Join us in supporting the Citizens' Petition

Currently, DTPA is not on the market in the USA.  This defies reason; it is available everywhere else in the world but not in the USA.  I have filed a petition: Citizen Petition FDA-2026-P-9677.
 
DTPA is the best chelator to treat Gd, Lead, Cadmium, and Inorganic mercury toxicity.
 
It is imperative that all patients with GDD and all practitioners who see them write a letter of support for this petition.

Please sign this petition and share it with your family and friends to join us in this urgent and most important matter. 
 
Also, I am asking each of you who can to go to the  Regulations.gov website and support the official FDA Petition.  This is important because the FDA is not required to read this petition on Change.org, but they are required to read the results at Regulations.gov. 

Both of these petitions are extremely important for this cause.  There are several steps and I have listed them below to make the process easier. 

The FDA has now formally assigned the petition the following docket number:
FDA-2026-P-9677
 
If you support the petition, I would greatly appreciate your submitting a brief letter or comment to the FDA. Your submission will become part of the official public record for this Citizen Petition. 

The FDA/Regulations.gov submission process is not particularly intuitive, so I have provided step-by-step instructions below.

1. Go to  Regulations.gov. website
 
2. Search for the docket number exactly as follows:  FDA-2026-P-9677
 Enter this number into the search box and select Search.  
 
3. Open the docket for FDA-2026-P-9677.   
 The docket should display the Citizen Petition and the associated documents.

4. Select the “Documents” tab if necessary.
 Scroll near the bottom of the list and click. Locate the Citizen Petition or document associated with this docket that has an active Comment button. 
 
5. Select “Comment.”                                                                                                                                                                                                          You may comment or upload a letter in the comment box.
 
6. In the comment box, write a short statement supporting the petition.                                                                                    “I support Citizen Petition FDA-2026-P-9677. Please see my attached letter of support.” Important!

7. You may also attach a separate signed letter. Optional.

9. Review the submission carefully.
 Before submitting, verify that the docket number shown is:  FDA-2026-P-9677
 
10. Request the email confirmation.   Regulations.gov provides an option to receive an email confirmation. I strongly recommend selecting this option.
 
11. Select “Submit Comment.”
 After submission, Regulations.gov should provide a tracking number.

 

The Official Petition submitted to the FDA is below.  

Citizen Petition  FDA-2026-P-9677

Date: August 20, 2026

The undersigned submits this petition under section 564A(b) and other applicable provisions of the Federal Food, Drug, and Cosmetic Act to request the Commissioner of Food and Drugs to take the administrative actions set forth below to preserve continuous United States availability of pentetate calcium trisodium (CaDTPA) and pentetate zinc trisodium (Zn-DTPA), FDA-approved medical countermeasures for internal contamination with plutonium, americium, or curium. 

A. Action Requested

1. Expedited preservation of existing Hameln product. FDA should work expeditiously with Hameln 
Pharma GmbH on any scientifically supportable manufacturer-initiated extension of expiration dating for existing Ca-DTPA and Zn-DTPA lots. Such extension should remain dependent on acceptable stability data and continued conformity with applicable specifications for identity, strength, quality, purity, sterility, and product integrity. FDA should not allow otherwise suitable product to become unavailable solely because an originally assigned expiration date has elapsed when adequate data support continued stability. [8] 

2. Use of applicable medical-countermeasure expiration authorities. For eligible stockpiled DTPA 
medical countermeasures, FDA should consider all legally applicable mechanisms for expiration-date 
extension, including section 564A(b) of the Federal Food, Drug, and Cosmetic Act, the federal Shelf-Life 
Extension Program where applicable, and other established FDA mechanisms. FDA has recognized that 
properly stored medical countermeasures may remain stable beyond their labeled expiration dates when 
supported by appropriate scientific evaluation. [8] 

3. Facilitation of continued Hameln marketing in the United States. FDA should work with Hameln to 
identify and minimize avoidable regulatory burdens associated with continued U.S. marketing of these very 
low-volume but strategically important products. The petitioner recognizes that FDA does not set drug prices and cannot compel a manufacturer to continue production. The request is therefore for prompt regulatory engagement and for coordination with agencies that possess procurement and preparedness authorities. [8,16] 

4. Drug-shortage and medical-countermeasure coordination. FDA should treat actual or impending 
unavailability of Ca-DTPA and Zn-DTPA as a potential national drug-supply and medical-countermeasure problem and coordinate review through the Center for Drug Evaluation and Research, including the Drug 
Shortage Staff and the Counter-Terrorism and Emergency Coordination Staff, as appropriate. [17,18]

