Radnostix (INIS) drops DUF6 plant sale and outlines costs of capsule recall

Rhea-AI Filing Summary

Radnostix, Inc. terminated its Asset Purchase Agreement with American Fuel Resources for the sale of its depleted uranium deconversion and fluorine extraction plant. The decision followed AFR’s request for a one-year extension after it could not pay the remaining $12,450,000 purchase price by the March 31, 2026 outside date.

AFR had previously made a non‑refundable $50,000 prepayment and twelve non‑refundable NRC extension fee payments totaling $120,000. With termination, Radnostix retains ownership of the DUF6 plant, which it believes has appreciated in value, and plans to evaluate future options for these assets.

The company also initiated a voluntary recall of specific lots of its Dibasic Sodium Phosphate Capsules shipped between August 19, 2024 and February 17, 2026. It expects a one‑time charge of about $75,000 in fourth‑quarter 2025 for inventory write‑offs and about $50,000 in first‑quarter 2026 for customer refunds, plus roughly $75,000 for new capsule inventory and an estimated $25,000 to $75,000 per week in lost revenue, which it believes will not extend beyond the second quarter.

Insights

Healthcare & Nuclear Materials Analyst

Radnostix loses expected DUF6 sale proceeds but keeps the asset; recall costs appear significant yet time-limited.

Radnostix ended its DUF6 plant sale after AFR could not meet the $12,450,000 closing payment deadline. The company keeps a specialized asset it believes has gained value, while forfeiting previously anticipated cash proceeds and associated balance sheet improvements described in earlier disclosures.

The voluntary recall of Dibasic Sodium Phosphate Capsules brings direct charges of roughly $125,000 plus about $75,000 in new inventory and an estimated $25,000–$75,000 per week in lost revenue. Management expects the financial impact to be confined mainly to the first and second quarters, and notes core Generic Sodium Iodide I‑131 supply remains unaffected.

8-K Event Classification

3 items: 1.02, 8.01, 9.01

3 items

Item 1.02 Termination of a Material Definitive Agreement Business

A significant contract was terminated, which may affect business operations or revenue.

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Understanding 8-K Material Events →

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE

THE SECURITIES EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported):

March 11, 2026

RADNOSTIX, INC.

(Exact name of registrant as specified in its charter)

Texas		0-22923		74-2763837
(State or other jurisdiction of incorporation or organization)		(Commission File Number)		(I.R.S. Employer Identification No.)

4137 Commerce Circle

Idaho Falls, ID 83401

(Address of Principal Executive Offices) (Zip Code)

208-524-5300 

Registrant’s telephone number, including area code: (505) 438-2576

N/A

Former name or former address, if changed since last report

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: None

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.02 Termination of a Material Agreement.

On March 16, 2026, Radnostix, Inc. (formerly International Isotopes, Inc., “RNX” or the “Company”), announced a mutual termination on March 11, 2026 of an Asset Purchase Agreement (the “APA”) dated February 8, 2024 that was entered into between RNX and its wholly-owned subsidiary International Isotopes Fluorine Products, Inc. (together with RNX, the “Seller”) and American Fuel Resources, LLC (“AFR”). The APA set forth the terms pursuant to which the Company agreed to sell to AFR all the assets and certain specified liabilities of the Company’s depleted uranium deconversion and fluorine extraction plant (the “DUF6 Plant”), subject to the terms and conditions set forth in the APA. The APA provided that it may be terminated, among other things, upon mutual written consent by the parties to the APA.

AFR contacted the Company requesting a 1-year extension due to AFR being unable to make payment of the balance of the purchase price by March 31, 2026 (the “Outside Date”) in order to meet the Condition to Seller’s Obligations (as defined and set forth in Section 6.02(c) of the APA). The parties were in the final stages of the U.S. Nuclear Regulatory Commission (the “NRC”) consent process to receive NRC consent to transfer; however, the parties mutually agreed to withdraw the application and terminate the APA.

