Leuprorelin combined with letrozole with/without everolimus in ovarian-suppressed premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer: The LEO study

Comparison of mTOR inhibitors combined with endocrine therapy versus that alone in breast cancer: a meta-analysis

BACKGROUND

This meta-analysis aims to evaluate the efficacy and safety of rapamycin (mTOR) inhibitors with endocrine therapy versus endocrine therapy alone in treating advanced or metastatic estrogen receptor/progesterone receptor (ER/PR) + breast cancer.

METHODS

We conducted a comprehensive search in PubMed, Web of Science, Embase, and the Cochrane Library for randomized controlled trials (RCTs) comparing mTOR inhibitors plus endocrine therapy with endocrine therapy alone up to September 2024.

RESULTS

This analysis included 10 RCTs comprising 3,337 patients. Relative to endocrine therapy alone, the combination of mTOR inhibitors and endocrine therapy significantly improved the clinical benefit rate (RR = 1.41, p < 0.001), overall response rate (RR = 1.40, p = 0.006), progression-free survival (PFS; HR = 0.67, p < 0.001), and overall survival (OS; HR = 0.86, p = 0.056), although the improvement in OS was not statistically significant. Subgroup analyses indicated a more pronounced PFS advantage in patients under 65 years of age (HR = 0.55, p = 0.013) and those who had previously received chemotherapy (HR = 0.51, p = 0.001). However, the incidence of adverse events was higher in the combination therapy group, notably stomatitis (p < 0.001), elevated aspartate aminotransferase/alanine aminotransferase (p = 0.04), and diarrhea (p = 0.01).

CONCLUSIONS

The combination of mTOR inhibitors with endocrine therapy offers superior efficacy with manageable toxicities in patients with advanced or metastatic ER/PR+ breast cancer.

Self-Assembled Multivalent Aptamer Drug Conjugates: Enhanced Targeting and Cytotoxicity for HER2-Positive Gastric Cancer

Antibody drug conjugates (ADCs) have shown promise to be the mainstream chemotherapeutics for advanced HER2-positive cancers, yet the issues of poor drug delivery efficiency, limited chemotherapeutic effects, severe immune responses, and drug resistance remain to be addressed before the clinical applications of ADCs. The DNA aptamer-guided drug conjugates (ApDCs) are receiving growing attention for specific tumors due to their excellent tumor affinity and low cost. Therefore, developing a multivalent ApDC nanomedicine by combining anti-HER2 aptamer (HApt), tetrahedral framework nucleic acid (tFNA), and deruxtecan (Dxd) together to form HApt-tFNA@Dxd might help to address these concerns. In this study, the HER2-targeted DNA aptamer modified DNA tetrahedron (HApt-tFNA) was employed as a system for drug delivery, and the adoption of tFNA could effectively enlarge the drug-loading rate compared to aptamer-guided ApDCs previously reported. Compared with free Dxd and tFNA@Dxd, HApt-tFNA@Dxd showed better structural stability, excellent targeted cytotoxicity to HER2-positive gastric cancer, and increased tissue aggregation ability in tumors. These features and superiorities make HApt-tFNA@Dxd a promising chemotherapeutic medicine for HER2-positive tumors. Our work developed a new targeting nanomedicine by combining DNA nanomaterials and chemotherapeutic agents, which represents a critical advance toward developing novel DNA-based nanomaterials and promoting their potential applications for HER2-positive cancer therapy.

CDK4/6 inhibitors versus PI3K/AKT/mTOR inhibitors in women with hormone receptor-positive, HER2-negative metastatic breast cancer: An updated systematic review and network meta-analysis of 28 randomized controlled trials

Background

Updated evidence was required to compare the efficacy and safety of cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) inhibitors for patients with hormone receptor-positive and HER2-negative metastatic breast cancer.

Methods

A systematic review and network meta-analysis was conducted utilizing data from randomized controlled trials (RCTs) that contained interventions of CDK4/6 inhibitors or PI3K/AKT/mTOR inhibitors. Progression-free survival (PFS), overall survival (OS), and treatment-related adverse events (TRAEs) were primary outcomes of interest. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% credible intervals (CrIs) were used to assess the survival outcomes and safety profiles, respectively.

Results

A total of 28 RCTs with 12,129 participants were included. Pooled analysis showed that CDK4/6 inhibitors significantly prolonged PFS than PI3K/AKT/mTOR inhibitors (HR, 0.81; 95% CrI, 0.69–0.94), whereas no significant differences were detected regarding OS. After balancing the treatment lines and metastatic sites, the superiority of CDK4/6 inhibitors only appeared in the visceral and non-visceral subgroups. Among CDK4/6 inhibitors, abemaciclib was significantly better than others in ≥3 grade neutropenia (OR, 0.04; 95% CrI, 0.01–0.15). The incidence of stomatitis and digestive disorders was different among diverse kinds of PI3K/AKT/mTOR inhibitors. Discrepancies appeared regarding TRAEs of hepatotoxicity, diarrhea, and hyperglycemia among different interventions.

Conclusions

CDK4/6 inhibitors showed better efficacy in PFS, but the benefits disappeared when taking treatment line into consideration. Specific and discrepant safety profiles were found in two categories of agents.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022321172.

