Moleculin Announces Completion of Treatment for the 45 Patients in Pivotal “MIRACLE” Phase 3 AML Trial on Pace for Q1 2026

Rhea-AI Summary

Moleculin (Nasdaq: MBRX) reported that 78% of the target subjects for the first planned interim unblinding of its pivotal Phase 2B/3 MIRACLE trial have consented, up from 60% in November, with consented subjects now across seven countries. The company expects to complete treatment of the first 45 subjects in Q1 2026 and to finish Part A (up to 90 patients) in the first half of 2026. Annamycin (naxtarubicin) holds FDA Fast Track and Orphan Drug designations and composition-of-matter patent protection through 2040 (potential extension to 2045). Enrollment and blinded activity are reported as within expected ranges.

Positive

• 78% consented toward first 45-subject unblinding
• Expect to complete treatment of 45 subjects in Q1 2026
• Part A completion target: up to 90 patients in H1 2026
• FDA Fast Track and Orphan Drug designations
• Composition-of-matter patent protection through 2040

Negative

• 45-subject unblinding not designed for statistical significance
• Early enrollment delays caused by EU bed shortages
• Must recruit remaining 45 subjects to complete Part A

Key Figures

Subjects consented 78% of target First planned interim unblinding cohort for MIRACLE trial as of Dec 3, 2025

First unblinding cohort 45 subjects Part A early efficacy and safety data set in MIRACLE trial

Part A size Up to 90 patients Total enrollment for Phase 2B (Part A) in MIRACLE

Annamycin-treated subjects 30 subjects First unblinding: 190 mg/m2 and 230 mg/m2 plus HiDAC arms combined

Control arm subjects 15 subjects First unblinding: HiDAC plus placebo arm

Annamycin doses 190 mg/m2 and 230 mg/m2 Dose levels tested with HiDAC in MIRACLE Part A

Countries involved 7 countries Current MIRACLE trial consented patient sites

Patent protection horizon 2040–2045 Annamycin composition of matter patent life with extension potential

Market Reality Check

$7.25 Last Close

Volume Volume 814,206 is about 5.68x the 20-day average of 143,243, indicating elevated trading interest ahead of this trial milestone update. high

Technical Shares at $7.25 are trading below the 200-day MA of $17.00 and sit 92.05% under the 52-week high with a buffer of 20.63% above the 52-week low.

Peers on Argus

MBRX is modestly higher while peers show mixed moves: LPTX up 238.84%, KZIA up 3.08%, MBIO up 1.63%, and INTS/SNGX down 7.13% and 2.47%, suggesting today’s action is more stock-specific than a broad biotech move.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 08	Research collaboration	Neutral	+0.1%	New preclinical collaboration to study Annamycin in GBM mouse models.
Nov 26	Investor event	Neutral	-22.0%	Announcement of CEO participation in Virtual Investor Closing Bell Series.
Nov 26	Reverse stock split	Neutral	-22.0%	Implementation of <b>1-for-25</b> reverse stock split to consolidate shares.
Nov 13	Trial enrollment update	Neutral	-6.9%	Reported <b>60%</b> of first <b>45</b> MIRACLE subjects consented toward Q1 2026 data.
Nov 12	Grant-funded research	Neutral	+1.8%	Grant-backed preclinical studies of Annamycin in pancreatic cancer at UNC.

Recent Company History

Over the last few months, Moleculin has focused on advancing Annamycin and supporting programs around it. Key events include a 1-for-25 reverse split and Nasdaq compliance challenges, new grant-funded and collaborative preclinical work in pancreatic and brain cancers, and repeated updates on the pivotal MIRACLE AML trial, including reaching 60% of the first 45 subjects consented. Today’s news continues that MIRACLE enrollment narrative with higher consent levels and clearer timing toward Q1 2026 unblinding and Part A completion in H1 2026.