AFR already made a non-refundable $50,000 Prepayment and twelve non-refundable NRC Extension Fee payments totaling $120,000 and was to pay an additional $12,450,000 at closing (as such capitalized terms are defined in the APA). Closing of the transaction was subject to certain closing conditions, including (i) transfer of the NRC license related to the DUF6 Plant (the “NRC License Transfer”) and (ii) transfer of Purchased Assets (as defined in the APA), which includes licenses, patents, agreements, and other records of the DUF6 Plant.

The Company decided it was in the best interest of the shareholders to regain control of the assets as we believe they have appreciated in value since entering the APA and the Company had low confidence that AFR would be able to secure funding to close the deal by the requested extension date. The Company will evaluate all possible options for the DUF6 Plant and related assets.

The Company previously disclosed in its Quarterly Report on Form 10-Q for the quarter ending September 30, 2025, the expected financial and operational impacts associated with the APA. Because the agreement has been terminated, none of the previously disclosed anticipated results of the APA will occur. Specifically, the Company will not receive the balance of the purchase price, will not recognize a gain on the sale of assets, will not use proceeds to repay various long-term notes, and will not realize the previously disclosed anticipated impacts on cash, assets, liabilities, operating costs, or future financing flexibility.

Item 8.01 Other Events.

On February 19, 2026, the Company, which is a manufacturer of its Generic Sodium Iodide I-131, discovered during an internal audit that specific lots of our Dibasic Sodium Phosphate Capsules that may be provided with our Generic Sodium Iodide I-131 kits manufactured between 2022 and 2025 may be out of specification due to final capsule weight. The Company initiated a voluntary recall of specific lots of our Dibasic Sodium Phosphate Capsules shipped between August 19, 2024 to February 17, 2026. The Company has notified affected pharmacies, clinics, and veterinarians of the voluntary recall. The recall is being conducted with the knowledge of the U.S. Food and Drug Administration (the “FDA”). This disclosure on a Form 8-K is voluntary and not because a materiality threshold has been met to date.

While it is too early to ascertain the total cost and materiality of the voluntary recall, the Company expects to record a one-time charge of approximately $75,000 to its 4th quarter 2025 results for cost of products related to write-off of impacted Company capsule inventory and a one-time charge of approximately $50,000 to its first quarter cost of products related to refunds to certain customers. The Company will likely incur additional costs related to the recall in 2026 which are currently estimated to be approximately $75,000 in new capsule inventory and $25,000 to $75,000 a week in lost revenue. The Company believes the impact from the recall will not extend beyond the 2nd quarter. The Company does not believe that its first quarter business was impacted by the recall beyond the impacts addressed above. The Company continues to provide Generic Sodium Iodide I-131, which was not impacted, and does not anticipate the recall will materially impact its ability to provide Generic Sodium Iodide I-131 to its practitioner partners or the ability of practitioners to service patients. More details on the potential financial impact of this event will be provided when the Company reports its fourth quarter results, or sooner if we deem material.

Cautionary Note Regarding Forward Looking Statements

This Current Report on Form 8-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the Company’s current expected financial impact from the termination of the APA, the estimated value of the DUF6 Plant and related assets, the voluntary recall of product and the financial impact of the recall. Actual results could differ materially from management's expectations, plans or projections. Certain risks and uncertainties that could cause our actual results to differ significantly from management’s expectations are described in the risk factors set forth in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024 filed with the Securities and Exchange Commission (SEC) on March 3, 2025 and in the other reports we file with the SEC. These factors describe some but not all of the factors that could cause actual results to differ significantly from management’s expectations. We undertake no obligation to update any forward-looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events. Readers are urged, however, to review the risks and other factors set forth in the reports that we file from time to time with the SEC.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number		Description
99.1		Press Release regarding Mutual Termination of Asset Purchase Agreement dated March 16, 2026.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: March 16, 2026	INTERNATIONAL ISOTOPES INC.
	By:	/s/ Shahe Bagerdjian
	Name:	Shahe Bagerdjian
	Title:	President and Chief Executive Officer

