Sonodynamic therapy is an emerging therapeutic approach against brain tumours. However, the treatment scheme and ultrasound parameters have yet to be explored for clinical translation. Our study aimed to optimize ultrasound parameters for sonodynamic therapy (SDT) with 5-ALA as a sonosensitizing agent and to evaluate its therapeutic outcome on the rodent 9L gliosarcoma and the human U87 glioblastoma models. We stereotactically implanted brain tumour cells in rats and monitored tumour volume via MRI. SDT was conducted weekly using a 60 mg/kg dose of 5-ALA, injected intravenously 6 h before sonication. We used a driving frequency of 580 kHz with 0.75 MPa and evaluated the effect of different burst lengths to optimize ultrasound parameters. We also tested SDT against advanced-stage brain tumours to verify its efficacy further. Our results showed that a longer burst length could improve therapeutic outcomes. Tumour growth inhibition was established only in the first three weeks with 10 ms and 50 ms burst length sonication, but 86 ms burst length greatly improved the survival outcome. Therefore, the therapeutic efficacy is proportionate to the burst length and, thus, the total delivered energy. Repeated SDT using multiple targets to cover the entire tumour volume with optimal ultrasound parameters can achieve significant anti-tumour effects in both 9L and U87 models. Lastly, our results on late-stage tumour treatments showed that SDT can still provide prolonged survival. These promising findings demonstrate that repeated SDT using transcranial-focused ultrasound together with 5-ALA can optimize anti-tumour effects and even lead to complete clearance of the tumours. This weekly treatment with pulsed ultrasound sonication strategy is practical for future clinical translation.

Hematologic malignancies constitute a diverse group of diseases, each characterized by distinct pathophysiological features. These include, in part, acute and chronic forms of lymphoblastic leukemia (ALL and CLL), acute and chronic forms of myeloid leukemia (AML and CML) multiple myeloma (MM), and myelodysplastic syndrome (MDS). Although many forms of therapy exist which may produce initial disease remission, recurrence and/or progression of these diseases present formidable challenges in treatment efficacy. We propose targeting the heme pathway via sonodynamic therapy (SDT) as a tailored drug-device combination treatment modality to optimize patient outcomes avoiding the debilitating side effects of chemotherapy, immunotherapy, radiation, and bone marrow transplantation, all which comprise current standard of care. The drug, 5-aminolevulinic acid (5-ALA, SONALA-001), is the first committed intermediate in the heme biosynthetic pathway while the device provides low-intensity focused ultrasound. When 5-ALA is provided in excess amounts to rapidly growing cancer cells, it is taken up by those cells in great quantities and converted to protoporphyrin IX (PpIX), a photoactive molecule which accumulates in cancer cells. PpIX fluorescence detection is an FDA-approved use as a visual aid for neurosurgeons and urologists to identify brain and bladder cancers, respectively. When activated by light of an energy higher than that which results in fluorescence, PpIX transfers its energy to molecular oxygen in the cell, creating a highly reactive, short-lived oxygen species, singlet oxygen. Photodynamic therapy (PDT) specifically kills tumor cells through a combination of necrosis (caused by immediate tumor cell death via lipoperoxidation of the cell membrane) and programmed cell death (apoptosis) caused by lipoperoxidation of the mitochondrial membrane and release of cytochrome C. The lower level of PpIX accumulation in normal healthy cells should translate to a significant therapeutic index favoring death of the malignant cells. Topical 5-ALA PDT is FDA-approved for the treatment of precancerous skin lesions (actinic keratoses) and has treated over 5 million subjects since approval. To determine the potential for 5-ALA PDT to treat hematologic malignancies, we sought to determine the 5-ALA incubation time and dose for maximal PpIX accumulation across a panel of hematologic cancers using commercially available cell lines, and isolated PBMCs and bone marrow (BMMCs) samples from both normal controls and cancer patients. In some cases, PBMCs and BMMCs from the same patient were evaluated. To determine peak PpIX accumulation, we exposed cells to various 5-ALA concentrations (0.3-1mM) and measured PpIX fluorescence over time (2-24hrs) using either a plate reader or flow cytometer. For our initial studies we used a fluorescent plate reader with multiple cell lines (e.g. Jurkat, RPMI-8226, K562). For healthy and patient-derived PBMC and BMMCs (e.g. AML, CML, MDS), we assessed PpIX accumulation using flow cytometry. For experiments conducted using hematologic cancer patient samples (PBMCs), we first sought to determine whether results from samples with high proportion of blast (high blasts) cells differed from those with a low proportion of blast cells (mid/low blasts). We observed a bias toward greater PpIX accumulation in the CD45 mid/low population (high proportion of blast cells) as compared to the CD45 high (low proportion blast cell population). In vitro PDT studies showed that cell death was dependent on PpIX accumulation in models of leukemia and myeloma (e.g. T-ALL, MM, and CML), whereas cells receiving 5-ALA, but no UV light exposure appeared unaffected. We propose that these results demonstrate the potential 5-ALA/PDT as treatment for leukemic cell populations in vivo. While the use of ALA PDT would restrict our treatment to a form of extracorporeal photopheresis, we propose to develop ultrasound as a source of photons (via sonoluminescence). This would allow us to treat circulating blood in situ noninvasively and would also have the potential to treat bone marrow infiltrated with malignant cells.This research was, in part, funded by the Advanced Research Projects Agency for Health (ARPA-H). The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the United States Government.

