Official Title

A Multicenter, Retrospective, Observational Study to Evaluate the Safety and Effectiveness of AlloDerm Acellular Dermal Matrix (ADM) in Immediate Post-Mastectomy, Two-Stage Implant-Based Breast Reconstruction

Purpose

Primary Objective: To evaluate the occurrence of at least one major complication of breast reconstruction for a subject within 18 months after tissue expander placement (S1 Day 1) in immediate, two-stage IBBR using prepectoral or subpectoral technique, with AlloDerm compared with control. Secondary objective: To evaluate the occurrence of reconstructive failure per breast within 18 months after S1 Day 1. Exploratory Objective: The exploratory objective of this study is to evaluate the occurrence of capsular contracture per breast within 36 months after S1 Day 1.

Detailed Description

Background and Rationale: Breast cancer is the most common cancer affecting women worldwide. Two-stage implant-based breast reconstruction (IBBR) is one of the most common surgical options for restoring breast shape and contour after a mastectomy. Among IBBR options, both subpectoral and prepectoral techniques are established approaches. While the use of soft tissue support materials such as acellular dermal matrices (ADMs) has helped address limitations of both subpectoral and prepectoral techniques, their use has also been associated with potential complications, such as infection, seroma formation, and implant loss. Therefore, robust comparative data is needed to adequately evaluate the safety and effectiveness of using ADMs like AlloDerm in IBBR using subpectoral and prepectoral techniques. The purpose of this study is to collect and analyze real-world data to support the proposed use of AlloDerm in immediate, post-mastectomy (either for cancer treatment or prophylaxis), two-stage, IBBR using a prepectoral or subpectoral technique. Additionally, the data collected in this study may inform future product development and support new indications. Study Design: This is a multicenter, retrospective, observational study that involves reviewing medical records of subjects who underwent immediate, post-mastectomy, two-stage, implant-based breast reconstruction. The study will have four study groups: · Prepectoral technique: o Prepectoral AlloDerm group o Prepectoral control group, defined as subjects who undergo breast reconstruction without the use of soft tissue support materials (e.g., no ADM, no surgical mesh): Data for this group will be collected under Study H26-279. · Subpectoral technique: o Subpectoral AlloDerm group o Subpectoral control group, defined as subjects who undergo breast reconstruction without the use of soft tissue support materials (e.g., no ADM, no surgical mesh). The two stages of the reconstruction procedure are defined below: · S1 Day 1 is defined as the time when subjects undergo the first stage of breast reconstruction surgery immediately following mastectomy. At this stage, a tissue expander is implanted either with AlloDerm or without soft tissue support materials, which determines the subject’s study group. · S2 Day 1 is defined as the time when subjects undergo exchange surgery to remove the tissue expander and insert the permanent breast implant. Exchange of the tissue expander for the permanent breast implant typically occurs within 180 days (6 months) of S1 Day 1, consistent with standard temporary tissue expander device labeling. The Index Date is defined as the date of S1 Day 1. For inclusion in the study, the Index Date must occur between 01 January 2020 and 30 April 2023 (both dates inclusive). Pre-operative data, 12 months prior to or at the Index Date, will be collected to determine subject eligibility. At a minimum, eligible study subjects will be required to have data at the Index Date and at least one post-operative follow-up within 18 months (+30 days) post Index Date. If available, data will be collected at S2 Day 1, and at all post-operative follow-up within 36 months (+30 days) post Index Date. Data types collected under this study protocol will include, but are not limited to: subject demographics, breast disease history, prior procedure history, prior medication history, nicotine use, alcohol use, breast cancer diagnosis, medical history with reported medications, comorbidities, tumor-specific characteristics, cancer therapy, pregnancy, relevant laboratory results, Stage 1 and Stage 2 procedural information, safety data including Adverse Events and Serious Adverse Events, concomitant medications and device use, Investigator information, and type of medical facility.