Preparation of Long-acting Somatostatin and GnRH Analogues and their Applications in Tumor Therapy

Hormonal drugs are essential treatment options for some hormone-dependent or hormone-sensitive tumors. The common dosage forms of hormonal drugs have a short half-life. Hence, frequent administration is needed, which results in poor patient compliance. Nevertheless, using drug delivery technology, somatostatin analogues (SSAs) and gonadotropin-releasing hormone (GnRH) analogues are prepared into long-acting formulations that can significantly prolong the action time of these drugs, reducing medication frequency and increasing patient compliance. Such drugs are advantageous when treating acromegaly, gastroenteropancreatic neuroendocrine tumors (GEP-NETs), breast cancer, prostate cancer, and other diseases having a relatively long course. SSAs and GnRH analogues are two typical hormonal drugs, the long-acting formulations of which are essential in clinical practice. This review summarized the preparation methods and clinical application of long-acting formulations in cancer. Further, the action mechanism and new research of SSAs and GnRH analogues were discussed, and suggestions related to the development of long-acting SSAs and GnRH analogues were provided.

Effectiveness of Adding Everolimus to the First-line Treatment of Advanced Breast Cancer in Premenopausal Women Who Experienced Disease Progression While Receiving Selective Estrogen Receptor Modulators: A Phase 2 Randomized Clinical Trial

Importance

The effectiveness of the mammalian target of rapamycin (mTOR) inhibitor everolimus in premenopausal women with hormone receptor (HR)-positive/ERBB2-negative advanced breast cancer who experienced disease progression while receiving selective estrogen receptor modulators (SERMs) is unknown.

Objective

To compare the effectiveness of everolimus plus letrozole vs letrozole alone in premenopausal women with HR-positive/ERBB2-negative advanced breast cancer who experienced disease progression while receiving SERMs.

Design, Setting, and Participants

The Everolimus Trial for Advanced Premenopausal Breast Cancer (MIRACLE) was a multicenter, open-label phase 2 randomized clinical trial of everolimus plus letrozole vs letrozole alone as first-line treatment conducted from December 8, 2014, to September 26, 2018. Participants included premenopausal women with HR-positive, ERBB2-negative advanced breast cancer who experienced disease progression while receiving SERMs. Analysis was performed on an intent-to-treat basis from January 5, 2015, to December 30, 2019.

Exposures

Patients were randomly assigned in a 1:1 ratio to receive everolimus (10 mg orally once daily) plus letrozole (2.5 mg orally once daily) (n = 101) or letrozole alone (2.5 mg orally once daily) (n = 98). Both groups received goserelin, 3.6 mg, subcutaneously on day 1 of each 28-day cycle. Patients in the letrozole group were permitted to cross over to receive everolimus with letrozole if disease progression occurred.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS), defined as the time from randomization to confirmed disease progression or death due to any cause.

Results

A total of 199 women (mean [SD] age, 44.3 [6.3] years) were randomized. Patients receiving everolimus plus letrozole achieved a significantly longer median PFS compared with those receiving letrozole alone (19.4 months [95% CI, 16.3-22.0 months] vs 12.9 months [95% CI, 7.6-15.7 months]; hazard ratio, 0.64 [95% CI, 0.46-0.89]; P = .008). A total of 56 of the 98 patients in the letrozole group (57.1%) were crossed over to also receive everolimus. The median PFS after crossover was 5.5 months (95% CI, 3.8-8.2 months).

Conclusions and Relevance

In this randomized clinical trial, PFS was significantly longer among premenopausal patients with HR-positive/ERBB2-negative advanced breast cancer who received everolimus plus letrozole than among those who received letrozole alone. The results revealed that everolimus was effective even among patients receiving treatment with the same endocrine agent after disease progression.

Trial Registration

ClinicalTrials.gov Identifier: NCT02313051.

Final results of the randomized phase 2 LEO trial and bone protective effects of everolimus for premenopausal hormone receptor-positive, HER2-negative metastatic breast cancer

The phase 2 LEO study showed that everolimus (EVE) plus letrozole (LET) with ovarian suppression increased progression-free survival (PFS) in tamoxifen-exposed premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer with visceral metastases. Here we report final survival outcomes from the LEO study, and the results of exploratory analyses of bone turnover marker changes and bone-specific progressive disease. Patients who were exposed to or progressed on tamoxifen as adjuvant/palliative treatments were randomly assigned (2:1) to the EVE (leuprorelin + LET + EVE, n = 92) or LET (leuprorelin + LET, n = 45) arm. In a median 51-months of follow-up, the median PFS was 17.5 and 13.8 months in the EVE and LET arms, respectively (P = .245). Patients in the EVE arm with baseline visceral (median PFS 16.4 vs 9.5 months, P = .040) and bone (median PFS 17.1 vs 10.9, P = .003) metastases had greater PFS compared to the LET arm. No differences in overall survival (OS) were observed (median OS, 48.3 vs 50.8 months, P = .948). The 1-year cumulative incidences of bone-specific disease progression were 6.0% and 23.4% in the EVE and LET arms, respectively (hazard ratio 0.26, P < .001). Bone turnover markers at 6 and 12 weeks after treatment decreased in the EVE arm but were increased or stationary in the LET arm. Skeletal-related events occurred in 6.5% and 11.1% of patients in the EVE and LET arms, respectively. EVE + LET with ovarian suppression prolonged PFS in patients with baseline visceral or bone metastases and offered bone-protective effects in the overall study population. However, these clinical benefits did not translate into an OS benefit.