- The ZP-Glucagon patch uses novel microneedle technology to deliver glucagon through the skin to people who are experiencing severe hypoglycemia (very low blood sugar).
- There is very limited evidence, from one small study, comparing the ZP-Glucagon patch with glucagon injected intramuscularly.
- The evidence suggests that the correction of blood sugar levels is comparable between the ZP-Glucagon patch and the glucagon injected intramuscularly when tested in a controlled setting.
- The ZP-Glucagon patch is not yet commercially available and the anticipated cost is unknown.
- In an emergency situation, the ZP-Glucagon patch may be a more user-friendly option than injecting glucagon.
Hypoglycemia occurs when a person’s blood glucose (blood sugar) level is too low; it is a common problem in people living with diabetes who are on insulin or insulin secretagogues (drugs that increase insulin secretion by the pancreas).1 Although the precise thresholds for hypoglycemia and severe hypoglycemia based on blood glucose levels continue to be debated, the severity of hypoglycemia is generally categorized by the clinical symptoms and the type of intervention required.2,3 Common symptoms of mild or moderate hypoglycemia include difficulty concentrating, trembling, palpitations, sweating, anxiety, confusion, and vision changes.1 These are typically resolved with the administration of carbohydrates (for example, glucose tablets, juice, or honey).1
In severe hypoglycemia, the assistance of another person is required as the patient may experience a loss of consciousness, enter a coma, or have a seizure.1 Severe hypoglycemia is associated with both short-term risks (for example, when driving or operating machinery) and long-term complications (for example, potential intellectual impairment).1,2
Glucagon is the main hormone produced by the body in response to low blood glucose levels.4,5 It acts on the liver to release glucose into the blood to restore sugar levels to normal.4,5 Commercially available exogenous (external) glucagon is identical to human glucagon and is used to treat people with severe hypoglycemia who have lost consciousness.6 Commercial glucagon is supplied as a dry powder and must be mixed with diluent immediately before use and injected intramuscularly or subcutaneously.6
An alternative to mixing and injecting glucagon, a microneedle skin patch, is in development. This may be more user friendly in cases of glycemic emergencies.
Microneedle technology as a method of transdermal (through the skin) drug delivery has received a great deal of attention in recent years.7-10 Microneedles consist of micron-scale projections that are considered to be minimally invasive, yet are capable of bypassing the outermost layer of the skin (stratum corneum) without disrupting nerves and blood vessels, thereby inducing no pain or bleeding when applied.7,10 The microchannels that result from the projections form an unobstructed transport pathway big enough for large molecules such as proteins and peptides to pass through.7
The ZP-Glucagon patch (Zosano Pharma, Fremont, California) is a coin-sized patch that, when applied to the skin using a reusable applicator, delivers glucagon through the skin to ultimately be absorbed into the blood.
Zosano Pharma's proprietary ZP-patch system (which can be used for delivery of various drugs), consists of a 3 cm2 array of titanium microneedles in the centre of an adhesive patch contained within a retainer ring.11,12 The microneedles are dry-coated with the drug or compound to be administered (in this case, glucagon). The retainer ring is attached to the bottom of the applicator, which in turn, is activated through spring force. The applicator is positioned on the arm and depressed, causing the adhesive to break away from the retainer ring and the patch to be applied to the skin site.11 The patch remains applied for 30 minutes after which time it is removed and discarded.13
When the patch is applied, the microneedles physically break the outermost layer of skin, and penetrate the epidermis layer below where the dry drug coating is dissolved in the surrounding interstitial fluid.11 The outer layer of skin provides protection against external microbial pathogens, chemicals, and dehydration, and is also the principal barrier to drugs intended for transdermal delivery.7 This method of delivery results in rapid dissolution and absorption of administered drugs or compounds through the capillary bed, reaching the desired therapeutic levels in the blood within 20 minutes.12
The ZP-Glucagon patch is not yet commercially available in Canada or elsewhere. According to the company’s website (at the time of publication) the ZP-Glucagon patch is in phase II clinical development.14
The anticipated cost of the ZP-Glucagon patch is yet unknown.