Regulatory & Risk Context

Active S-3 Shelf Registration 2025-09-19

The company has an active S-3 shelf registration dated 2025-09-19 that remains in effect until 2028-09-19. The filing is noted as not yet effective and shows 0 recorded usages, so no takedowns are reflected in the provided data. Specific dollar capacity is not available in this context.

Market Pulse Summary

This announcement advances the pivotal MIRACLE AML trial by reporting 78% of the first 45 subjects consented and clarifying expectations for Q1 2026 unblinding and completion of up to 90 Part A patients in H1 2026. Prior updates and regulatory filings underline both Annamycin’s Fast Track and Orphan designations and the company’s financial constraints and listing challenges. Investors may watch enrollment pace, upcoming unblinded data, and capital-raising disclosures as key future catalysts.

Key Terms

phase 2b/3 medical

"pivotal Phase 2B/3 “MIRACLE” study of Annamycin in combination with cytarabine"

A phase 2b/3 trial is a combined late-stage clinical study that first refines the best dose and measures how well a treatment works (phase 2b) then expands to a larger, definitive test of safety and effectiveness needed for regulatory approval (phase 3). For investors, results from a phase 2b/3 act like a dress rehearsal that turns into opening night: positive, well-controlled outcomes substantially raise the chance of approval and future sales, while failures can sharply reduce a drug’s value.

randomized medical

"global multi-center, randomized, double-blind, placebo-controlled, adaptive designed clinical trial"

Randomized means participants or units in a study are assigned to different groups by chance rather than by choice, like flipping a coin to decide who gets a new treatment and who gets a comparison. For investors, randomized designs matter because they reduce bias and make results more trustworthy, so outcomes from randomized studies carry more weight when assessing regulatory approval, commercial prospects, and the risk that trial results will change a company’s valuation.

double-blind medical

"global multi-center, randomized, double-blind, placebo-controlled, adaptive designed clinical trial"

A double-blind process means that neither the people conducting an activity nor the people involved know certain key details, such as who is receiving a treatment or a placebo. This approach helps prevent bias from influencing the results, making the outcome more trustworthy. For investors, it ensures that decisions or judgments are based on unbiased information rather than preconceived opinions or expectations.

placebo-controlled medical

"global multi-center, randomized, double-blind, placebo-controlled, adaptive designed clinical trial"

"Placebo-controlled" describes a testing method where one group receives the actual treatment or intervention, while another group receives a harmless, inactive version called a placebo. This approach helps determine whether the real treatment has genuine effects beyond psychological expectations. For investors, understanding this ensures confidence that reported benefits are real and not influenced by bias or false perceptions.

complete remission medical

"preliminary primary efficacy data (Complete Remission or CR) and safety/tolerability"

Complete remission means that medical tests and exams show no detectable signs or symptoms of a disease after treatment, though it does not guarantee the disease is permanently gone. Investors care because complete remission rates are a clear, measurable outcome used by regulators and doctors to judge a therapy’s effectiveness; like a fire appearing fully extinguished, it can boost a drug’s perceived value and commercial prospects while still requiring ongoing monitoring.

fast track status regulatory

"Annamycin ... currently has Fast Track Status and Orphan Drug Designation from the FDA"

A regulatory agency’s “fast track” designation gives a development program priority treatment to speed review and encourage more frequent communication between the company and regulators, like an express lane at airport security that aims to get promising treatments evaluated sooner. For investors, this matters because faster review can shorten the time to potential approval, reduce certain development risks and create earlier value inflection points—though it does not guarantee a successful outcome.

orphan drug designation regulatory

"Fast Track Status and Orphan Drug Designation from the FDA for the treatment of"

Orphan drug designation is a special status given to medicines developed to treat rare diseases affecting only a small number of people. This status often provides benefits like faster approval processes and financial incentives, making it more attractive for companies to develop these drugs. For investors, it signals potential for exclusive market rights and reduced competition, which can impact the drug’s profitability.

AI-generated analysis. Not financial advice.

