Globus Lucidus: A porcine study of an intracranial implant designed to deliver closed, repetitive photodynamic and photochemical therapy in glioblastoma

OBJECTIVE

Herein we describe initial results in a porcine model of a fully implantable device designed to allow closed, repetitive photodynamic treatment of glioblastoma (GBM).

METHODS

This implant, Globus Lucidus, is a transparent quartz glass sphere with light-emitting diodes releasing wavelengths of 630 nm (19.5 mW/cm2), 405 nm (5.0 mW/cm2) or 275 nm (0.9 mW/cm2). 5-aminolevulinic acid was the photosensitizing prodrug chosen for use with Globus Lucidus, hence the implants illuminated at 630 nm or 405 nm. An additional 275 nm wavelength-emittance was included to explore the effects of photochemical therapy (PCT) by ultraviolet (UV) light. Twenty healthy domestic pigs underwent right-frontal craniotomies. The Globus Lucidus device was inserted into a surgically created right-frontal lobe cavity. After postoperative recovery, irradiation for up to 30 min daily for up to 14 d, or continuous irradiation for up to 14.6 h was conducted.

RESULTS

Surgery, implants, and repeated irradiations using the different wavelengths were generally well tolerated. Social behavior, wound healing, body weight, and temperature remained unaffected. Histopathological analyses revealed consistent leukocyte infiltration around the intracerebral implant sites with no significant differences between experimental and control groups.

CONCLUSION

This Globus Lucidus porcine study prepares the groundwork for adjuvant, long-term, repeated PDT of the GBM infiltration zone. This is the first report of a fully implantable PDT/PCT device for the potential treatment of GBM. A preclinical effectivity study of Globus Lucidus PDT/PCT is warranted and in advanced stages of planning.

In Vitro and Clinical Compassionate Use Experiences with the Drug-Repurposing Approach CUSP9v3 in Glioblastoma

Background: Glioblastoma represents the most common primary brain tumor in adults. Despite technological advances, patients with this disease typically die within 1–2 years after diagnosis. In the search for novel therapeutics, drug repurposing has emerged as an alternative to traditional drug development pipelines, potentially facilitating and expediting the transition from drug discovery to clinical application. In a drug repurposing effort, the original CUSP9 and its derivatives CUSP9* and CUSP9v3 were developed as combinations of nine non-oncological drugs combined with metronomic low-dose temozolomide. Methods: In this work, we performed pre-clinical testing of CUSP9v3 in different established, primary cultured and stem-like glioblastoma models. In addition, eight patients with heavily pre-treated recurrent glioblastoma received the CUSP9v3 regime on a compassionate use basis in a last-ditch effort. Results: CUSP9v3 had profound antiproliferative and pro-apoptotic effects across all tested glioblastoma models. Moreover, the cells’ migratory capacity and ability to form tumor spheres was drastically reduced. In vitro, additional treatment with temozolomide did not significantly enhance the antineoplastic activity of CUSP9v3. CUSP9v3 was well-tolerated with the most frequent grade 3 or 4 adverse events being increased hepatic enzyme levels. Conclusions: CUSP9v3 displays a strong anti-proliferative and anti-migratory activity in vitro and seems to be safe to apply to patients. These data have prompted further investigation of CUSP9v3 in a phase Ib/IIa clinical trial (NCT02770378).

