Epidemiology, Outcomes, and Complement Gene Variants in Secondary Thrombotic Microangiopathies

BACKGROUND

The identification of complement defects as major drivers of primary atypical hemolytic uremic syndrome (HUS) has transformed the landscape of thrombotic microangiopathies (TMAs), leading to the development of targeted therapies and better patient outcomes. By contrast, little is known about the presentation, genetics, and outcomes of TMA associated with specific diseases or conditions, also referred to as secondary TMA.

METHODS

In this study, we assessed the relative incidence, clinical and genetic spectra, and long-term outcomes of secondary TMA versus other TMAs in consecutive patients hospitalized with a first episode of TMA from 2009 to 2019 at two European reference centers.

RESULTS

During the study period, 336 patients were hospitalized with a first episode of TMA. Etiologies included atypical HUS in 49 patients (15%), thrombotic thrombocytopenic purpura (TTP) in 29 (9%), shigatoxin-associated HUS in 70 (21%), and secondary TMA in 188 (56%). The main causes of secondary TMA were hematopoietic stem-cell transplantation ( n =56, 30%), solid-organ transplantation ( n =44, 23%), and malignant hypertension ( n =25, 13%). Rare variants in complement genes were identified in 32 of 49 patients (65%) with atypical HUS and eight of 64 patients (13%) with secondary TMA; pathogenic or likely pathogenic variants were found in 24 of 49 (49%) and two of 64 (3%) of them, respectively ( P < 0.001). After a median follow-up of 1157 days, death or kidney failure occurred in 14 (29%), eight (28%), five (7%), and 121 (64%) patients with atypical HUS, TTP, shigatoxin-associated HUS, and secondary TMA, respectively. Unadjusted and adjusted Cox regressions showed that patients with secondary TMA had the highest risk of death or kidney failure (unadjusted hazard ratio [HR], 3.35; 95% confidence interval [CI], 1.85 to 6.07; P < 0.001; adjusted HR, 4.11; 95% CI, 2.00 to 8.46; P < 0.001; considering atypical HUS as reference).

CONCLUSIONS

Secondary TMAs represent the main cause of TMA and are independently associated with a high risk of death and progression to kidney failure.

Abstract OT1-04-01: AMEERA-6: Phase 3 Study of Adjuvant Amcenestrant Versus Tamoxifen for Patients With Hormone Receptor-Positive Early Breast Cancer, Who Have Discontinued Adjuvant Aromatase Inhibitor Therapy Due to Treatment-related Toxicity

