Efficacy of taxanes rechallenge in first-line treatment of early metastatic relapse of patients with HER2-negative breast cancer previously treated with a (neo)adjuvant taxanes regimen: A multicentre retrospective observational study

Unmet need for previously untreated metastatic triple-negative breast cancer: a real-world study of patients diagnosed from 2011 to 2022 in the United States

BACKGROUND

This real-world study describes the treatment landscape evolution after targeted therapy approval and associated survival outcomes for previously untreated metastatic triple-negative breast cancer (mTNBC) in the United States.

PATIENTS AND METHODS

This retrospective analysis used de-identified electronic health record-derived data of patients diagnosed with mTNBC (January 2011-July 2022; index date was first-line [1L] treatment start date). Patient characteristics, treatment patterns, real-world overall survival (rwOS), and time to next treatment or death (TTNTD) were determined. Outcomes before (2011-2017, early cohort) and after (2018-2022, late cohort) targeted therapy approval were evaluated.

RESULTS

Among 2004 eligible patients, 21% were classified as Black, 13% had Eastern Cooperative Oncology Group performance status ≥2, and 63% were diagnosed with recurrent disease; median age was 60 years. First-line chemotherapy-only (single- and multiple-agent chemotherapy) use decreased with the introduction of targeted therapies from 96% before 2018 to 65% between 2019 and 2022. From 2019, 33% of patients received programmed death-(ligand) 1 inhibitor-based regimen; ~2% received poly (ADP-ribose) polymerase inhibitors. Median 1L treatment duration was 2.6 months and this did not change over time. Of all 1L patients, 34% died before second-line (2L) and 51% subsequently received 2L treatment. Median (95% CI) 1L rwOS and TTNTD were 11.3 (10.7-12.0) months and 4.3 (4.1-4.6) months, respectively. Median 1L 5-year survival [95% CI] showed statistically significant but small improvement from the early (10.9 [10.3-11.6] months) to late cohort (11.9 [10.7-13.1] months; HR [95% CI], 0.87 [0.78-0.96]).

CONCLUSION

This analysis demonstrated that, despite changes in care over time, survival improvements were not clinically meaningful; thus, a substantial unmet need for more efficacious treatments in previously untreated patients with mTNBC remains.

IMpassion132 double-blind randomised phase III trial of chemotherapy with or without atezolizumab for early relapsing unresectable locally advanced or metastatic triple-negative breast cancer

BACKGROUND

Immune checkpoint inhibitors improve the efficacy of first-line chemotherapy for patients with programmed death-ligand 1 (PD-L1)-positive unresectable locally advanced/metastatic triple-negative breast cancer (aTNBC), but randomised data in rapidly relapsing aTNBC are scarce.

PATIENTS AND METHODS

IMpassion132 (NCT03371017) enrolled patients with aTNBC relapsing <12 months after last chemotherapy dose (anthracycline and taxane required) or surgery for early TNBC. PD-L1 status was centrally assessed using SP142 before randomisation. Initially patients were enrolled irrespective of PD-L1 status. From August 2019, enrolment was restricted to PD-L1-positive (tumour immune cell ≥1%) aTNBC. Patients were randomised 1:1 to placebo or atezolizumab 1200 mg every 21 days with investigator-selected chemotherapy until disease progression or unacceptable toxicity. Stratification factors were chemotherapy regimen (carboplatin plus gemcitabine or capecitabine monotherapy), visceral (lung and/or liver) metastases and (initially) PD-L1 status. The primary endpoint was overall survival (OS), tested hierarchically in patients with PD-L1-positive tumours and then, if positive, in the modified intent-to-treat (mITT) population (all-comer patients randomised pre-August 2019). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR) and safety.

RESULTS

Among 354 patients with rapidly relapsing PD-L1-positive aTNBC, 68% had a disease-free interval of <6 months and 73% received carboplatin/gemcitabine. The OS hazard ratio was 0.93 (95% confidence interval 0.73-1.20, P = 0.59; median 11.2 months with placebo versus 12.1 months with atezolizumab). mITT and subgroup results were consistent. Median PFS was 4 months across treatment arms and populations. ORRs were 28% with placebo versus 40% with atezolizumab. Adverse events (predominantly haematological) were similar between arms and as expected with atezolizumab plus carboplatin/gemcitabine or capecitabine following recent chemotherapy exposure.

CONCLUSIONS

OS, which is dismal in patients with TNBC relapsing within <12 months, was not improved by adding atezolizumab to chemotherapy. A biology-based definition of intrinsic resistance to immunotherapy in aTNBC is urgently needed to develop novel therapies for these patients in next-generation clinical trials.