CTNI-04. RECURRENT GLIOBLASTOMA LONG-TERM SURVIVORS TREATED WITH CUSP9v3

CUSP9v3 is a new treatment regimen for glioblastoma. It consists of continuous daily use of 9 drugs repurposed from general medicine. Their primary non-oncology uses are given in parentheses: aprepitant (nausea), auranofin (rheumatoid arthritis), celecoxib (pain), captopril (hypertension), disulfiram (alcohol abuse), itraconazole (fungal infection), minocycline (bacterial infection), ritonavir (viral infection) and sertraline (depression). All drugs have preclinical or clinical data indicating that they can retard glioblastoma growth, as reviewed in the published background papers. In CUSP9v3 all 9 medicines are given daily with added metronomic, low-dose (20 mg/m2 BSA twice daily) temozolomide. After 3 years of daily, uninterrupted use of CUSP9v3, of an initial cohort of 10 recurrent glioblastoma patients, as of May 2021, 3 are alive, functioning well, progression-free at 44, 44, and 57 months after recurrence and CUSP9v3 started. We report now that there were no unexpected toxicities from this combination of 10 daily drugs, although all patients required dose reduction of one or more of the drugs. CUSP9v3 was reasonably well-tolerated. Ritonavir, temozolomide, captopril and itraconazole were the drugs most frequently requiring dose reduction or pausing. The most common adverse events were nausea, headache, fatigue, diarrhea and ataxia. There were no treatment-related deaths. In the 3 long-term survivors, the median neutrophil-to-lymphocyte ratio decreased from 2.5 to 1.5 during CUSP9v3 treatment. In the group of the 3 shortest-term survivors that ratio increased from 4.7 to 14.3. CUSP9v3 follows the injunction of Palmer et al. that cancer therapy can be constructed using drug combinations that are independently effective, with non-overlapping mechanisms of action, and non-overlapping resistance pathways. We interpret the data accrued over the last few decades on the ever-shifting spatial and temporal growth drives active at any given moment in glioblastoma as requiring a complex pharmacological approach like CUSP9v3.

A phase Ib/IIa trial of 9 repurposed drugs combined with temozolomide for the treatment of recurrent glioblastoma: CUSP9v3

Background

The dismal prognosis of glioblastoma (GBM) may be related to the ability of GBM cells to develop mechanisms of treatment resistance. We designed a protocol called Coordinated Undermining of Survival Paths combining 9 repurposed non-oncological drugs with metronomic temozolomide—version 3—(CUSP9v3) to address this issue. The aim of this phase Ib/IIa trial was to assess the safety of CUSP9v3.

Methods

Ten adults with histologically confirmed GBM and recurrent or progressive disease were included. Treatment consisted of aprepitant, auranofin, celecoxib, captopril, disulfiram, itraconazole, minocycline, ritonavir, and sertraline added to metronomic low-dose temozolomide. Treatment was continued until toxicity or progression. Primary endpoint was dose-limiting toxicity defined as either any unmanageable grade 3–4 toxicity or inability to receive at least 7 of the 10 drugs at ≥ 50% of the per-protocol doses at the end of the second treatment cycle.

Results

One patient was not evaluable for the primary endpoint (safety). All 9 evaluable patients met the primary endpoint. Ritonavir, temozolomide, captopril, and itraconazole were the drugs most frequently requiring dose modification or pausing. The most common adverse events were nausea, headache, fatigue, diarrhea, and ataxia. Progression-free survival at 12 months was 50%.

Conclusions

CUSP9v3 can be safely administered in patients with recurrent GBM under careful monitoring. A randomized phase II trial is in preparation to assess the efficacy of the CUSP9v3 regimen in GBM.

Bcl-2/Bcl-xL inhibition predominantly synergistically enhances the anti-neoplastic activity of a low-dose CUSP9 repurposed drug regime against glioblastoma

BACKGROUND AND PURPOSE

Drug repurposing represents a promising approach to safely accelerate the clinical application of therapeutics with anti-cancer activity. In this study, we examined whether inhibition of the anti-apoptotic Bcl-2 family proteins Bcl-2 and Bcl-xL enhances the biological effects of the repurposed CUSP9 regimen in an in vitro setting of glioblastoma.

EXPERIMENTAL APPROACH

We applied 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays to assess cellular proliferation. Annexin V/propidium iodide and tetramethylrhodamine, ethyl ester staining were used to examine apoptosis. Western blotting, RT-PCR, and specific knockdown experiments using siRNA were employed to examine molecular mechanisms of action.