Background: About 30% of patients (pts) with hormone receptor (HR)-positive early breast cancer (EBC) on adjuvant aromatase inhibitor (AI) therapy discontinue due to toxicity with 22% of pts discontinuing during the first year (Henry et al. JCO 2012). For these patients who struggle with adjuvant AIs, there are limited alternatives including switch to a different AI which may have similar side effects, tamoxifen, or observation. This paucity of effective and tolerable options may contribute to poor adherence and/or early discontinuation of adjuvant endocrine therapy, which is associated with worse outcomes. Amcenestrant (SAR439859) is an optimized oral selective estrogen receptor degrader (SERD) with potent dual activity which antagonizes and degrades the estrogen receptor (ER), resulting in inhibition of the ER signaling pathway. In the phase 1/2 AMEERA-1 first-in-human trial (SABCS 2020 PD8-08), amcenestrant showed strong antitumor activity and favorable safety profile in the treatment of HR+ metastatic breast cancer. The phase 2 window-of-opportunity study AMEERA-4 evaluating two doses of amcenestrant demonstrated robust Ki67 reductions, strong engagement of the ER target, and continued to show a favorable safety profile in an early breast cancer population. Based on pharmacodynamic activity, safety, and emerging results from other ongoing amcenestrant trials, the 200 mg daily dose of amcenestrant was selected for the AMEERA-6 study. Trial Design: This is a prospective, randomized, international, double-blind, double-dummy, phase 3 superiority study of amcenestrant versus tamoxifen. Eligible pts are men and women with any menopausal status with HR+ stage IIB/III breast cancer, irrespective of human epidermal growth factor receptor 2 (HER2) status. If neoadjuvant systemic therapy was administered, pts must have residual nodal disease after definitive breast surgery (ypN1-3). Pts will be centrally assessed to have ER-positive and/or progesterone receptor-positive (≥10% positive stained cells) status by immunohistochemistry assay. Pts must have received at least 6 months of adjuvant AIs (≥3 months in the adjuvant setting if they received prior neoadjuvant AI) and discontinued within 30 months of initiation due to AI-related toxicity. Pts may have been treated with more than one AI. All adjuvant therapies including chemotherapy, anti-HER2 treatment, cyclin-dependent kinase (CDK) 4/6 inhibitor, and/or poly (ADP-ribose) polymerase (PARP) inhibitors must be completed or stopped prior to randomization. 3738 pts will be randomized 1:1 to receive either amcenestrant 200 mg daily or tamoxifen 20 mg daily for 5 years and will be followed for 10 years from randomization. Men and pre/peri-menopausal women will also receive a GnRH analog. Extended adjuvant endocrine therapy upon completion of study treatment is allowed per investigator discretion. Stratification factors include duration of prior AI therapy, HER2 status and prior chemotherapy, prior CDK4/6 inhibitors, geographic region, and menopausal status. The primary endpoint is invasive breast cancer-free survival (IBCFS) based on STEEP criteria version 2.0 defined as occurrence of first recurrence of the disease: ipsilateral or regional invasive, distant recurrence, contralateral invasive breast cancer and death. Key secondary endpoint is invasive disease-free survival (IDFS) and other secondary endpoints include overall survival, safety, patient reported outcomes, and pharmacokinetics of amcenestrant. Adherence to treatment and biomarkers are exploratory endpoints. AMEERA-6 recruited the first patient in March 2022 and is being conducted in partnership with AFT, BIG, EORTC, and Sanofi. Clinical trial information: NCT05128773

Citation Format: Otto Metzger, Christina Herold, Coralie Poncet, Heidi De Swert, Jose Casas-Martin, Ann Partridge, Samia Guita, Lisa Carey, Eva Schumacher, Theodora Goulioti, Thomas Meyskens, Joseph Gannon, Khadija Benlhassan, Giovanna Rossi, Eleni Xenophontos, Amal Arahmani, Amylou C. Dueck, Gautier Paux, Etienne Brain, David A. Cameron. AMEERA-6: Phase 3 Study of Adjuvant Amcenestrant Versus Tamoxifen for Patients With Hormone Receptor-Positive Early Breast Cancer, Who Have Discontinued Adjuvant Aromatase Inhibitor Therapy Due to Treatment-related Toxicity [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT1-04-01.

Long term outcome data from the EORTC 75111-10114 ETF/BCG randomized phase II study: Pertuzumab and trastuzumab with or without metronomic chemotherapy for older patients with HER2-positive metastatic breast cancer, followed by T-DM1 after progression

INTRODUCTION

Older patients are at higher risk of chemotherapy-induced toxicity, raising interest in less toxic anti-HER2 regimens for older persons with HER2-positive (HER2+) metastatic breast cancer (MBC).

PATIENTS AND METHODS

This phase II study randomized (1:1) patients with HER2+ MBC, aged 70+ or frail 60+, to first line chemotherapy with metronomic oral cyclophosphamide (M) + Trastuzumab (T) and Pertuzumab (P) or TP alone. T-DM1 was offered in case of progression.