Exhibit 99.1

1.208.524.5300
4137 Commerce Circle Idaho Falls, ID, USA 83401 Radnostix.com

For Immediate Release
March 16^th, 2026

Mutual Termination of the Asset Purchase Agreement related to the Radnostix DUF6 Assets

IDAHO FALLS, IDAHO, March 16^th, 2026. Radnostix, Inc. (formerly International Isotopes, Inc., “RNX” or the “Company”), announced a mutual termination of an Asset Purchase Agreement (the “APA”) dated February 8, 2024 entered into between RNX and its wholly owned subsidiary International Isotopes Fluorine Products, Inc. (together with RNX, the “Seller”) and American Fuel Resources, LLC (“AFR”). The APA set forth the terms pursuant to which the Company agreed to sell to AFR all the assets and certain specified liabilities of the Company’s depleted uranium deconversion and fluorine extraction plant (the “DUF6 Plant”), subject to the terms and conditions set forth in the APA. The APA provided that it may be terminated, among other things, upon mutual written consent by the parties to the APA.

AFR contacted the Company requesting a 1-year extension due to AFR being unable to make the payments of the final purchase price by March 31, 2026 (the “Outside Date”) in order to meet the Condition to Seller’s Obligations (as defined and set forth in Section 6.02(c) of the APA) for. Although the parties were in the final stages of the NRC consent process and were on the cusp of receiving U.S. Nuclear Regulatory Commission (the “NRC”) consent to transfer, the parties agreed to withdraw the application and terminate the Agreement.

“With the resurgence in large scale nuclear energy projects, including several domestic uranium enrichment initiatives, we believe these assets have meaningful value to our shareholders and the fuel cycle industry as a whole.,” Shahe Bagerdjian, CEO of Radnostix, Inc, adding, “I want to thank AFR for their persistence and efforts in trying to close this deal and their transparency at the end. We look forward to exploring all our options for the DUF6 assets over the coming months.”

AFR already made a non-refundable $50,000 Prepayment and twelve non-refundable NRC Extension Fee payments totaling $120,000 and was to pay an additional $12,450,000 at closing. Closing of the transaction was subject to certain closing conditions, including (i) transfer of the NRC license related to the DUF6 Plant (the “NRC License Transfer”) and (ii) transfer of Purchased Assets (as defined in the APA), which includes licenses, patents, agreements, and other records of the DUF6 Plant.

The Company decided it was in the best interest of the shareholders to regain control of the assets as we believe they have appreciated in value since entering the APA and the Company had low confidence that AFR would be able to secure funding to close the deal by the requested extension date. The Company will evaluate all possible options for the DUF6 Assets.

The Company previously disclosed in its Quarterly Report on Form 10-Q for the quarter ending September 30, 2025, the expected financial and operational impacts associated with the APA. Because the agreement has been terminated, none of the previously disclosed anticipated results of the APA will occur. Specifically, the Company will not receive the previously disclosed consideration, will not recognize a gain on the sale of assets, will not use proceeds to repay various long-term notes, and will not realize the previously disclosed anticipated impacts on cash, assets, liabilities, operating costs, or future financing flexibility.

About Radnostix (formerly International Isotopes Inc.): Radnostix, Inc. (formerly International Isotopes Inc.) (INIS), established in 1995, with its headquarters in Idaho Falls, ID, USA, manufactures a wide range of radioisotope-focused products. Radnostix manufactures and supplies generic sodium iodide I-131 radio-pharmaceutical drug product for hyperthyroidism and thyroid cancer. Radnostix provides contract manufacturing of various drug products as well as radioisotope API supply for 3rd party theranostics clients. Radnostix manufactures and distributes a complete line of calibration and reference standards for nuclear pharmacies and SPECT/PET imaging systems as well as industrial calibration standards under its RadQual brand. For more information, visit www.radnostix.com.