KEY RESULTS

Bcl-2/Bcl-xL inhibition exerted synergistic anti-proliferative effects across established, primary cultured, and stem-like glioblastoma cells when combined with CUSP9 which had been reduced to only one tenth of its proposed original concentration (CUSP9-LD). The combination treatment also led to enhanced apoptosis with loss of mitochondrial membrane potential and activation of caspases. On the molecular level, CUSP9-LD counteracted ABT263-mediated up-regulation of Mcl-1. Silencing of Mcl-1 enhanced ABT263-mediated apoptosis which indicates that down-regulation of Mcl-1 is crucial for the induction of cell death by the combination treatment.

CONCLUSION AND IMPLICATIONS

These data suggest that Bcl-2/Bcl-xL inhibition enhances the susceptibility of glioblastoma cells towards CUSP9, allowing dramatic dose reduction and potentially decreased toxicity when applied clinically. A clinical trial involving the original CUSP doses (CUSP9v3) is currently ongoing in our institution (NCT02770378). The Bcl-2/Bcl-xL inhibitor ABT263 is in clinical trials and might represent a valuable adjunct to the original CUSP.

Glioblastoma-synthesized G-CSF and GM-CSF contribute to growth and immunosuppression: Potential therapeutic benefit from dapsone, fenofibrate, and ribavirin

Increased ratio of circulating neutrophils to lymphocytes is a common finding in glioblastoma and other cancers. Data reviewed establish that any damage to brain tissue tends to cause an increase in G-CSF and/or GM-CSF (G(M)-CSF) synthesized by the brain. Glioblastoma cells themselves also synthesize G(M)-CSF. G(M)-CSF synthesized by brain due to damage by a growing tumor and by the tumor itself stimulates bone marrow to shift hematopoiesis toward granulocytic lineages away from lymphocytic lineages. This shift is immunosuppressive and generates the relative lymphopenia characteristic of glioblastoma. Any trauma to brain—be it blunt, sharp, ischemic, infectious, cytotoxic, tumor encroachment, or radiation—increases brain synthesis of G(M)-CSF. G(M)-CSF are growth and motility enhancing factors for glioblastomas. High levels of G(M)-CSF contribute to the characteristic neutrophilia and lymphopenia of glioblastoma. Hematopoietic bone marrow becomes entrained with, directed by, and contributes to glioblastoma pathology. The antibiotic dapsone, the lipid-lowering agent fenofibrate, and the antiviral drug ribavirin are Food and Drug Administration– and European Medicines Agency–approved medicines that have potential to lower synthesis or effects of G(M)-CSF and thus deprive a glioblastoma of some of the growth promoting contributions of bone marrow and G(M)-CSF.

Ten-Step Minimally Invasive Spine Lumbar Decompression and Dural Repair Through Tubular Retractors

BACKGROUND: Minimally invasive spine (MIS) surgery utilizing tubular retractors has become an increasingly popular approach for decompression in the lumbar spine. However, a better understanding of appropriate indications, efficacious surgical techniques, limitations, and complication management is required to effectively teach the procedure and to facilitate the learning curve.

OBJECTIVE: To describe our experience and recommendations regarding tubular surgery for lumbar disc herniations, foraminal compression with unilateral radiculopathy, lumbar spinal stenosis, synovial cysts, and dural repair.

METHODS: We reviewed our experience between 2008 and 2014 to develop a step-by-step description of the surgical techniques and complication management, including dural repair through tubes, for the 4 lumbar pathologies of highest frequency. We provide additional supplementary videos for dural tear repair, laminotomy for bilateral decompression, and synovial cyst resection.

RESULTS: Our overview and complementary materials document the key technical details to maximize the success of the 4 MIS surgical techniques. The review of our experience in 331 patients reveals technical feasibility as well as satisfying clinical results, with no postoperative complications associated with cerebrospinal fluid leaks, 1 infection, and 17 instances (5.1%) of delayed fusion.

CONCLUSION: MIS surgery through tubular retractors is a safe and effective alternative to traditional open or microsurgical techniques for the treatment of lumbar degenerative disease. Adherence to strict microsurgical techniques will allow the surgeon to effectively address bilateral pathology while preserving stability and minimizing complications.