INTRODUCTION: Diffuse intrinsic pontine glioma (DIPG) is the leading cause of mortality amongst pediatric neuro-oncologic diseases. Sonodynamic therapy with MR-guided focused ultrasound (MRgFUS) is being investigated in multiple clinical trials. METHODS: Twelve patients with DIPG were treated from August 2022-April 2024 as part of a dose-escalation protocol with SDT in a multicenter Phase 1/2 clinical trial (NCT05123534). MRgFUS was combined with the prodrug SONALA-001 (5-ALA iv) to activate its metabolite, protoporphyrin IX, and thereby induce apoptosis within tumor cells. Treatment is delivered every 4 weeks for up to 12 treatments. RESULTS: Patient ages ranged from 3-23 years and 60% were male. Twelve patients underwent a total of 45 SDT treatments (range: 2-9). When enrolled, median tumor volume was 1,337 cm3 (range: 310-2078 cm3) and duration since diagnosis was 5 months. SONALA-001 doses tested were 5 mg/kg and 10 mg/kg. Delivered ultrasonic acoustic energy ranged from 190-444 joules/cm3. After 6 months of median follow-up (range: 2-18), 2 partial responses occurred, and 9 of 12 patients had stable or improved baseline symptoms (Lansky Status), including improved mobility and diplopia. One adverse clinical event included a small non-operative epidural hematoma secondary to a stereotactic frame pin. There have been no grade 3 or worse treatment-related adverse events or dose-limiting toxicities. Ten patients are alive a median of 11 months after diagnosis; 2 have deceased; 4 have discontinued treatment. Maximum percent tumor volume changes throughout treatment ranged from a -68% reduction to over 100% enlargement. CONCLUSIONS: Preliminary analysis of twelve pediatric patients treated with SDT for DIPG demonstrates acceptable safety outcomes and promising clinical results. Additional patient enrollment and longer follow-up times are required to determine efficacy.

Sonodynamic therapy (SDT) is a novel treatment modality in glioblastoma (GBM) that relies on combining non-ablative sonication of tumor tissue via focused ultrasound with administration of 5-amino-levulinic acid (5ALA), to induce tumor cell kill. A multi-institutional Phase 1/2 clinical trial evaluating the safety and preliminary efficacy of SDT in recurrent GBM is currently underway (NCT05370508). In preclinical studies, SDT has been shown to cause oxidative stress and induce apoptosis in glioma cells leading to inhibition of tumor growth and increased survival in rodent glioma models. However, it remains unclear whether this paradigm has functional anti-tumor effects at the cellular level in clinical GBM patients. A subject with recurrent multifocal GBM, who was already enrolled in the Phase 1 trial, underwent planned resection of a progressing focus of disease one day after SDT. Within the focus, SDT was applied to half of the tumor territory. After informed consent, resected tumor was used to establish regional patient-derived cultures from treated and untreated tissue. Cells from SDT-treated and untreated tumor territories were subjected to tumorsphere formation assays, which assess clonogenic potential, a property that has been ascribed to stem-like GBM cells. Cells from treated regions of the tumor formed fewer spheres compared to untreated regions, suggesting SDT-induced impairment in clonogenic ability. Our data constitute the first proof-of-concept analysis of in-human functional effects of SDT on GBM clonogenicity and tumor growth. We are currently pursuing additional functional characterization, as well as in-depth analysis of molecular biomarkers in SDT-treated and untreated tumor regions.