5. Interagency action to make continued supply economically sustainable. FDA should coordinate with 
the Administration for Strategic Preparedness and Response, the Biomedical Advanced Research and 
Development Authority, the Strategic National Stockpile, the Department of Defense, and other appropriate federal partners to consider procurement, stockpile replenishment, long-term contracting, vendor-managed inventory, or other lawful mechanisms capable of sustaining a reliable U.S. supply. Historical federal procurement of DTPA demonstrates that government purchasing has previously been used to address the limited-commercial-market problem inherent to radiological medical countermeasures. [5-7] 

6. Long-term supply resilience without displacement of Hameln. Without diminishing Hameln's role, 
FDA and federal preparedness partners should consider establishing regulatory readiness for at least one 
additional qualified source of Ca-DTPA and Zn-DTPA. The purpose would be redundancy and continuity of 
supply, not replacement of Hameln. Any additional product should meet applicable FDA requirements before routine U.S. marketing. [9,10,13-15] 

7. Expedited consideration. Because DTPA must be available before a radiological or nuclear incident 
occurs, the petitioner requests expedited consideration of the supply-preservation aspects of this petition and early interagency engagement rather than waiting for an emergency to reveal a preventable supply gap. 

 

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B. Statement of Grounds
The immediate objective of this petition is to preserve the existing FDA-approved Hameln supply, including 
prompt consideration of scientifically supported expiration-date extension for existing product and practical regulatory measures that facilitate continued U.S. marketing. The longer-term objective is to establish a durable federal strategy that makes continued DTPA availability economically sustainable and reduces single-source vulnerability. The petition does not seek to replace Hameln. Rather, it seeks to preserve Hameln as the principal FDA-approved supplier while encouraging sufficient redundancy for a nationalsecurity medical countermeasure.

1. Ca-DTPA and Zn-DTPA are FDA-approved radiological and nuclear medical countermeasures. 
FDA approved Ca-DTPA and Zn-DTPA on August 11, 2004, for treatment of individuals with known or 
suspected internal contamination with plutonium, americium, or curium to increase elimination of these 
radionuclides. FDA described the approvals as part of its effort to protect the public from nuclear accidents 
and terrorist threats. FDA also states that Ca-DTPA is more effective than Zn-DTPA during the first 24 hours after internal contamination, after which the two agents are similarly effective. [2,3]

2. Loss of U.S. DTPA availability would create a preparedness vulnerability. The routine commercial 
market for DTPA is necessarily small because large-scale internal contamination with plutonium, americium, or curium is uncommon. That small market does not imply low strategic value. It creates the opposite problem: a pharmaceutical may be commercially unattractive during ordinary times while being 
indispensable in a radiological or nuclear emergency. A medical countermeasure cannot be manufactured, 
approved, distributed, and deployed after an emergency with the speed required for optimal treatment. 
Continuous availability is therefore itself an element of preparedness. [2-6] 

3. The United States has previously procured substantial DTPA supplies for national preparedness. 
Federal preparedness programs have previously acquired Ca-DTPA and Zn-DTPA for the Strategic National 
Stockpile under Project BioShield. A Congressional Research Service report documented procurement of 
approximately 395,000 doses of Ca-DTPA and 80,000 doses of Zn-DTPA, for a total of approximately 
475,000 doses. Earlier HHS planning had recommended acquisition of approximately 450,000 DTPA doses. [5,6] This history establishes that federal procurement of DTPA is neither speculative nor novel; it is an 
established component of U.S. radiological preparedness.

4. Federal policy has previously recognized long shelf life for properly stored DTPA. A 2010 
Department of Defense policy concerning stockpiled Ca-DTPA and Zn-DTPA stated that the acquired 
products had a 10-year shelf life from manufacture when stored and transported under labeled conditions. 
That policy also contemplated evaluation of Shelf-Life Extension Program eligibility. [7] The petitioner does not rely on this history as proof that any specific current Hameln lot remains usable. It does demonstrate that DTPA can have substantial long-term stability and that preservation of stockpiled DTPA has previously been a federal preparedness consideration.

5. FDA already has established pathways for scientifically justified expiration-date extension. FDA 
currently recognizes several mechanisms through which drug expiration dating may be extended when 
supported by acceptable scientific data. These include manufacturer-initiated extensions based on stability studies; the federal Shelf-Life Extension Program; and, for eligible stockpiled medical countermeasures, 
expiration-date extension authority under section 564A(b) of the Federal Food, Drug, and Cosmetic Act. 
FDA states that expiration dates can create significant stockpiling challenges and that some properly stored products remain stable beyond labeled expiration when demonstrated by testing. [8] The present petition therefore asks FDA to apply established science and existing regulatory mechanisms, not to relax drugquality standards.

