median PFS of 6.1 months versus 4.6 months (hazard ratio = 0.53, 95% CI: 0.34-0.85, Logrank P = 0.006). Conclusion: Multiple genetic alterations were important reasons for the failure of endocrine therapy for HR-positive and HER2-negative mBC. Targeting these genes might restore the treatment sensitivity and benefit survival.

A prospective, open-label, multicenter phase IV clinical trial on the safety and efficacy of lobaplatin-based chemotherapy in advanced breast cancer.

Background: Since lobaplatin (LBP) has been approved to treat metastatic breast cancer in China, this study aimed to evaluate the safety and efficacy of LBP-based chemotherapy in clinical practice. Methods: This trial was a prospective, open-label, multicenter phase IV clinical trial that enrolled patients with unresectable locally advanced or recurrent/metastatic breast cancer from 34 sites between July 2013 and March 2017. Patients were treated with LBP monotherapy or in combination for four to six cycles. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR). Results: A total of 1179 patients were analyzed; 59 (5.0%) were treated with LBP alone, 134 (11.4%) with LBP plus paclitaxel, 263 (22.3%) with LBP plus docetaxel, 237 (20.1%) with LBP plus gemcitabine, 403 (34.2%) with LBP plus vinorelbine, and 83 (7.0%) with other LBP-based regimens. The overall incidence of adverse events (AEs) was 95.2%, and 57.9% of patients had grade >3 AEs. The most common grade >3 AEs were neutropenia (43.9%), leukopenia (39.4%), anemia (17.8%), and thrombopenia (17.7%). LBP monotherapy showed the lowest incidence of grade >3 AEs (39.0%), followed by LBP plus docetaxel (52.9%), LBP plus paclitaxel (59.0%), LBP plus vinorelbine (62.5%), and LBP plus gemcitabine (62.9%). The ORR and DCR were 36.8 and 77.0%, respectively. The median PFS was 5.5 months (95% confidence interval: 5.2-5.9). Conclusion: LBP-based chemotherapy shows favorable efficacy in patients with advanced breast cancer, with manageable safety profile. Trial registration: This trial was registered with ChiCTR.org.cn, ChiCTR-ONC-13003471.