2067 Background: Children with DIPG have limited treatment options and a poor prognosis, with median survival of 9-12 months. Preclinical studies reveal that sonodynamic therapy (SDT) with MR-guided focused ultrasound (MRgFUS) activates ALA metabolite, protoporphyrin IX (PpIX), leading to tumor cell death and extending survival in glioma models. Methods: SDT-201 (NCT05123534) is a multi-center, first-in-child dose escalation trial of SDT with SONALA-001 and MRgFUS administered in children aged ≥ 5 years with DIPG, enrolled 4-20 weeks post-radiation therapy and prior to disease progression. The trial evaluates the safety and preliminary efficacy of SDT and pharmacokinetics (PK) of intravenous ALA (SONALA-001) at 5mg/kg, administered 6-12 hours before MRgFUS to the pons (delivered to half the pons 30 days apart for the first patient in each cohort of 3, with subsequent patients receiving entire pons treatment). The trial was subsequently amended to allow up to 12 monthly treatments. Results: Six patients in 2 cohorts were treated (4 male:2 female, range 5-12 years) between August 2022 and December 2023. No DLTs or related AE grade ≥ 3 were observed. For SONALA-001, the Cmax occurred at the end of infusion, followed by rapid clearance (15.7 mL/min/kg) with plasma half-life of < 1 hour, indicating rapid distribution. The PpIX Cmax occurred 4-6 hours post-dose and declined with a longer mean half-life than SONALA-001 of 6 hours. Both Cmax and AUCall demonstrate circulating-PpIX and systemic exposure were significantly lower than for SONALA-001. Two of the first 6 patients achieved a partial response per RAPNO central-review, and 2 subjects continuing treatment are 11 to 15 months from start of study therapy. Conclusions: SDT is a well-tolerated strategy for patients with DIPG after initial radiotherapy. SONALA-001 shows rapid distribution and clearance, and PpIX PK align with metabolite formation. Following dose escalation completion, dose-expansion will be initiated at RP2D offering further insights into safety, PK, and efficacy. Clinical trial information: NCT05123534 .

Abstract BACKGROUND Children with DIPG have limited treatment options and poor prognosis with median survival of 9-12 months. Preclinical studies reveal that sonodynamic therapy (SDT) via MR-guided focused ultrasound (MRgFUS) activates SONALA-001 (ALA) metabolite, protoporphyrin IX (PpIX), inducing tumor cell death and extending survival in glioma models. METHODS We present preliminary data from an ongoing first-in-child drug-device trial (NCT05123534) of SONALA-001 SDT in children with DIPG aged ≥ 5 years post-radiation therapy. The trial evaluates the safety of ALA-SDT, preliminary efficacy and pharmacokinetics (PK) of SONALA-001 at 5mg/kg administered 6-12 hours before SDT and establishes the RP2D. Each cohort involves three subjects: the first receiving half-pons treatment 30-days apart; the others receiving entire pons treatment. Single-treatment approach was amended to allow up to 12 monthly-treatments. RESULTS Six patients (4M:2F, 5-12 years) in 2 cohorts received 22 SDT-treatments between August 2022 and February 2023. Sonication duration averaged 147 minutes. Five of 6 patients received repeated treatments. All were discharged post-procedure day 1 with no DLTs or related AE grade ≥ 3. For SONALA-001, the Cmax occurred at end of infusion, followed by rapid clearance (15.7 mL/min/kg); plasma half-life of < 1 hour, indicating rapid distribution. The PpIX-Cmax occurred 4-6 hours post-dose, declining with a longer mean half-life than SONALA-001 of 6 hours. Both Cmax and AUCall demonstrate circulating-PpIX and systemic exposure were significantly lower than for SONALA-001. Two of 6 patients achieved a partial response per RAPNO central-review, and 2 continue in the study treatment for 11 and 15 months, respectively. CONCLUSION SDT is an innovative and to-date well-tolerated strategy for children with DIPG post-initial radiotherapy. Sonications did not result in any adverse procedural effects. SONALA-001 exhibits rapid distribution and clearance, while PpIX PK align with metabolite formation. After dose escalation completion, dose-expansion at R2PD will offer insights into safety, PK, and efficacy.