Who Might Benefit?
Individuals with type 1 diabetes and type 2 diabetes who are at increased risk of drug- or insulin-induced hypoglycemia, especially those who are attempting intensive control to achieve strict glycemic targets.15
Severe hypoglycemia is less frequent in early diabetes because of the body’s defenses, which release glucagon and adrenalin to limit large falls in blood glucose.2 However, as diabetes progresses, the body’s ability to release glucagon is impaired and counter-regulatory responses are activated at lower blood glucose levels — which further increase the risk of severe hypoglycemia.2 As a result, it is important that people with diabetes who use insulin or insulin secretagogues know how to prevent, recognize, and treat hypoglycemic episodes that can occur because of their treatment with insulin — this includes the use of exogenous glucagon to counteract low blood glucose levels.1
The 2013 Canadian clinical practice guidelines on diabetes recommend that a conscious person with severe hypoglycemia should be treated with oral ingestion of 20 g of a carbohydrate, preferably as glucose tablets or an equivalent.1 The person's blood glucose level should be re-tested in 15 minutes and re-treated with another 15 g of glucose if the blood glucose level remains less than 4.0 mmol/L.1 For an unconscious person with severe hypoglycemia and no intravenous access, the guidelines recommend treatment with 1 mg glucagon given subcutaneously or intramuscularly, and that caregivers or support persons should call for emergency services.1 If there is intravenous access, then the preferred treatment is 10 g to 25 g of glucose given intravenously for one to three minutes.1
In Canada, exogenous glucagon is indicated for the emergency treatment of severe hypoglycemia in patients treated with insulin when unconsciousness prevents treatment with oral carbohydrates.6 Currently, glucagon is only available in Canada in powder form, meaning the powder must be reconstituted with the supplied diluent immediately before injection. The recommended dose for adults and children weighing more than 20 kg is 1 mg glucagon administered by subcutaneous, intramuscular, or intravenous injection.6 A subcutaneous or intramuscular dose of 1 mg glucagon increases mean peak blood glucose levels to approximately 7.5 mmol/L to 7.6 mmol/L within 30 minutes following the injection.6
The ZP-Glucagon patch is in early development and only one conference abstract16 and a clinical trial registration17 for a phase II study were identified. The study compared the safety and efficacy of two dose levels (0.5 mg and 1.0 mg) of glucagon administered by either the ZP-Glucagon patch or glucagon administered by intramuscular injection (GlucaGen, Novo Nordisk).16,17 The study was designed as a four-way, open-label, randomized, crossover study in 16 adults with type 1 diabetes who were made mildly hypoglycemic by infusing insulin. The primary outcome was the proportion of patients achieving normal blood glucose levels after 30 minutes.
Administration of 0.5 mg or 1.0 mg of glucagon by either the ZP-Glucagon patch or intramuscular injection resulted in normalization of glucose in all study patients. Both patch doses of glucagon had rapid onset of action and the time to response was similar for all four treatment groups.16
According to the conference abstract for the phase II study of the ZP-Glucagon patch, all treatments were well tolerated and no safety issues were reported.16 No further information on the safety and tolerability of the ZP-Glucagon patch was identified. Given the limited evidence available, potential safety concerns with the patch are yet unknown.
Zosano Pharma is also developing ZP patch transdermal delivery systems for other conditions.18 A ZP patch product containing zolmitriptan (ZP-Triptan) for migraine therapy is entering phase III trials and another ZP patch product containing parathyroid hormone (ZP-PTH) for use in osteoporosis has completed phase II trials.12,19,20 A preclinical study that evaluated the feasibility of using the ZP patch system to deliver recombinant human growth hormone (ZP-hGH) has also been published.11
Intranasal inhalation is also being investigated as an alternate route of glucagon administration. A recent randomized, crossover, non-inferiority study evaluated the efficacy and safety of a novel intranasal glucagon delivery system (Locemia Solutions, Montreal, Quebec) in comparison with standard intramuscular injection of glucagon for the treatment of insulin-induced hypoglycemia in adults with type 1 diabetes.21
A more user-friendly delivery system for glucagon than is currently used could potentially reduce the use of emergency services, hospitalization, and product wastage (a consequence of glucagon for injection being improperly mixed).