6. The current U.S. commercial situation warrants prompt attention. Current DailyMed labeling records 
for Hameln Ca-DTPA (NDA 021749) and Zn-DTPA (NDA 021751) list a marketing end date of May 31,

 

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2026. [11,12] The petitioner further understands that existing U.S. product has reached or is reaching labeled expiration and that Hameln is pursuing an extension of expiration dating. Routine commercial access to DTPA in the United States is presently unavailable or severely constrained. These circumstances create an avoidable interval in which an FDA-approved radiological medical countermeasure may be inaccessible to U.S. clinicians despite continuing availability of DTPA products abroad.

7. Preservation of Hameln should be the immediate priority. Hameln is the sponsor of the FDA-approved
U.S. Ca-DTPA and Zn-DTPA products. [2,11,12] The petitioner's primary request is therefore to preserve 
Hameln's continued participation in the U.S. market. Nothing in this petition should be interpreted as 
criticism of Hameln or as a request that FDA displace the company. To the contrary, the petition seeks to 
make continued U.S. supply practical for Hameln and to avoid a situation in which the economics of a very 
small routine market result in loss of a strategically important drug.

8. Continued international manufacture demonstrates that parenteral DTPA remains technically and 
commercially viable. HEYL Chemisch-pharmazeutische Fabrik GmbH & Co. KG currently lists 
Ditripentat-Heyl, a calcium trisodium pentetate solution for intravenous injection or infusion, and a ZnDTPA product. Ditripentat-Heyl contains 1,000 mg Ca-DTPA in 5 mL and is indicated in Germany for 
decorporation of transuranium radionuclides. [13] A 2024 Belgian governmental decision stated that the 
HEYL Ca-DTPA and Zn-DTPA products are authorized in Germany and authorized their importation, 
distribution, purchase, dispensing, and administration in Belgium for radiological preparedness. [14] These 
products are cited as evidence of continuing international manufacture and potential supply redundancy, not as products that may be routinely marketed in the United States without FDA authorization. 

9. FDA has previously considered HEYL petitions concerning the Hameln DTPA products. In 2010, 
HEYL filed Citizen Petitions asking FDA to determine whether Hameln Ca-DTPA and Zn-DTPA had been 
withdrawn for reasons of safety or effectiveness. In 2011, FDA determined that neither product had been 
withdrawn for safety or effectiveness reasons and stated that abbreviated new drug applications referencing the products could be approved if all applicable legal and regulatory requirements were met. [9,10] This history is important because it shows that FDA has previously considered the regulatory pathway for additional DTPA sources. It should not be interpreted as a request to replace Hameln; rather, it supports longterm planning for redundancy if a second qualified supplier seeks U.S. approval. 

10. A single-source national-security medical countermeasure creates unnecessary risk. For an ordinary 
low-volume medicine, commercial discontinuation is principally a market-access issue. For a medical 
countermeasure intended for plutonium, americium, and curium contamination following radiological or 
nuclear events, discontinuation also has national-preparedness implications. A resilient strategy should 
preserve the existing FDA-approved Hameln source while creating sufficient regulatory and procurement 
redundancy that the United States is not dependent indefinitely on the commercial economics of a single 
supplier.

11. Countervailing considerations and limitations. The petitioner recognizes several limitations that 
should remain part of FDA's assessment. First, expiration-date extension must be supported by product- and, where necessary, lot-specific stability information; the petition does not ask FDA to authorize use of 
degraded or inadequately characterized material. Second, FDA does not control pharmaceutical pricing and cannot require a manufacturer to make a drug; economic sustainability may therefore require action by 
ASPR, BARDA, the Strategic National Stockpile, Congress, or other federal entities. Third, HEYL's foreign-authorized products are not presently FDA-approved for routine U.S. marketing and should not be treated as interchangeable finished products absent satisfaction of applicable U.S. regulatory requirements. Fourth, FDA-approved DTPA does not treat every radionuclide; the U.S. approvals specifically address internal contamination with plutonium, americium, and curium. [3,8,16] These limitations do not diminish the central concern: the United States should preserve reliable access to the FDA-approved countermeasures for the radionuclides for which they are indicated.

 

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References and Regulatory Authorities

1. 21 CFR §10.30. Citizen petition. Electronic Code of Federal Regulations. Accessed August 20, 2026. 
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-10/subpart-B/section-10.30

2. U.S. Food and Drug Administration. FDA Approves Drugs to Treat Internal Contamination from Radioactive Elements. August 11, 2004. https://www.fda.gov/drugs/bioterrorism-and-drug-preparedness/fda-approves-drugs-treat-internalcontamination-radioactive-elements

3. U.S. Food and Drug Administration. Questions and Answers on Calcium-DTPA and Zinc-DTPA (Updated). 
https://www.fda.gov/drugs/bioterrorism-and-drug-preparedness/questions-and-answers-calcium-dtpa-and-zinc-dtpaupdated

4. U.S. Food and Drug Administration. Calcium DTPA and Zinc DTPA Drug Products-Submitting a New Drug Application. 
Guidance for Industry. August 2004. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/
calcium-dtpa-and-zinc-dtpa-drug-products-submitting-new-drug-application