ALA PDT, first approved as a topical therapy to treat precancerous skin lesions in 1999, targets the heme pathway selectively in cancers. When provided with excess ALA, the fluorescent photosensitizer PpIX accumulates primarily in cancer tissue, and ALA PDD is used to identify bladder and brain cancers as a visual aid for surgical resection. ALA PDT has shown promising anecdotal clinical results in recurrent glioblastoma multiforme. ALA SDT represents a noninvasive way to activate ALA PDT and has the potential to achieve clinical success in the treatment of both intracranial and extracranial cancers. This review describes the creation and evolution of ALA PDT, from the treatment of skin cancers to PDD and PDT of malignant brain tumors and, most recently, into a noninvasive form of PDT, ALA SDT. Current clinical trials of ALA SDT for recurrent glioblastoma and high-grade gliomas in adults, and the first pediatric ALA SDT clinical trial for a lethal brainstem cancer, diffuse intrinsic pontine glioma (DIPG), are also described.

Abstract Diffuse intrinsic pontine glioma (DIPG) is the leading cause of mortality amongst pediatric neuro-oncologic diseases. Sonodynamic therapy with non-ablative MR-guided focused ultrasound (MRgFUS) is being investigated in multiple clinical trials. We describe safety outcomes and initial efficacy of SDT with 5-ALA for the treatment of pediatric patients with DIPG. Twelve patients with DIPG were treated from August 2022-April 2024 as part of a dose-escalation protocol with SDT in a multicenter Phase 1/2 clinical trial (NCT05123534). MRgFUS was combined with the prodrug SONALA-001 (5-ALA iv) to activate its metabolite, protoporphyrin IX, and thereby induce apoptosis within tumor cells. Treatment is delivered every 4 weeks for up to 12 treatments. Patient ages ranged from 3-23 years and 60% were male. Twelve patients underwent a total of 45 SDT treatments (range 2-9). When enrolled, median tumor volume was 1,337 cm3 (range, 310-2078 cm3) and duration since diagnosis was 5 months. SONALA-001 doses tested were 5 mg/kg and 10 mg/kg. Delivered ultrasonic acoustic energy ranged from 190-444 joules/cm3. After 6 months of median follow-up (range 2-18), 2 partial responses occurred, and 9 of 12 patients had stable or improved baseline symptoms (Lansky Status), including improved mobility and diplopia. One adverse clinical event included a small non-operative epidural hematoma secondary to a stereotactic frame pin. There have been no grade 3 or worse treatment-related adverse events or dose-limiting toxicities. Ten patients are alive a median of 11 months after diagnosis; 2 have deceased; 4 have discontinued treatment. Maximum percent tumor volume changes throughout treatment ranged from a -68% reduction to over 100% enlargement. Preliminary analysis of twelve pediatric patients treated with SDT for DIPG demonstrates acceptable safety outcomes and promising clinical results. Additional patient enrollment and longer follow-up times are required to determine efficacy.