The preclinical study of the ZP-hGH patch (for recombinant human growth hormone delivery) reported that stability experiments conducted on the patch support that the ZP-hGH patch in the sealed pouch remained stable at 40oC for up to six months with no significant changes.11 If the ZP-Glucagon patch has a similar stability, this could make it easier for individuals at risk for severe hypoglycemic attacks to carry the ZP-Glucagon patch with them. In comparison, currently available glucagon for injection must be stored at controlled room temperature (15oC to 30oC) before reconstitution, and unused portions must be discarded after reconstitution.6
The microneedle technology used in the ZP-patch system could have applicability to a wide range of therapeutic compounds (e.g., small molecules to proteins, peptides, and vaccines) that cannot be administered using currently available transdermal or oral delivery methods.9 Potential advantages of microneedle technology compared with injections include reduced pain and bleeding, elimination of needle-stick injuries, potential for controlled drug delivery, ability to self-administer, and acceptance by children and individuals with needle phobia.7 Possible drawbacks of the technology are delayed onset of action, inability to confirm the dose delivered, most likely a higher cost, and the risk of skin irritation or allergic reactions related to the adhesive patch.7
The available evidence for efficacy and safety of the ZP-Glucagon patch is limited as the phase II trial enrolled only a small number of patients and although randomized, the study was designed as an open-label crossover trial. Zosano Pharma had indicated plans to initiate a phase III trial in 2016; however, we found no information on this trial.14
As currently available exogenous glucagon requires reconstitution immediately before injection, the ZP-Glucagon patch has the potential to simplify the administration of glucagon and the treatment of severe hypoglycemia. This may be especially beneficial in an emergency situation if the individual is unconscious and caregivers or bystanders are unfamiliar with how to prepare glucagon for injection or how to administer a subcutaneous or intramuscular injection.
Methods — Literature Search Strategy
A limited literature search was conducted using the following bibliographic databases: PubMed, MEDLINE, Embase, and the Cochrane Library. Grey literature was identified by searching relevant sections of the Grey Matters checklist (https://www.cadth.ca/grey-matters). No methodological filters were applied. The search was limited to English-language documents published between January 1, 2012 and January 25, 2017. Conference abstracts published between January 1, 2015 and January 25, 2017 were included in the search results. Regular alerts were used and the search updated until project completion; only citations retrieved before February 10 were incorporated into the analysis.
- Canadian Diabetes Association Clinical Practice Guidelines Expert Committee, Clayton D, Woo V, Yale JF. Hypoglycemia. Can J Diabetes. 2013 Apr;37 Suppl 1:S69-S71.
- Iqbal A, Heller S. Managing hypoglycaemia. Best Pract Res Clin Endocrinol Metab. 2016 Jun;30(3):413-30.
- International Hypoglycaemia Study Group. Minimizing hypoglycemia in diabetes. Diabetes Care. 2015 Aug;38(8):1583-91.
- Cryer PE. Minireview: Glucagon in the pathogenesis of hypoglycemia and hyperglycemia in diabetes. Endocrinology [Internet]. 2012 Mar [cited 2017 Feb 6];153(3):1039-48. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281526
- Marroqui L, onso-Magdalena P, Merino B, Fuentes E, Nadal A, Quesada I. Nutrient regulation of glucagon secretion: involvement in metabolism and diabetes. Nutr Res Rev. 2014 Jun;27(1):48-62.
- Glucagon (glucagon for injection, rDNA origin): 1 mg glucagon per vial [product monograph]. Toronto: Eli Lilly Canada Inc.; 2012 Jul 9.