EMP2 Serves as a Functional Biomarker for Chemotherapy-Resistant Triple-Negative Breast Cancer

Breast cancer (BC) remains among the most commonly diagnosed cancers in women worldwide. Triple-negative BC (TNBC) is a subset of BC characterized by aggressive behavior, a high risk of distant recurrence, and poor overall survival rates. Chemotherapy is the backbone for treatment in patients with TNBC, but outcomes remain poor compared to other BC subtypes, in part due to the lack of recognized functional targets. In this study, the expression of the tetraspan protein epithelial membrane protein 2 (EMP2) was explored as a predictor of TNBC response to standard chemotherapy. We demonstrate that EMP2 functions as a prognostic biomarker for patients treated with taxane-based chemotherapy, with high expression at both transcriptomic and protein levels following treatment correlating with poor overall survival. Moreover, we show that targeting EMP2 in combination with docetaxel reduces tumor load in syngeneic and xenograft models of TNBC. These results provide support for the prognostic and therapeutic potential of this tetraspan protein, suggesting that anti-EMP2 therapy may be beneficial for the treatment of select chemotherapy-resistant TNBC tumors.

Efficacy of anlotinib in Chinese patients with metastatic breast cancer: A retrospective observational study

Anlotinib, a multitarget tyrosine kinase inhibitor, can inhibit tumour angiogenesis proliferation, metastasis, promote vascular normalization, increase T cell and NK cell activity and infiltration, remodel tumour microenvironment and synergistic immune enhancement. Our study aimes to evaluate the efficacy of anlotinib in the treatment of advanced metastatic breast cancer (MBC) after multiple lines of therapy. Patients included were treated with anlotinib for advanced MBC in the Affiliated Cancer Hospital of Zhengzhou University from 1 January 2019 to 30 June 2023. The objective remission rate, disease-free progression survival and adverse reactions were analysed. We compared and analysed the efficacy of anlotinib in the treatment of advanced metastatic breast cancer, which showed that ORR was 23.6% and DCR was 69.1%. The DCR of monotherapy was 66.7% and that of combination therapy was 69.6% in MBC patients. The combination therapy, combined with chemotherapy had the best effect (79.3%), combined with immunotherapy came second. In addition, the DCR (88.9%) was higher in MBC patients having received prior antiangiogenic therapy. According to the Kaplan-Meier (K-M) survival estimate analysis, the mPFS was 4.17 months (95% CI, 1.758-6.582 months) in Her-2 positive MBC patients, and 7.83 months (95% CI, 2.416-9.104) in Her-2 negative MBC patients. The mPFS was 5.76 months (95% CI, 3.231-8.298 m) in HR positive MBC patients, 7.83 months (95% CI, 3.182-12.478 m) in TNBC patients. Fatigue (20.0%), hypertension (21.8%) and liver dysfunction (18.2%) were common adverse reactions, followed by bone marrow suppression (16.4%), anorexia (14.5%), hypothyroidism (14.5%) and diarrhoea (14.5%). Altogether, Anlotinib monotherapy or combination therapy provides a viable third (or above)-line therapeutic strategy in patients with metastatic breast cancer. The adverse reactions of anlotinib are well tolerated and controllable.

Taxane rechallenge during metastatic disease in HER-2 negative breast cancer patients: Clinical activity, tolerance and survival results

BACKGROUND

Taxanes are major drugs for metastatic breast cancer (MBC) treatment, and are generally well tolerated, making them attractive for therapeutic reintroduction (rechallenge) during metastatic course. In view of the paucity of current literature, we questioned the usefulness of taxane rechallenge in a population of patients previously treated with taxanes in a metastatic setting.

METHODS

From the local database of a French cancer center, we retrospectively identified 756 patients diagnosed with ER+/HER2-, or triple negative MBC, and treated between 2008 and 2021. Among them, 58 patients (7.8%) were rechallenged with taxanes. Clinical characteristics, response rates, and survival were retrospectively evaluated and compared to patients who received taxanes only once.

RESULTS

Compared to non-rechallenged population, patients treated with taxane rechallenge were significantly younger, with better general status, and received more treatment. First taxane exposure led to better tumor response and was more frequently discontinued for reasons other than progression, compared to the non-rechallenged population. Taxane rechallenge led to an objective response rate of 27.6%, and a clinical benefit rate of 46.6%, with a median progression-free survival (PFS) of 5.7 months, and a median overall survival (OS) of 11.6 months. We also found a PFS2/PFS1 ratio >1.3 in 55.2% of the rechallenge population.

CONCLUSION

Although only a minority of MBC patients are concerned, taxane rechallenge appears to be a pragmatic option with an acceptable tolerance, and good efficacy, especially when these drugs have shown clinical activity earlier in the disease course, and/or have been stopped for reasons other than progression.