Continues to drive enrollment with increase to 78% now consented

Blinded response activity tracking within expected range

Consented subjects now across seven countries supporting the expansion of the MIRACLE trial

HOUSTON, Dec. 09, 2025 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc., (Nasdaq: MBRX) (“Moleculin” or the “Company”), today provided an update on enrollment from its November report with an increase to 78% of the target number of subjects for the first planned interim unblinding of data having consented to its pivotal Phase 2B/3 “MIRACLE” study of Annamycin in combination with cytarabine for the treatment of adult patients with acute myeloid leukemia (AML) who are refractory to or relapsed (R/R) after induction therapy (R/R AML). This is up from 60% in its report in November. The targeted number for the first unblinding of data is 45 subjects. Additional subjects beyond the 78% mark continue to be identified by site investigators. This update is as of December 3, 2025, as identification and recruitment are ongoing. The Company expects to complete treatment of the first 45 subjects in the first quarter of 2026.

Walter Klemp, Chairman and CEO of Moleculin, commented, “We continue to see blinded clinical activity tracking within our expected range, based on historical responses of the trial arm equivalents. With this update, we are quickly approaching the 45^th subject, which we expect to be in the first quarter of 2026, to be treated and support the first unblinding in Part A of the MIRACLE trial shortly thereafter. This increase in subjects consented in one month is highly encouraging and demonstrates the enthusiasm of investigators around Europe and the US. Although we saw early enrollment at some sites in Europe being impacted by bed shortages, we are now seeing this situation improve in certain EU countries. Moving toward our first unblinding milestone, we are excited about Annamycin’s potential to fill a major gap in AML treatment. We believe we’re well on our way to determining if Annamycin has the potential to offer a much-needed, safer, and more effective option for patients facing this devastating disease.”

Mr. Klemp continued, “While the 45 subject data is not designed to hold statistical significance, we expect to see that at least one of the two arms of Annamycin (at two different dosages) plus cytarabine outperforms cytarabine plus placebo, the control arm. That could be a strong indicator that the MIRACLE trial is on track to support approval of Annamycin. We will continue to recruit the remaining 45 subjects for the full 90 subjects of Part A while we are unblinding the first 45 subjects. The second unblinding should provide enough data to decide on which dose of Annamycin to proceed with into Part B of the MIRACLE trial.”

MIRACLE Trial Progress and Next Steps

The MIRACLE study (derived from Moleculin R/R AML AnnAraC Clinical Evaluation) is a Phase 2B/3, global multi-center, randomized, double-blind, placebo-controlled, adaptive designed clinical trial whereby data from the 2B (Part A) portion will be combined with the Phase 3 (Part B) portion for purposes of measuring its primary efficacy endpoint. The protocol for the MIRACLE trial allows for the unblinding of preliminary primary efficacy data (Complete Remission or CR) and safety/tolerability of the three arms at 45 subjects, in addition to the conclusion of Part A (90 subjects). The first early unblinding will yield 30 subjects treated with Annamycin (190mg/m² and 230 mg/m²) in combination with HiDAC and 15 subjects treated with just HiDAC plus placebo. Before each unblinding, trial data will be subject to audit, database lock and review.

The currently consented subjects are from sites across seven countries, providing a diverse base of patient population. Subjects are identified, consented, screened, enrolled, treated and then evaluated in that order with subjects possibly withdrawing from the trial at any point of this process. The Company expects to reach the recruitment and treatment of the first 45 subjects in the first quarter of 2026 and to complete Part A of the MIRACLE trial with up to 90 patients within the first half of 2026.

For more information about the MIRACLE trial, visit clinicaltrials.gov and reference identifier NCT06788756. Additionally, the clinical trial in the EU is on euclinicaltrials.eu and the reference identifier there is 2024-518359-47-00.

Annamycin, also known by its non-proprietary name of naxtarubicin, currently has Fast Track Status and Orphan Drug Designation from the FDA for the treatment of relapsed or refractory acute myeloid leukemia, in addition to Orphan Drug Designation for the treatment of soft tissue sarcoma. Annamycin also benefits from composition of matter patent protection through 2040 with the potential to extend that protection as far as 2045. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the EMA.