TPS2101 Background: Recurrent glioblastoma (rGBM) is a lethal brain tumor with no effective therapy and an extremely poor prognosis (median survival 6 to 8 months after first recurrence). Sonodynamic therapy (SDT) is a non-invasive combination treatment that utilizes a drug, aminolevulinic acid HCL (SONALA-001), and a device, the Exablate 4000 Type 2.0, to deliver non-ablative MR-guided focused ultrasound (MRgFUS) to tumor. Preclinical studies have shown that SDT-induced sonoluminescence activates protoporphyrin IX (PpIX), which in turn generates reactive oxygen species that lead to tumor cell death and improved survival in animal glioma models. A first-in-human Phase 0 trial (NCT04559685) indicated that SONALA-001 SDT was well-tolerated and not associated with off-target cellular or radiographic effects, and provided direct evidence of reactive oxygen species formation and targeted tumor cell death in recurrent high-grade glioma (rHGG). Methods: SDT-202 is a Phase 1/2 multicenter, open-label, dose escalation and expansion study (NCT05370508) of 10 mg/kg iv SONALA-001 in combination with MRgFUS for SDT in patients with progressive or recurrent GBM. Treatments take place every 4 weeks. In phase 1, sonication energy escalation utilizes an accelerated titration design with a single subject for dose level 1, followed by cohorts 2 and 3 with 3+3 design for additional dose escalation. SONALA-001 is administered 6 to 12 hours prior to MRgFUS treatment. Once the RP2D is determined, Phase 2 dose expansion will enroll approximately 36 additional subjects to assess safety and efficacy of repeated cycles of SONALA-001 SDT at the optimized RP2D. Endpoints of this study are safety evaluation, maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and determination of pharmacokinetic (PK) parameters. The Phase 2 portion will further characterize safety of RP2D along with evaluation of efficacy with PFS6 (mRANO), ORR, CBR, DOR, DOCR, TTR, and OS. Clinical trial information: NCT05370508 .

Abstract Recurrent glioblastoma (rGBM) is a lethal brain tumor with no effective standard of care option and an extremely poor prognosis (median survival 6 to 8 months after first recurrence). Sonodynamic therapy (SDT) is a non-invasive combination therapy that utilizes a drug, aminolevulinic acid HCL (SONALA-001, ALA), and a device, the Exablate 4000 Type 2.0 to deliver MR-guided focused ultrasound (MRgFUS). Preclinical studies have shown that SDT activates protoporphyrin IX (PpIX) to generate reactive oxygen species that lead to tumor cell death and improved survival in animal glioma models. A first-in-human Phase 0 trial (NCT04559685) indicated that ALA SDT was well-tolerated and not associated with off-target cellular or radiographic effects and provided direct evidence of reactive oxygen species formation and targeted tumor cell death in recurrent high-grade glioma (rHGG). SDT-202 is a Phase 1/2 multicenter, open-label, dose escalation and expansion study (NCT05370508) of iv SONALA-001 (ALA) in combination with MRgFUS for SDT in patients with progressive or recurrent GBM. Dose escalation will include an initial drug and energy dose escalation of ALA SDT utilizing an accelerated titration design with single subject cohorts for dose level cohorts 1 and 2, followed by cohort 3 with 3 + 3 design for additional dose escalation. SONALA-001 is administered 6 to 9 hours prior to MRgFUS treatment. Once the RP2D is determined, Phase 2 dose expansion will enroll approximately 36 additional subjects to assess safety and efficacy of repeated cycles of ALA SDT at the optimized RP2D. Endpoints of this study are safety evaluation, maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and determination of pharmacokinetic (PK) parameters. The Phase 2 portion will further characterize safety of RP2D along with evaluation of efficacy with PFS6 (mRANO), ORR, CBR, DOR, DOCR, TTR, and OS. Preliminary PK and safety results will be presented.