Radnostix, Inc. (formerly International Isotopes Inc.) Safe Harbor Statement:
Certain statements in this press release are "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, including but not limited to, statements regarding the Company’s current expected financial impact from the termination of the APA, the estimated value of the DUF6 Plant and related assets, statements with respect to the Company's future growth expectations. Information contained in such forward-looking statements is based on current expectations and is subject to change. These statements involve a number of risks, uncertainties and other factors that could cause actual results, performance, or achievements of Radnostix, Inc. to be materially different from any future results, performance or achievements of the Company expressed or implied by these forward-looking statements. Other factors, which could materially affect such forward-looking statements, can be found in the Company's filings with the Securities and Exchange Commission at www.sec.gov, including its Annual Report on Form 10-K for the year ended December 31, 2024. Investors, potential investors, and other readers are urged to consider these factors carefully in evaluating the forward-looking statements and are cautioned not to place undue reliance on such forward-looking statements. The forward-looking statements made herein are only made as of the date of this press release and Radnostix, Inc. and the Company undertake no obligation to publicly update such forward-looking statements to reflect subsequent events or circumstances.

Radnostix Contact: 
ir@intisoid.com
radnostix.com

FAQ

What did Radnostix (INIS) announce about its DUF6 plant sale agreement?

Radnostix announced mutual termination of its Asset Purchase Agreement to sell its DUF6 plant to American Fuel Resources. AFR could not pay the remaining $12,450,000 by the March 31, 2026 outside date, so the parties withdrew the NRC transfer application and ended the deal.

How much was American Fuel Resources expected to pay Radnostix (INIS) at closing?

American Fuel Resources was to pay an additional $12,450,000 at closing under the Asset Purchase Agreement. It had already made a non‑refundable $50,000 prepayment and twelve non‑refundable NRC extension fee payments totaling $120,000, but could not meet the final payment deadline.

Why did Radnostix (INIS) decide to terminate the DUF6 Asset Purchase Agreement?

Radnostix stated it was in shareholders’ best interest to regain control of the DUF6 assets. The company believes these assets have appreciated in value and had low confidence AFR could secure funding to close the transaction by the requested one‑year extension to the March 31, 2026 outside date.

What product recall did Radnostix (INIS) disclose in this 8-K filing?

Radnostix disclosed a voluntary recall of specific lots of its Dibasic Sodium Phosphate Capsules provided with Generic Sodium Iodide I‑131 kits. An internal audit found some capsule lots manufactured between 2022 and 2025 may be out of specification on final capsule weight, prompting notification of affected pharmacies, clinics, and veterinarians.

What are the estimated financial impacts of Radnostix’s product recall?

Radnostix expects a one‑time $75,000 charge in fourth‑quarter 2025 for inventory write‑offs and about $50,000 in first‑quarter 2026 for customer refunds. It also anticipates about $75,000 for new capsule inventory and roughly $25,000–$75,000 per week in lost revenue during the recall period.

Will Radnostix’s Generic Sodium Iodide I-131 supply be affected by the recall?

Radnostix stated that its Generic Sodium Iodide I‑131 product itself was not impacted by the recall. The company continues to supply this drug and does not expect the capsule recall to materially affect its ability to serve practitioner partners or their ability to treat patients.

How does the DUF6 deal termination affect Radnostix’s previously disclosed plans?

Because the Asset Purchase Agreement is terminated, previously disclosed expectations tied to the sale will not occur. Radnostix will not receive the remaining purchase price, recognize a gain on asset sale, repay various long‑term notes with sale proceeds, or realize the earlier anticipated effects on cash, assets, liabilities, operating costs, or financing flexibility.

Filing Exhibits & Attachments

5 documents

Press Releases

• EX-99.1 EXHIBIT 99.1 10.7 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.5 KB
• EX-101 XBRL TAXONOMY EXTENSION DEFINITION LINKBASE 10.1 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 13.5 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 10.1 KB