Omental Tissue Autograft in Human Recurrent Glioblastoma Multiforme (rGBM)

Laparoscopically harvested omental grafts are commonly used to fill surgical cavities after resection of head and neck cancers. Investigators hypothesize that an omental tissue graft implanted into our patients with resected recurrent GBM may be used as a readily available and accessible means of circumventing the blood brain barrier (BBB) selectively and focally. The laparoscopically harvested omental graft omentum would easily conform to many resected GBM cavities in our human patients with acceptable risk. The predictable and rich vascular anatomy of a laparoscopically harvested piece of omentum makes it an ideal tissue for cases of previously irradiated and/or infected wound beds. This is why it is successfully used in head and neck and skull base tumors. The permeability of the new blood vessels formed between the omental graft and the cortical brain surface should allow for improved delivery of chemotherapeutics and immune cells (macrophages and T cells) into the vicinity, extracellular space and microenvironment of the resected tumor cavity including the brain adjacent to the tumor (BAT). Milky spots within the greater omentum are very small white-coloured areas of lymphoid tissue will also provide direct deposition of immune cells such as dendritic, macrophages and lymphocytes into the milieu of the resected GBM. The milky spots are made up of mesenchymal cells and are covered in a layer of mesothelium. These structures surround the small blood vessels. The enclosing mesothelium contains macrophages, lymphocytes and mast cells. They are also known as secondary lymphoid organs. Most milky spots contain extremely thin-walled lymphatic capillaries. In addition, the technique of fat grafting has been reliably used since 1990 as a way to improve and enhance wound healing, scar healing, as well as tissue augmentation and tissue repair following radiation injury.

All subjects included in the study will undergo standard surgical resection for diagnosed recurrent GBM. Following the resection, the surgical cavity will be lined with a laparoscopically harvested piece of autologous omentum. The patient's dura, bone and scalp will be closed as is customary. The subject will be followed for side effects within 72 hours, 7 days, 30 days, 60 days, 120 days and 180 days. Risk assessment will include seizure, stroke, infection, tumor progression, and death.

The investigators aim to prove that this commonly surgical technique for head and neck cancers and reconstructive surgery is safe in a small human cohort of patients with resected recurrent GBM and may improve progression-free survival (PFS) and overall survival (OS).

Inclusion criteria

• Subject is a male or female 18 years of age or older.
• Subject is undergoing planned resection of known or suspected GBM.
• Subject has a Karnofsky Performance Status (KPS) 70% or greater.
• Subject has a life expectancy of at least 6 months, in the opinion of the Investigator.
• Based on the pre-operative evaluation by neurosurgeon, the subject is a candidate for ≥ 80% resection of enhancing region.
• Subject must be able to undergo MRI evaluation.
• Subject meets the following laboratory criteria:

• White blood count ≥ 3,000/μL
• Absolute neutrophil count ≥ 1,500/μL
• Platelets ≥ 100,000/μL
• Hemoglobin > 10.0 g/dL (transfusion and/or ESA allowed)
• Total bilirubin and alkaline phosphatase ≤ 2x institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) < 3 x ULN
• Blood urea nitrogen (BUN) and creatinine < 1.5 x ULN
• Females of reproductive potential must have a negative serum pregnancy test and be willing to use an acceptable method of birth control.
• Able to understand and willing to sign an institutional review board (IRB)- approved written informed consent document

Inclusion criteria

considered during surgery:

• Subject has a histologically confirmed (frozen section) diagnosis of recurrent WHO Grade IV glioblastoma multiforme (GBM).
• Omental graft is technically feasible.

Exclusion criteria

• Subject, if female, is pregnant or is breast feeding.
• Subject intends to participate in another clinical trial.
• Subject intends to undergo treatment with the Gliadel® wafer at the time of this surgery.
• Subject has an active infection requiring treatment.
• Subject has radiographic evidence of multi-focal disease or leptomeningeal dissemination.
• Subject has a history of other malignancy, unless the patient has been disease- free for at least 5 years. Adequately treated basal cell carcinoma or squamous cell skin cancer is acceptable regardless of time, as well as localized prostate carcinoma or cervical carcinoma in situ after curative treatment
• Subject has a known positive test for human immunodeficiency virus infection, or active hepatitis B or hepatitis C infection.
• Subject has a history or evidence of any other clinically significant disorder, condition or disease that would pose a risk to subject safety or interfere with the study evaluation, procedures or completion.
• Subject has had prior abdominal surgery that in the opinion of the general surgeon makes removal of omentum more risky or inadequate.
• Subject has severe renal insufficiency rendering gadolinium MRI contraindicated.
• Subject who are unable to have an MRI scan for any reason.