Abstract BACKGROUND DIPGs are devastating pediatric brain tumors with limited treatment options, poor prognosis, and survival of 9-11 months. Preclinical studies demonstrate that performing SDT through MR-guided focused ultrasound (MRgFUS) activates ALA metabolite, protoporphyrin IX (PpIX), leading to tumor cell death and prolonging survival in rodent glioma models through generation of reactive oxygen species and lipoperoxidation, without affecting normal tissue. MEDTHODS: Herein we report preliminary data from an ongoing first-in-child dose-escalation trial of ALA-SDT post-radiation therapy in children ≥ 5 years with DIPG. The trial aims to evaluate the safety and tolerability of ALA-SDT, determine the recommended-phase-2-dose and assess preliminary efficacy and pharmacokinetics (PK) of ALA administered intravenously. RESULTS The first study cohort completed enrollment of 3 subjects. Six hours prior to SDT, patients received an infusion of ALA (SONALA-001) at a dose of 5 mg/kg, followed by sonication with 200J. The first subject was treated in 2 sessions: each to half of the pons 30 days apart. Two subsequent subjects had the entire pons treated in a single session. No dose-limiting toxicity (DLT) or related adverse event grade ≥ 3 were observed. For SONALA-001, the Cmax occurred at the end of infusion, followed by rapid clearance (15.7 mL/min/kg), with a plasma half-life of < 1 hour, indicating rapid distribution (5530 ml/kg). For PpIX, the Cmax occurred 6 hours post-dose and declined with a longer mean half-life of 3.8 hours. Both Cmax and AUCall demonstrate circulating PpIX and systemic exposure were significantly lower than for ALA. CONCLUSION SDT signals an innovative and well-tolerated approach for patients with DIPG in our first study cohort. As expected, the PK for SONALA-001 demonstrate rapid infusion and clearance, whereas for PpIX, the PK are consistent with formation of a metabolite. Clinical trial enrollment is ongoing and dose-escalation cohorts will provide additional PK and safety data.

TPS10070 Background: Diffuse intrinsic pontine glioma (DIPG) is a devastating pediatric brain tumor with poor prognosis. Sonodynamic therapy (SDT) with ALA is a non-invasive strategy that sensitizes target tissues with a non-toxic chemical agent followed by exposure to low intensity MR-guided focused ultrasound (MRgFUS). Preclinical studies have shown that ALA is preferentially taken up by glioma cells and metabolized to protoporphyrin IX (PpIX). SDT activates protoporphyrin IX and induces tumor cell death via photodynamic effect (lipoperoxidation, apoptosis). Suheiro et al and Wu et al demonstrated that SDT killed tumors via apoptosis and lipoperoxidation in rodent glioma models with minimal damage to surrounding normal brain. 1,2 ALA SDT was well-tolerated in an ongoing first-in-human trial in adults with recurrent high-grade gliomas and demonstrated biomarker evidence of the photodynamic effect 3 . Methods: A Phase 1/2, multicenter, open label study (NCT05123534) is enrolling patients at Children’s National Hospital. The study employs the Bayesian optimal interval (BOIN) algorithm to evaluate safety and tolerability of treatment with SDT in newly diagnosed DIPG subjects to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of MRgFUS energy in combination with ALA. The study will evaluate 3 ALA doses and 3 acoustic energy doses. ALA is administered IV six to nine hours prior to MRgFUS with the Exablate type-2 device. The first cohort, B1C1, evaluates the lowest drug-device dose combination and if no dose-limiting toxicity (DLT) is encountered after 3 patients, ascending dose-escalation will proceed to the second cohort, B2C1, treated with lowest dose of ALA with the second level of MRgFUS energy. Again, if no DLT is experienced, the next cohort will receive a higher dose combination. The initial patient in each cohort is treated in 2 sessions 21 to 28 days apart, each covering one-half of the pons. Subsequent patients are treated in 1 session to the whole pons. The primary objective is to evaluate the safety and tolerability of SDT in DIPG subjects. Secondary outcomes include preliminary efficacy assessments, pharmacokinetics of ALA and PpIX, mechanical performance of the Exablate Type-2 device, and radiographic evidence of tumor physiological changes associated with SDT. All patients at least 5 years of age with newly diagnosed, radiographically typical DIPG between 4-24 weeks after completion of standard radiotherapy are eligible for the trial. Patients with evidence of disease progression, diagnosis of porphyria, or prior or concurrent therapy with any other anticancer or investigational intervention will be excluded. Cohort 1 has been completed without DLT. References: 1. Suheiro et al. J Neurosurg 2018;129:1416-1428. 2. Wu et al. Sci Rep 2019;9:10465. 3. Sanai et al. NeuroOnco 2022;24(&):vii72-vii73. Clinical trial information: NCT05123534 .