- Caffarel-Salvador E, Donnelly RF. Transdermal drug delivery mediated by microneedle arrays: Innovations and barriers to success. Curr Pharm Des. 2016;22(9):1105-17.
- Katikaneni S. Transdermal delivery of biopharmaceuticals: dream or reality? Ther Deliv. 2015;6(9):1109-16.
- Rejinold NS, Shin JH, Seok HY, Kim YC. Biomedical applications of microneedles in therapeutics: recent advancements and implications in drug delivery. Expert Opin Drug Deliv. 2016;13(1):109-31.
- Watkinson AC, Kearney MC, Quinn HL, Courtenay AJ, Donnelly RF. Future of the transdermal drug delivery market--have we barely touched the surface? Expert Opin Drug Deliv. 2016;13(4):523-32.
- Ameri M, Kadkhodayan M, Nguyen J, Bravo JA, Su R, Chan K, et al. Human growth hormone delivery with a microneedle transdermal system: Preclinical formulation, stability, delivery and PK of therapeutically relevant doses. Pharmaceutics [Internet]. 2014 [cited 2017 Jan 28];6(2):220-34. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4085596
- Corporate presentation [Internet]. Fremont (CA): Zosano Pharma; 2015. [cited 2017 Feb 15]. Available from: https://www.sec.gov/Archives/edgar/data/1587221/000119312515217189/d939689dex991.htm
- Transdermal drug delivery ready for relief? Ready. Set. Apply [video on the Internet]. Fremont (CA): Zosano Pharma; 2017. [cited 2017 Mar 14]. Available from: http://www.zosanopharma.com/technology/
- Zosano Pharma announces positive phase 2 results for its ZP-Glucagon patch program for treatment of severe hypoglycemia [Internet]. Fremont (CA): Zosano Pharma; 2015 Oct 13. [cited 2017 Feb 15]. Available from: http://ir.zosanopharma.com/releasedetail.cfm?ReleaseID=936338
- Canadian Diabetes Association Clinical Practice Guidelines Expert Committee, Imran SA, Rabasa-Lhoret R, Ross S. Targets for glycemic control. Can J Diabetes. 2013 Apr;37 Suppl 1:S31-S34.
- Kellerman D. A phase 2 active-controlled trial evaluating the effectiveness of two dose levels of Zp-Glucagon patch for reversing hypoglycemia in diabetic subjects [Internet]. Abstract presented at: AAPS Annual Meeting and Exposition. 2016 Nov 13-17; Denver, CO. [cited 2017 Feb 15]. Available from: http://abstracts.aaps.org/Verify/AAPS2016/Invited/Submission/out/AAPS2016-000148.pdf
- Zosano Pharma Inc. Safety and efficacy of ZP-Glucagon to injectable glucagon for hypoglycemia. 2015 May 21 [cited 2017 Feb 15; Last updated: 2016 Aug 14]. In: ClinicalTrials.gov [Internet]. Bethesda (MD): U.S. National Library of Medicine; 2000 - . Available from: https://clinicaltrials.gov/ct2/show/NCT02459938 Identifier: NCT02459938.
- Zosano Pharma's pipeline [Internet]. Fremont (CA): Zosano Pharma; 2016. [cited 2017 Feb 15]. Available from: http://www.zosanopharma.com/technology/pipeline/
- Zosano Pharma Inc. Safety and efficacy of ZP-Zolmitriptan intracutaneous microneedle systems for the acute treatment of migraine (Zotrip). 2016 Apr 14 [cited 2017 Feb 16; Last updated: 2017 Jan 6]. In: ClinicalTrials.gov [Internet]. Bethesda (MD): U.S. National Library of Medicine; 2000 - . Available from: https://clinicaltrials.gov/ct2/show/NCT02745392 Identifier: NCT02745392.
