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US-20260124444-A1 - MODIFYING PH OF TISSUE TO REVERSE IMMUNOSUPRESSION

US20260124444A1US 20260124444 A1US20260124444 A1US 20260124444A1US-20260124444-A1

Abstract

Embodiments of the present invention include methods of targeting acidosis (low pH) within the tumor microenvironment (TME) through the use of cathodic electrochemical reactions (CER). Low pH is oncogenic by supporting immunosuppression. Electrochemical reactions create local pH effects when a current passes through an electrolytic substrate such as biological tissue. Electrolysis has been used with electroporation (destabilization of the lipid bilayer via an applied electric potential) to increase cell death areas. However, the regulated increase of pH through only the cathode electrode has been ignored as a possible method to alleviate TME acidosis, which could provide substantial immunotherapeutic benefits. Here, ex vivo modeling shows that CERs can intentionally elevate pH to an anti-tumor level and that increased alkalinity promotes activation of naïve macrophages. Embodiments of the invention include pairing CER treatment protocols with existing electric field-based cancer therapies or use as a stand-alone therapy.

Inventors

  • Rafael V. Davalos
  • Zaid Samer Salameh
  • Kenneth N. Aycock

Assignees

  • VIRGINIA TECH INTELLECTUAL PROPERTIES, INC.

Dates

Publication Date
20260507
Application Date
20231011

Claims (19)