5. U.S. Department of Health and Human Services. Project BioShield: Annual Report to Congress, July 2004 through July 2006. https://www.medicalcountermeasures.gov/BARDA/documents/bioshieldannualreport.pdf

6. Gottron F. The Project BioShield Act: Issues for the 112th Congress. Congressional Research Service Report R42349.  Updated December 21, 2012. https://www.congress.gov/crs-product/R42349

7. U.S. Department of Defense. HA Policy 10-004: Policy for Department of Defense Stockpile of Pentetate Calcium Trisodium Injection and Pentetate Zinc Trisodium Injection. July 22, 2010.
https://www.health.mil/Reference-Center/Policies/2010/07/22/Policy-for-Department-of-Defense-Stockpile-ofPentetateCalcium-Trisodium-Injection-and-Pentetate-Zin

8. U.S. Food and Drug Administration. Expiration Dating Extension. Medical Countermeasures Initiative. Updated 2026.   https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/expirationdating-extension

9. U.S. Food and Drug Administration. Determination That Pentetate Calcium Trisodium Solution Was Not Withdrawn From  Sale for Reasons of Safety or Effectiveness. Federal Register. 2011;76:51991-51992. Docket FDA-2010-P-0628.

10. U.S. Food and Drug Administration. Determination That Pentetate Zinc Trisodium Solution Was Not Withdrawn From  Sale for Reasons of Safety or Effectiveness. Federal Register. 2011;76:51992. Docket FDA-2010-P-0630.

11. DailyMed. Pentetate Calcium Trisodium Injection, Solution, Concentrate; hameln pharma gmbh. NDA 021749; NDC 70651-001-03. Marketing end date listed as May 31, 2026. https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=bc563e90-10e5-475d-aa84-b0e3d582ae95&type=pdf

12. DailyMed. Pentetate Zinc Trisodium Injection, Solution, Concentrate; hameln pharma gmbh. NDA 021751; NDC 70651-002-03. Marketing end date listed as May 31, 2026. https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=366e7ca9-4fd3-4688-bd83-1f369885e0fc&type=pdf

13.HEYL Chemisch-pharmazeutische Fabrik GmbH & Co. KG. Ditripentat-Heyl (DTPA): Summary of Product Characteristics. https://www.heyl-berlin.de/pharma/poisoning/ditripentat-heyl/?lang=en

14. Belgian Official Gazette. Decision authorizing importation, distribution, purchase, dispensing, and administration of Ditripentat-Heyl and HEYL Zn-DTPA for radiological preparedness. June 10, 2024.

15.HEYL Chemisch-pharmazeutische Fabrik GmbH & Co. KG. Product overview: Ditripentat-Heyl and Zink-Trinatriumpentetat. https://www.heyl-berlin.de/service/productoverview/?lang=en

16. U.S. Food and Drug Administration. Frequently Asked Questions about Drug Shortages. https://www.fda.gov/drugs/drugshortages/frequently-asked-questions-about-drug-shortages

17. U.S. Food and Drug Administration. Drug Shortages / How to Report a Shortage or Supply Issue. 
https://www.fda.gov/drugs/drug-shortages/how-report-shortage-or-supply-issue

18. U.S. Food and Drug Administration. Counter-Terrorism and Emergency Coordination Staff. https://www.fda.gov/aboutfda/cder-offices-and-divisions/counter-terrorism-and-emergency-coordination-staff

19. 21 CFR §25.30. General. Electronic Code of Federal Regulations. Accessed August 20, 2026. 
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-25/subpart-C/section-25.30

20. 21 CFR §25.31. Human drugs and biologics. Electronic Code of Federal Regulations. Accessed August 20, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-25/subpart-C/section-25.31

21. 21 CFR §25.21. Extraordinary circumstances. Electronic Code of Federal Regulations. Accessed August 20, 2026. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-25/subpart-B/section-25.21

 

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C. Environmental Impact
The petitioner claims categorical exclusion for the requested administrative and management actions under 21 CFR §25.30(a) and, to the extent any requested FDA action constitutes action on an NDA, abbreviated application, or supplement that does not increase use of the active moiety, under 21 CFR §25.31(a). [19,20] The petitioner is not aware of extraordinary circumstances indicating that the requested actions may significantly affect the quality of the human environment within the meaning of 21 CFR §25.21. [21] 

D. Economic Impact
Economic impact information will be submitted if requested by the Commissioner following review of this 
petition.

E. Certification
The undersigned certifies that, to the best knowledge and belief of the undersigned, this petition includes all information and views on which the petition relies, and that it includes representative data and information known to the petitioner which are unfavorable to the petition.

Richard C. Semelka, MD

Thank you for your support!