FDA专家组支持MarginProbe用于检测乳腺癌

马里兰州盖瑟斯堡(EGMN)—— 一种新型射频探针有望很快进入手术室以帮助外科医生确保手术切缘为良性。

在6月21日召开的会议上，美国食品药品管理局(FDA)医疗器械顾问委员会普外科与整形外科器械专家组以10:1的投票结果赞同MarginProbe系统利大于弊，支持将其作为识别已确诊乳腺癌患者原发灶切除后体外切除标本切缘癌性组织的辅助诊断工具。

专家组成员之一、美国德克萨斯大学达拉斯西南医学中心的肿瘤外科医生A. Marilyn Leitch博士说：“我认为该系统有助于降低患者接受二次手术的风险。申请方已经证明了该产品能检测出手术切缘的癌性组织。”

该系统采用电磁波实时检测人体组织的特征，在术中为外科医生提供有关切除样本是否恶性的信息。提交MarginProbe上市申请的Dune Medical Devices公司在一份书面声明中称，该产品适用于切除后20分钟内新鲜切除组织的检测。这种探针是基于介电质光谱学原理来检测组织特征。

传感器会形成射频电磁场，分层检测传感器周围数毫米深、直径7mm范围内的组织。共振特征取决于组织的特征，研究表明恶性组织所表现出来的特征有别于良性组织。

申请方在书面声明中称，该系统适合术中使用，应与术中影像学检查和触诊等其他标准方法相结合，以增加患者术中接受术腔内再切除的几率。再切除部位以标本的切缘为准，距离切缘切除表面和乳腺癌原发灶不应超过1 mm。

Dune Medical Devices公司基于多项临床试验和目的性使用试验的数据向FDA提出了上市前申请。这些试验主要在以色列开展，也有部分在美国开展。

随后，FDA委托医疗器械顾问委员会普外科与整形外科器械专家组就以下3个问题进行投票表决：

• 是否有充分的理由确保MarginProbe系统可以安全用于那些符合适应证标准的患者？

•是否有充分的理由确保MarginProbe可以有效用于那些符合适应证标准的患者？

• MarginProbe用于那些符合适应证标准的患者是否利大于弊？

11名专家组成员投票支持该产品的安全性，1票弃权。8名成员投票支持该产品用于所申请的适应证是有效的；1票反对，2票弃权。

FDA还就所提交的主要试验的终点是否合理、器械的敏感性/特异性、标本体积对未来美容术的影响、试验数据集(主要来自以色列患者)是否适用于美国人群、对申请方将开展的批准后试验的建议等问题征求了专家组的意见。

虽然没有明确规定，但FDA通常都会采纳其顾问专家组的建议。

爱思唯尔  版权所有

BY KERRI WACHTER
Elsevier Global Medical News
Breaking News

GAITHERSBURG, MARYLAND (EGMN) – A novel radiofrequency probe is one step closer to the operating room to help surgeons ensure that lumpectomy margins are benign.

At a meeting on June 21, the U.S. Food and Drug Administration’s General and Plastic Surgery Devices Panel of the Medical Devices Advisory Committee voted 10-1 that the benefits of the MarginProbe system outweigh risks when used as an adjunctive diagnostic tool for the identification of cancerous tissue at the margins of the ex vivo lumpectomy specimen following primary excision in women previously diagnosed with breast cancer.

“I think that it has the potential to be beneficial to women to reduce their chances of going back to the operating room,” said panel member Dr. A. Marilyn Leitch, an oncologic surgeon at the University of Texas Southwestern Medical Center in Dallas. “The sponsor has demonstrated that the device can detect tumor in the margins.”

The system uses electromagnetic waves to characterize human tissue in real time, providing surgeons with intraoperative information on the malignancy of the margins of an ex vivo lumpectomy specimen. It is intended for use on freshly excised tissue within 20 minutes of excision. The probe is designed to characterize tissue, based on the principles of dielectric spectroscopy, according to a written statement by the company that sponsors the MarginProbe system, Dune Medical Devices Inc.

The sensor generates radiofrequency electromagnetic fields and measures a slice of tissue 7 mm in diameter, a few mm deep and adjacent to the sensor. The resonance characteristics are dependent on tissue properties – malignant tissue has been shown to have different characteristics compared with benign tissue.

The system is intended for intraoperative use in conjunction with standard methods, such as intraoperative imaging and palpation, to increase the likelihood that patients will undergo intraoperative re-excision of the lumpectomy cavity. The locations of re-excision will correspond to the margins of the ex vivo specimen that have less than 1-mm separation of the excision surface of the margin and the primary breast cancer, according to a statement by the company.

Dune Medical Devices is seeking premarket approval of the device based on data from several clinical trials and intended-use trials conducted primarily in Israel but also in the United States.

The FDA asked the General and Plastic Surgery Devices Panel of the Medical Devices Advisory Committee to vote on three questions:

• Is there reasonable assurance that the MarginProbe system is safe for use in patients who meet the criteria specified in the proposed indication?

• Is there reasonable assurance that the MarginProbe is effective for use in for patients who meet the criteria specified in the proposed indication?

• Do the benefits of the MarginProbe for use in patients who meet the specified criteria outweigh the risks for use in this patient populations?

Eleven panel members voted that the device is safe; there was one abstention. Eight panel members voted that the device was effective with regard to the proposed indication; one member voted no and there were two abstentions.

The agency also posed a number of questions to the panel regarding the adequacy of end points of key trials submitted; device sensitivity/specificity; the effect of specimen volume on future cosmesis; the appropriateness of applying the design dataset (based primarily on Israeli patients) to a U.S. population; and suggestions for the sponsor’s proposed postapproval study.

The FDA usually follows the recommendations of its advisory panels, which are not binding.