To the Editor: 5-Aminolevulinic acid photodynamic therapy demonstrates better curative effects with lower recurrence rates and fewer adverse effects than oral isotretinoin in the treatment of moderate and severe acne.1,2 Because pain is a major concern associated with conventional photodynamic therapy, more effective solutions are needed.

Abstract Heme biosynthesis is altered in glioblastoma (GBM). Systemic dosing with ALA, the first committed molecule in the heme pathway, results in accumulation of the fluorescent intermediate, protoporphyrin IX (PpIX) only within tumor tissue (Gleolan label, 2019). PpIX is a photosensitizer that is effective in photodynamic therapy (PDT); in recurrent GBM patients, the safety and feasibility of ALA PDT has been demonstrated (Johansson A, et al. Lasers Surg Med 2013;45:225), although the practicality of this strategy in clinical care remains uncertain. Importantly, preclinical models of GBM show that PpIX is also a sonosensitizer and, in combination with transcranial MRI-guided focused ultrasound (MRgFUS), leads to non-ablative cytotoxic effects in vivo (Jeong EJ et al, Ultrasound in Medicine and Biology 2013:38;2143, Suehiro S et al, J Neurosurg 2018: 1377, Wu et al Nature Sci Reports 2019: 9;10465). The Ivy Brain Tumor Center is conducting a first-in-human study of 5-ALA sonodynamic therapy (SDT) for recurrent GBM (NCT 04559685). In this Phase 0/1 clinical trial, nontherapeutic, single-treatment SDT is administered prior to planned tumor resection. A Dose-Escalation Arm varies the power/energy of the MRgFUS while using a fixed time-interval from exposure to surgery. A subsequent Time-Escalation Arm varies the interval between MRgFUS and surgical resection, but fixes the power/energy of the delivered ultrasound. In both Arms, patient tumor tissue is assessed for sonodynamic and pharmacodynamic effects. In each patient, half of the tumor volume is not targeted with SDT and serves as an internal control. This first-in-human study will demonstrate the safety and feasibility of ALA sonodynamic therapy in GBM and may provide the first-ever biological evidence of sonosensitization in a brain tumor patient. If successful, this Phase 0 trial will introduce a new, metabolically-driven, GBM treatment modality that may be applicable to any brain tumor that selectively accumulates PpIX after ALA administration.

BACKGROUND The relationship between actinic keratoses (AKs) and nonmelanoma skin cancers (NMSCs) is well established. Patients with field cancerization are at high risk of developing new lesions. A treatment to interrupt new lesion formation or progression is required. OBJECTIVE To evaluate occurrence of AKs in high-risk patients after field aminolevulinic acid–photodynamic therapy (ALA–PDT). METHODS In this randomized, parallel-group, evaluator-blinded, 52-week study, patients with 4–15 facial AKs (N = 166) were random-ized (ALA 2x vs ALA 3x vs vehicle [VEH]-pooled [VEH 2x+VEH 3x], 1:1:1) to receive 2 or 3 PDT treatments (1-hour incubation) following cryotherapy at screening. RESULTS More ALA-treated patients than VEH-treated patients had no AKs at week 52 (ALA 2x, 36.0%, P=0.0102; ALA 3x, 37.5%, P=0.0089; VEH, 18.9%). Week 52 lesion recurrence rates were 7.7% (P=0.0004) and 6.1% (P<0.0001) for ALA 2x and ALA 3x, respec-tively, versus 15.5% for VEH. Therapy was well tolerated; no patient requested early termination of light treatment. ALA 3x reduced NMSC development versus VEH (5 vs 12 lesions, P=0.0014). CONCLUSION 2 or 3 ALA–PDT treatments with 1-hour incubation can significantly reduce occurrence of AKs after 1 year in patients at high risk of NMSC versus VEH–PDT (NCT02239679). J Drugs Dermatol. 2020;19(5):452-458. doi:10.36849/JDD.2020.4930.