About Moleculin Biotech, Inc.

Moleculin Biotech, Inc. is a Phase 3 clinical stage pharmaceutical company advancing a pipeline of therapeutic candidates addressing hard-to-treat tumors and viruses. The Company’s lead program, Annamycin, is a next-generation highly efficacious and well tolerated anthracycline designed to avoid multidrug resistance mechanisms and to lack the cardiotoxicity common with currently prescribed anthracyclines. Annamycin is currently in development for the treatment of relapsed or refractory acute myeloid leukemia (AML) and soft tissue sarcoma (STS) lung metastases.

The Company has begun the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design Phase 3 trial evaluating Annamycin in combination with cytarabine, together referred to as AnnAraC (the combination of Annamycin and cytarabine, also referred to as “Ara-C”) and, for the treatment of relapsed or refractory acute myeloid leukemia. Following a successful Phase 1B/2 study (MB-106), with input from the FDA, the Company believes it has substantially de-risked the development pathway towards a potential approval for Annamycin for the treatment of AML. This study remains subject to appropriate future filings with potential additional feedback from the FDA and their foreign equivalents.

Additionally, the Company is developing WP1066, an Immune/Transcription Modulator capable of inhibiting p-STAT3 and other oncogenic transcription factors while also stimulating a natural immune response, targeting brain tumors, pancreatic and other cancers. Moleculin also has in its pipeline a portfolio of antimetabolites, including WP1122 for the potential treatment of pathogenic viruses, as well as certain cancer indications.

For more information about the Company, please visit www.moleculin.com and connect on X, LinkedIn and Facebook.

Forward-Looking Statements

Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. Forward-looking statements in this press release include, without limitation, statements regarding the continued recruitment, treatment, and receipt of the unblinded data for the first 45 subjects of the MIRACLE clinical trial and the timing to complete Part A of the MIRACLE trial with up to 90 patients, each as described above. Moleculin will require significant additional financing, for which the Company has no commitments, in order to conduct its clinical trials as described in this press release, and the milestones described in this press release assume the Company’s ability to secure such financing on a timely basis. Although Moleculin believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Moleculin has attempted to identify forward-looking statements by terminology including ‘believes,’ ‘estimates,’ ‘anticipates,’ ‘expects,’ ‘plans,’ ‘projects,’ ‘intends,’ ‘potential,’ ‘may,’ ‘could,’ ‘might,’ ‘will,’ ‘should,’ ‘approximately’ or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under Item 1A. “Risk Factors” in our most recently filed Form 10-K filed with the Securities and Exchange Commission (SEC) and updated from time to time in our Form 10-Q filings and in our other public filings with the SEC. Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events.

Investor Contact:
JTC Team, LLC
Jenene Thomas
(908) 824-0775
MBRX@jtcir.com

FAQ

What enrollment milestone did Moleculin (MBRX) announce on December 9, 2025?

Moleculin reported 78% consented toward the first 45-subject unblinding for the MIRACLE trial.

When does Moleculin expect to complete treatment of the first 45 MIRACLE subjects (MBRX)?

The company expects to complete treatment of the first 45 subjects in Q1 2026.

What is the planned timeline for Part A completion of the MIRACLE trial (MBRX)?

Part A (up to 90 patients) is expected to be completed in the first half of 2026.

Does Annamycin (MBRX) have regulatory designations that affect development speed?

Yes; Annamycin has FDA Fast Track status and Orphan Drug designations from FDA and EMA.

Will the first 45-subject unblinding be statistically definitive for Moleculin (MBRX)?

No; the company says the 45-subject readout is not designed to hold statistical significance.

What patent protection term does Annamycin (MBRX) currently have?

Annamycin benefits from composition-of-matter patent protection through 2040, with potential extension to 2045.