RESULTS

In total, 39 and 41 patients were randomized to TP and TPM arm respectively. Median follow-up is 54.0 months. 24-month PFS was 18.7% (95% CI 8.2-32.4) and 28.7% (95% CI 15.8-43.0), respectively. A total of 49 (61.3%) patients died of whom 37 (75.5%) from disease progression; number of deaths per arm was 27 (69.2%) for TP and 22 (53.7%) for TPM. There was no significant difference in OS between the two arms (median OS TP vs TPM: 32.1 vs 37.5 months, p 0.25). Among the 40 patients who have started T-DM1 after disease progression on TP/TPM, PFS rate at 6 months after start of T-DM1 was 43.6% (95% CI: 27.7-58.5) and grade 3 or higher AE occurred in 18 pts (45%).

CONCLUSIONS

Metronomic chemotherapy-based dual blockade (TPM), followed by T-DM1 after progression, provides an active and relatively well tolerated treatment option in an older/frail HER2+ MBC population, with a median survival of over 3 years. Nevertheless, the majority of this older/frail population died from breast cancer, highlighting the need for well tolerated and efficacious treatments in these patients.

Adjuvant study of amcenestrant (SAR439859) versus tamoxifen for patients with hormone receptor-positive (HR+) early breast cancer (EBC), who have discontinued adjuvant aromatase inhibitor therapy due to treatment-related toxicity (AMEERA-6)

TPS607

Background: There are currently limited treatment options for patients with HR+ EBC who have discontinued adjuvant treatment with aromatase inhibitors (AIs) due to treatment-related toxicity. Amcenestrant is an optimized oral selective estrogen receptor degrader (SERD) with potent dual activity which antagonizes and degrades the ER resulting in inhibition of the ER signalling pathway. Preliminary clinical evidence from the phase 1/2 AMEERA-1 trial has demonstrated meaningful antitumour activity and a favourable safety profile of amcenestrant in the treatment of HR+ advanced breast cancer (Linden HM, Campone M, Bardia A, et al: Abstract PD8-08: A phase 1/2 study of SAR439859, an oral selective estrogen receptor (ER) degrader (SERD), as monotherapy and in combination with other anti-cancer therapies in postmenopausal women with ER-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC): AMEERA-1. SABCS 2020 PD8-08). Methods: AMEERA-6 is a prospective, randomized, international, double-blind, double-dummy, phase 3 study. 3738 patients will be randomized 1:1 to receive either amcenestrant 200 mg daily or tamoxifen 20 mg daily. Eligible patients are pre-or postmenopausal women or men with HR+ EBC (stage IIB-III) who have received at least 6 months of adjuvant AIs (at least 3 months in the adjuvant setting if they have received prior neoadjuvant AI therapy) and discontinued them within 30 months of initiation due to treatment-related toxicity. Participants will be centrally assessed to have ER+ and/or PgR+ (≥10% positive stained cells) status by immunohistochemistry assay. Prior use of adjuvant CDK4/6 inhibitors are allowed. Patients are eligible irrespective of HER2 status; for patients with HER2-positive disease adjuvant anti-HER2 treatment and chemotherapy must be completed prior to randomization. Stratification factors include: duration of AI therapy, HER2 status, prior chemotherapy, prior CDK4/6 inhibitors, geographic region, and menopausal status. Planned treatment duration is 5 years. Patients will be followed-up for 10 years from randomization. The primary endpoint is invasive breast cancer-free survival (IBCFS). Invasive disease-free survival is a key secondary endpoint, while other secondary endpoints include distant relapse-free survival (RFS), locoregional RFS, overall survival, breast-cancer specific survival, safety, patient reported outcomes and pharmacokinetics. Adherence to treatment is an exploratory endpoint. AMEERA-6 opened for recruitment in January 2022. Clinical trial information: NCT05128773.