  1. 1 . A method of providing electrical energy therapy comprising: applying a first set of electrical pulses to a target region sufficient to induce high-frequency irreversible electroporation (H-FIRE) or irreversible electroporation (IRE); and applying a second set of electrical pulses to the target region insufficient to induce electroporation, and sufficient to change the pH of the target region, by way of a cathode electrode disposed at the target region and an anode electrode disposed away from the target region.
  2. 2 . The method of claim 1 wherein: the first set of electrical pulses comprises: 50-200 microsecond IRE pulses of at a voltage ranging from 1,000 V to 5,000 V; or 1-10 microsecond H-FIRE pulses at a voltage ranging from 1,000-5,000 V; and delivering a second set of electrical pulses capable of changing the pH by increasing or decreasing pH by 1-2 units within the target region; wherein the first set of pulses is delivered before, after or during the second set of pulses.
  3. 3 . The method of claim 2 , wherein: the first set of electrical pulses are monopolar IRE pulses delivered at a rate of 1 Hz, with off time between the IRE pulses; or the first set of electrical pulses are H-FIRE pulses delivered at a burst rate of 1 Hz for a total on time of 100 microseconds per burst.
  4. 4 . The method of claim 3 , wherein the second set of electrical pulses are DC pulses or high-frequency, monophasic pulses.
  5. 5 . The method of claim 1 comprising: increasing the pH of a tumor from acidic to homeostatic by applying the second set of pulses as a select number of a select length of DC pulses or high-frequency, monophasic pulses for a select period of time sufficient to raise the pH; and reversing immunosuppression of a tumor microenvironment.
  6. 6 . The method of claim 4 , wherein: the second set of pulses comprises DC pulses having a length of from 1-1,000 seconds, which are applied for a total on time in the range of 10-1,000 seconds, and which are applied at a voltage ranging from 10-250 V and a current in the range of 0.5 A to 10 A.
  7. 7 . The method of claim 1 comprising: applying the second set of pulses in a manner to increase pH and elevate an immune response or in a manner to decrease pH and suppress inflammatory response.
  8. 8 . The method of claim 1 , wherein: the first set of electrical pulses are IRE pulses: in the range of 100-300 pulses, delivered with off time between the pulses; delivered at a voltage in the range of 1,000-3,000 V; and having a length of from 50-100 microseconds; and the second set of electrical pulses: comprises monophasic, high-frequency pulses of from 1-100 microseconds with delays between pulses of from 1 microsecond to 1 second, or comprises DC pulses with a length of from 1-1,000 seconds; is applied for a total on time in the range of 10-1,000 seconds; and is applied at a voltage of 10-250 V and a current in the range of 0.5-10 A.
  9. 9 . The method of claim 1 , wherein: the first set of electrical pulses: comprises a number of H-FIRE pulses in the range of 100-300 pulses, each having a length of from 1-10 microseconds; and is applied at a voltage of 1,000-3,000 V; and the second set of electrical pulses: comprises monophasic, high-frequency pulses or comprises DC pulses; and is applied at a voltage of 10-250 V and a current in the range of 0.5-10 A.
  10. 10 . The method of claim 1 , wherein: the second set of pulses is delivered in a manner to increase the pH from acidic to basic.
  11. 11 . The method of claim 1 , wherein the second set of pulses: comprises pulses having a pulse length of 1 microsecond to 10 seconds; comprises 10-100 pulses; and is applied at a voltage in the range of 10-100 V.
  12. 12 . The method of claim 1 , wherein the change in pH is an increase or decrease in pH of 1-2 units.
  13. 13 . The method of claim 1 , wherein the first and/or second set of electrical pulses are AC pulses, DC pulses, or a combination of AC and DC pulses.
  14. 14 . The method of claim 1 , wherein: the applying of the first and second set of electrical pulses comprises applying a plurality of electrical pulses to a tissue of the target region, wherein the plurality of electrical pulses is capable of causing electroporation and electrolysis of the tissue.
  15. 15 . A method comprising: administering a plurality of electrical pulses to a tumor by way of a cathode electrode disposed at the tumor site and an anode electrode disposed at another site, with the surface area of the anode relatively larger than the surface area of the cathode, wherein the plurality of electrical pulses is administered in a manner capable of: changing the pH of the tumor microenvironment; and/or causing a desired immune response; and/or improving immune cell infiltration; and/or controlling immune cell phenotype.
  16. 16 . A method comprising: connecting one or more or multiple probes to the cathode of a pulse generator; connecting a ground electrode to the anode of the pulse generator; and delivering a plurality of electrical pulses to a treatment area; wherein at least one pulse of the plurality of electrical pulses is capable of causing irreversible electroporation of at least some cells in the treatment area; and wherein at least one pulse of the plurality of electrical pulses is capable of changing the pH of the treatment area by isolating alkaline reactions generated at the treatment area thereby reversing an acidic microenvironment of the treatment area.
  17. 17 . The method of claim 16 , wherein the ground electrode is a distant ground electrode that is a surface electrode.
  18. 18 . The method of claim 16 , wherein at least one pulse of the plurality of electrical pulses is applied at a voltage capable of changing the pH, but below a voltage threshold capable of nerve excitation and/or irreversible electroporation.
  19. 19 . The method of claim 1 , further comprising measuring the change in pH.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application relies on the disclosure of and claims priority to and the benefit of the filing date of U.S. Provisional Application No. 63/414,942 filed Oct. 11, 2022, which is hereby incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to the field of electrical energy based treatments. Description of Related Art Acidity (low pH) is an oncogenic characteristic of the tumor microenvironment, supporting immunosuppression and tumor expansion (Huber, V. et al. Cancer acidity: An ultimate frontier of tumor immune escape and a novel target of immunomodulation. Semin. Cancer Biol. 43:74-89, 2017). Low pH arises from increased production of lactate and hydrogen ions in malignant cells that increasingly rely on aerobic glycolysis (Warburg effect) (Liberti, M. V., and J. W. Locasale. The Warburg Effect: How Does it Benefit Cancer Cells? Trends Biochem. Sci. 41:211-218, 2016). At a lower pH, T lymphocytes and natural killer (NK) cell function decrease and cells may become apoptotic (Calcinotto, A. et al. Modulation of microenvironment acidity reverses anergy in human and murine tumor-infiltrating T lymphocytes. Cancer Res. 72:2746-2756, 2012; Loeffler, D. A. et al. Natural killer-cell activity under conditions reflective of tumor micro-environment. Int. J. Cancer 48:895-899, 1991). Conversely, immuno-suppressive cells (regulatory T cells) activate (Watson, M. J. et al. Metabolic support of tumour-infiltrating regulatory T cells by lactic acid. Nature 591:645-651, 2021) and tumor-associated macrophages (TAMs) transform into a pro-tumor phenotype (El-Kenawi, A. et al. Acidity promotes tumour progression by altering macrophage phenotype in prostate cancer. Br. J. Cancer 121:556-566, 2019). Therefore, tumor acidity is a critical regulator of cancer immunity that orchestrates both local and systemic immunosuppression (Damgaci, S. et al. Hypoxia and acidosis: immune suppressors and therapeutic targets. Immunology 154:354-362, 2018), providing a need for therapeutic targets. Previous studies have targeted tumor pH using oral buffers (sodium bicarbonate) to elevate the TME pH and encourage immune cell infiltration (Pilot, C., A. Mahipal, and R. J. Gillies. Buffer Therapy→Buffer Diet. J. Nutr. Food Sci. 08: 2018). While effective in preventing metastases, sodium bicarbonate therapy does not address the primary tumor when used as a monotherapy (Robey, I. F. et al. Bicarbonate Increases Tumor pH and Inhibits Spontaneous Metastases. Cancer Res. 69:2260-2268, 2009). Recently, a combinatorial therapy of ethanol ablation (to treat the primary tumor) in conjunction with oral sodium bicarbonate (to elevate tumor pH) and cyclophosphamide (to deplete regulatory T cells) proved effective in treating the primary tumor and in preventing metastases (Nief, C. A. et al. Targeting Tumor Acidosis and Regulatory T Cells Unmasks Anti-Metastatic Potential of Local Tumor Ablation in Triple-Negative Breast Cancer. Int. J. Mol. Sci. 23:8479, 2022). One neoplasm associated with chronic inflammation (and an oncogenic TME) is Hepatocellular Carcinoma (HCC) (Coussens, L. M., and Z. Werb. Inflammation and cancer. Nature 420:860-867, 2002), which leads to sustained changes in both the innate hepatic immune response and systemic immune cell infiltration (Ringelhan, M. et al. The immunology of hepatocellular carcinoma. Nat. Immunol. 19:222-232, 2018). Surgical resection (transplant or partial hepatectomy) currently provides the best clinical strategy to treat HCC patients but can be limited by late diagnosis, tumor size and/or location, underlying pathology, and lack of organs for transplant (Balogh, J. et al. Hepatocellular carcinoma: a review. J. Hepatocell. Carcinoma 3:41-53, 2016). Although thermal ablation (radiofrequency and microwave ablation (RFA/MWA)) has emerged as a viable alternative to resection for liver neoplasms (Llovet, J. M. et al. Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma. Nat. Rev. Gastroenterol. Hepatol. 18:293-313, 2021), the indiscriminate tissue damage arising within the ablative zone can lead to challenges when ablating tumors located near critical structures. Irreversible electroporation (IRE) has emerged as an alternative to thermal ablation (Davalos, R. V. et al. Tissue Ablation with Irreversible Electroporation. Ann. Biomed. Eng. 33:223-231, 2005). With IRE systems a high voltage electrical potential is delivered in short pulses (80-100 μs) across the target region between appropriately placed electrodes leading to the formation of nanodefects in the lipid bilayer of cells within the electric field. These nanodefects can lead to loss of homeostasis and induce cell death pathways (Aycock, K. N., and R. V. Davalos. Irreversible Electroporation: Background, Theory, and Review of Recent Developments in Clinical Oncology. Bioelectricity 1:214-234, 2019). Unlik