Eligibility Criteria

Inclusion Criteria

1. Either a waiver of consent issued by the Institutional Review Board (IRB) or an Informed Consent Form (ICF) signed by the subject/ legally authorized representative (LAR) has been obtained. 2. Subject was at least 18 years of age or older at the Index Date (S1 Day 1). 3. Subject underwent unilateral or bilateral mastectomy due to cancer or prophylaxis, and underwent immediate, implant-based, two-stage breast reconstruction: a. For AlloDerm groups only: using prepectoral or subpectoral technique with AlloDerm b. For control groups only: using prepectoral or subpectoral technique without soft tissue support materials (e.g., no ADM, no surgical mesh) 4. S1 Day 1 procedure was performed between 01 January 2020 to 30 April 2023 (both dates inclusive). 5. Availability of subject data, including pre-operative demographics, clinical characteristics, intraoperative details, and post-operative outcomes at the Index Date and at least one post-operative follow-up within 18 months (± 30 days) post Index Date.

Exclusion Criteria

1. For AlloDerm groups only: Any use of soft tissue support materials other than AlloDerm during the breast reconstruction procedures. 2. For control groups only: Any use of soft tissue support materials (e.g., any ADM or surgical mesh) during the breast reconstruction procedures. 3. Subject was pregnant at S1 Day 1. 4. Subject had any disease that is clinically known to impact wound healing ability, such as uncontrolled diabetes (e.g., HbA1c >8) or history of compromised wound healing at S1 Day 1. 5. Subject had blood dyscrasia, such as neutropenia, thrombocytopenia, or anemia at S1 Day 1. 6. Subject had a documented history of known autoimmune disease or immune deficiency except for mild psoriasis or Hashimoto’s disease prior to S1 Day 1. 7. Subject had documented history of active infection (local to chest or systemic) at S1 Day 1. 8. Subject had a known coagulation disorder or was on a treatment regimen of prescribed anticoagulation/antiplatelet therapy (e.g., warfarin, clopidogrel) at S1 Day 1. Use of anticoagulation therapy for prophylaxis is acceptable. 9. Subject had a history of primary augmentation within 12 months prior to S1 Day 1. 10. Subject had any documented history of augmentation revision, reconstruction, reduction, or mastopexy on the study breast(s) prior to S1 Day 1. 11. Subject had a concomitant unrelated condition of breast/chest wall/skin (e.g., significant chest wall abnormalities including pectus excavatum or pectus carinatum) at S1 Day 1. 12. Subject received narcotics for chronic pain 10 days prior to S1 Day 1. 13. Subject had documented nicotine use 4 weeks prior to S1 Day 1. 14. Subject had any documented history of clinically significant drug or alcohol abuse at S1 Day 1. 15. Subject was on a treatment regimen of steroids or immunosuppressant drugs within 30 days prior to S1 Day 1 (e.g., azathioprine, tacrolimus, anti-thymocyte globulin, rituximab, daclizumab) with the following exceptions: one time use of prophylactic steroids administered peri-operatively, general use of inhaled steroids, topical steroids applied to non-study breast areas, and immune suppression drugs or steroids used specifically in the treatment of breast cancer (e.g., dexamethasone). 16. Subject was on a treatment regimen of aspirin 7 days prior to S1 Day 1. 17. Subject was on a treatment regimen of NSAIDs (excluding aspirin) 3 days prior to S1 Day 1. 18. Subject was treated with any investigational drug or device within 30 days or 5 half-lives of the investigational drug (whichever is longer) prior to S1 Day 1. 19. Subject received chemotherapy for indication of cancer within 3 weeks prior to S1 Day 1. 20. Subject received radiation therapy, including any pre-operative radiation therapy, to the study breast(s), prior to S1 Day 1.

Keywords and/or Specific Medical Conditions

AlloDerm

Unilateral or Bilateral Mastectomy

Implant-based breast reconstruction

Sponsors

AbbVie Inc.