- Zosano Pharma Inc. A study to determine the patient preference between Zosano Pharma parathyroid hormone (ZP-PTH) patch and Forteo pen. 2015 Jun 16 [cited 2017 Feb 16; Last updated: 2016 Aug 21]. In: ClinicalTrials.gov [Internet]. Bethesda (MD): U.S. National Library of Medicine; 2000 - . Available from: https://clinicaltrials.gov/ct2/show/NCT02478879 Identifier: NCT02478879.
- Rickels MR, Ruedy KJ, Foster NC, Piche CA, Dulude H, Sherr JL, et al. Intranasal glucagon for treatment of insulin-induced hypoglycemia in adults with Type 1 Diabetes: A randomized crossover noninferiority study. Diabetes Care [Internet]. 2016 Feb [cited 2017 Feb 6];39(2):264-70. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4722945
About This Document
Author: Eugenia Palylyk-Colwell, Caitlyn Ford
Cite as: A transdermal glucagon patch for severe hypoglycemia. Ottawa: CADTH; 2017 Jun. (CADTH issues in emerging health technologies; issue 159)
Acknowledgments: CADTH thanks the external reviewers who kindly provided comments on an earlier draft of this bulletin.
ISSN: 1488-6324 (online)
Disclaimer: The information in this document is intended to help Canadian health care decision-makers, health care professionals, health systems leaders, and policymakers make well-informed decisions and thereby improve the quality of health care services. While patients and others may access this document, the document is made available for informational purposes only and no representations or warranties are made with respect to its fitness for any particular purpose. The information in this document should not be used as a substitute for professional medical advice or as a substitute for the application of clinical judgment in respect of the care of a particular patient or other professional judgment in any decision-making process. The Canadian Agency for Drugs and Technologies in Health (CADTH) does not endorse any information, drugs, therapies, treatments, products, processes, or services.
While CADTH has taken care to ensure that the information prepared by it in this document is accurate, complete, and up-to-date as at the applicable date the material was first published by CADTH, CADTH does not make any guarantees to that effect. CADTH does not guarantee and is not responsible for the quality, currency, propriety, accuracy, or reasonableness of any statements, information, or conclusions contained in any third-party materials used in preparing this document. The views and opinions of third parties published in this document do not necessarily state or reflect those of CADTH.
CADTH is not responsible for any errors, omissions, injury, loss, or damage arising from or relating to the use (or misuse) of any information, statements, or conclusions contained in or implied by the contents of this document or any of the source materials.
This document may contain links to third-party websites. CADTH does not have control over the content of such sites. Use of third-party sites is governed by the third-party website owners’ own terms and conditions set out for such sites. CADTH does not make any guarantee with respect to any information contained on such third-party sites and CADTH is not responsible for any injury, loss, or damage suffered as a result of using such third-party sites. CADTH has no responsibility for the collection, use, and disclosure of personal information by third-party sites.
Subject to the aforementioned limitations, the views expressed herein are those of CADTH and do not necessarily represent the views of Canada’s federal, provincial, or territorial governments.
This document is prepared and intended for use in the context of the Canadian health care system. The use of this document outside of Canada is done so at the user’s own risk.
This disclaimer and any questions or matters of any nature arising from or relating to the content or use (or misuse) of this document will be governed by and interpreted in accordance with the laws of the Province of Ontario and the laws of Canada applicable therein, and all proceedings shall be subject to the exclusive jurisdiction of the courts of the Province of Ontario, Canada.
The copyright and other intellectual property rights in this document are owned by CADTH and its licensors. These rights are protected by the Canadian Copyright Act and other national and international laws and agreements. You are permitted to make copies of this document for non-commercial purposes only, provided it is not modified when reproduced and appropriate credit is given to CADTH and its licensors.
About CADTH: CADTH is an independent, not-for-profit organization responsible for providing Canada’s health care decision-makers with objective evidence to help
make informed decisions about the optimal use of drugs, medical devices, diagnostics, and procedures in our health care system.
Funding: CADTH receives funding from Canada’s federal, provincial, and territorial governments, with the exception of Quebec.