Cancer surveillance in adults with germline TP53 pathogenic variants: A single-center observational study

10530

Background: Germline pathogenic variants (PV) in the tumor suppressor gene TP53 are associated with a high risk of developing diverse malignancies, often at young age, and predispose to Li-Fraumeni syndrome (LFS). Surveillance programs for presymptomatic PV carriers have shown survival benefit in a non-randomized trial. Here we describe the surveillance findings and clinical outcomes of adults with TP53 PV undergoing a standardized screening protocol. Methods: We identified adults with germline PV in TP53 who underwent surveillance at the University Hospitals Leuven, Belgium, between 04/2013 and 08/2020. Patients with prior cancer were allowed, while patients with an active malignancy requiring treatment at diagnosis of the TP53 PV were excluded. Surveillance was performed per modified Toronto protocol, including annual whole body diffusion-weighted MRI (WB-DWI/MRI), brain MRI, abdominal ultrasound (US), endoscopic surveillance, laboratory tests, dermatological examination and breast MRI/US in females. The primary aim was to evaluate the number and type of malignancies and premalignant lesions diagnosed during screening and to assess the proportion of malignancies detected by surveillance. Secondary outcomes were the cancer detection rate during the first year of screening, the proportion of carriers with false-positive findings, and overall survival. Results: We included 42 adults from 20 apparently unrelated families. Median age was 38y (range, 17-70y) and 23 had a history of prior cancer. After a median follow-up of 41.5mo, we diagnosed 18 cancers in 12/42 participants (29%). Overall survival was 95% in all participants, including 2 carriers who opted to discontinue surveillance. Surveillance detected 10/18 cancers (56%), the majority of whom through WB-DWI/MRI (6/10; 60%). No malignancies were identified with brain MRI. In 5/42 individuals (12%), surveillance detected a malignancy during the first year of screening. Only 2/10 cancers discovered with surveillance (1 soft tissue and 1 bone sarcoma) belong to the LFS core tumors. Cancers not detected with surveillance (8/18) were 6 non-melanoma skin cancers and 2 interval cancers (sarcoma post radiation, secondary acute leukemia). Additionally, we detected 27 premalignant lesions in 11/42 patients (26%), of whom 78% were diagnosed by colonoscopy. False-positive findings occurred in 7/42 patients (17%) and were mostly seen with WB-DWI/MRI. Conclusions: Adults with germline PV in TP53 that undergo surveillance have high cancer detection rates. The majority of malignancies were asymptomatic at diagnosis and detected with WB-DWI/MRI. Despite the high cancer incidence, few LFS core cancers were diagnosed and survival was encouraging. Increased genetic testing changes the clinical picture of germline TP53 carrier populations, justifying the transition from LFS to a wider concept of heritable TP53-related cancer syndrome.

Retrospective Analysis of the Clinical Presentation, Treatment and Outcome of Angiosarcoma in a Sarcoma Referral Center

INTRODUCTION

Angiosarcoma (AS) is a rare subtype of soft tissue sarcoma. We performed a retrospective analysis of patient characteristics, treatments and prognostic factors in patients treated in a single sarcoma center.

METHODS

We reviewed records of patients treated between 1987 and 2018, categorized in 7 different subtypes according to tissue of origin and underlying risk factors. The Kaplan-Meier method was used to estimate overall survival (OS); the Cox proportional hazards model was used to study prognostic variables.

RESULTS

Among 134 patients, 30% had radiation-induced, 31% primary soft tissue, 24% cutaneous, 5% breast, 4% bone, 2% lymphedema-associated and 4% unknown primary AS. Key patient/disease characteristics varied between subgroups. The median OS was 22.0 months for the entire cohort, with 28.9% with a 5-year survival. Metastasis at diagnosis was seen in 23% of patients; 38% developed metachronous metastasis. Sixty-six (49%) patients received systemic therapy; common first-line treatments were doxorubicin (48%) and paclitaxel (39%), without a significant difference in OS between agents. Younger age, breast/radiation-induced AS, primary surgery and palliative chemotherapy were associated with better OS. Synchronous metastasis, soft tissue/unknown primary location correlated with poor survival.

CONCLUSION

AS is a very heterogeneous sarcoma subtype, with substantial variability in clinical presentation and survival among patient subsets. Prognosis is poor, and there is no difference in outcome comparing the 2 most frequently used chemotherapy agents in the first line, paclitaxel and doxorubicin.