Moleculin Biotech Closes Leukemia Trial Enrollment at 89
Moleculin estimates an approximately 50/50 “fit” and “unfit” mix in Part A, compared with roughly 70/30 among the first 45 subjects.
Sentiment and the balance of points
Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.
Rhea-AI Filing Summary
Moleculin Biotech, Inc. (MBRX) closed enrollment in Part A of its pivotal Phase 2/3 MIRACLE trial of Annamycin plus cytarabine for adults with relapsed or refractory acute myeloid leukemia, with 89 subjects enrolled. The company says it remains on track for a comprehensive Part A data readout in the first quarter of 2027.
Part A is randomized and double-blind, comparing two Annamycin doses plus cytarabine with cytarabine plus placebo; outcomes for all arms are measured after one cycle. The planned analysis is expected to assess efficacy and safety across the randomized population and support selection of a dose for Part B. Moleculin said blinded data continue to show a lack of cardiotoxicity. It also disclosed that trial milestones assume timely access to significant additional financing, for which it has no commitments.
How this balance works
Rhea-AI gives every point it takes from this document a weight. Minor counts 1, Moderate 3 and Major 9, so one Major point outweighs several Minor ones. The bar adds up the weights on each side, and when neither side holds more than 65% of the total the balance reads Mixed.
It reads the document as published, with the same rules for every company, and it does not look at what the market expected or at how the stock traded, so a point can be objectively good on a day the stock falls.
Rhea-AI Sentiment measures something else, the tone of the wording.
Hollow bars mark forward-looking points. How the balance works
Positive
- Moderate point. Forward-looking: it has not happened yet and may not happen.MIRACLE enrollment closed at 89 subjects; the comprehensive readout is planned for Q1 2027.
Negative
- Moderate pointThe planned Q1 2027 readout assumes timely financing; Moleculin has no commitments for it.
Filing Explained
Part A’s one-cycle outcomes, unlike the cited multi-cycle benchmarks, and its projected patient mix shape how the readout can be interpreted.
The release adds an interpretive detail for the now-closed Part A: remission outcomes in all three arms are measured after one cycle, while the cited historical studies allowed multiple cycles.
Moleculin says the more meaningful efficacy comparison is between the Annamycin arms and the randomized control arm on that same single-cycle basis, rather than against those multi-cycle datasets.
The company estimates the final Part A population will be about 50/50 “fit” and “unfit,” versus roughly 70/30 among the first 45 subjects; it says the expected shift toward more “unfit” subjects creates a more challenging response environment.
As of
Sources and calculations
- Moleculin Biotech, Inc. Form 8-K and Exhibit 99.1 (2026-09-29)
- Moleculin Biotech second-quarter 2026 fundamentals (2026-06-30)
- Available liquidity against the last reported quarterly operating outflow, in days at that rate $7,262,000 / ($6,657,000 / 91) = 99.3 days
8-K Event Classification
Key Figures
Key Terms
pivotal Phase 2/3 medical
randomized, double-blind medical
cardiotoxicity medical
relapsed or refractory acute myeloid leukemia medical
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
How many subjects enrolled in MBRX’s MIRACLE Part A?
When is MBRX’s MIRACLE Part A data readout expected?
Why does Moleculin emphasize the concurrent control arm in MIRACLE?
AI-generated analysis. How Rhea-AI works. Not financial advice.
(State or Other Jurisdiction of Incorporation or Organization) | (Commission File No.) | (I.R.S. Employer Identification No.) |
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |
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Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) |
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Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) |
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Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-14(c)) |
Title of each class | Trading Symbol (s) | Name of each exchange on which registered |
The |
Item 7.01 | Regulation FD Disclosure |
Item 9.01 | Financial Statements and Exhibits. |
(d) | Exhibits. |
Exhibit No. | Description |
99.1 | Press Release dated September 29, 2026 |
104 | Cover page Interactive Data File (formatted as Inline XBRL document) |
MOLECULIN BIOTECH, INC. | |||
Date: | September 29, 2026 | ||
By: | /s/ Jonathan P. Foster | ||
Jonathan P. Foster | |||
Exhibit 99.1
Moleculin Biotech Completes Enrollment in Part A of Phase 2/3 R/R AML MIRACLE Trial, Keeping Program on Track for Q1 2027 Data Readout
| – | Rapid completion of Part A enrollment underscores strong operational execution and investigator engagement in relapsed or refractory acute myeloid leukemia |
| – | Full Part A population expected to provide important efficacy insights across subjects who relapsed from or were refractory to first line (1L) AML treatment, including intensive 7+3 and venetoclax-based regimens |
| – | Expect final Part A dataset to approximate 50/50 between 1L 7+3 and venetoclax-based regimens
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| – | Absence of cardiotoxicity continues to differentiate Annamycin from conventional anthracyclines |
HOUSTON, September 29, 2026 /GlobeNewswire/ -- Moleculin Biotech, Inc. (Nasdaq: MBRX) (“Moleculin” or the “Company”) today announced that it has completed and closed enrollment in Part A of its pivotal Phase 2/3 MIRACLE trial evaluating Annamycin in combination with cytarabine (AnnAraC) for the treatment of adults with relapsed or refractory acute myeloid leukemia (R/R AML), with 89 subjects enrolled and an additional subject currently in screening. With Part A enrollment closed, the Company remains on track for its planned comprehensive data readout of Part A in the first quarter of 2027.
The rapid pace of enrollment underscores the significant unmet need in R/R AML as well as strong engagement from investigators and clinical sites participating in MIRACLE. The Company expects the expanded Part A dataset to provide important insight into the potential efficacy of AnnAraC across subjects who have relapsed from or are refractory to different first-line (1L) AML treatment approaches, including subjects previously treated with intensive 7+3 chemotherapy and those previously treated with venetoclax-based regimens. Such treatment approaches associated with 1L patient populations are commonly, while not universally, deemed as “fit” and “unfit”, respectively.
“Completing enrollment in Part A of MIRACLE is an important milestone for Moleculin and a strong demonstration of the operational execution behind this pivotal program,” said Walter Klemp, Chairman and Chief Executive Officer of Moleculin. “We have maintained a rapid pace of enrollment in a global, randomized AML trial and, importantly, remain on track in the first quarter of 2027 for our planned comprehensive data readout – one much deeper in data than our first interim n45 readout. Our focus turns to the maturation and analysis of this substantially larger dataset and what it may tell us about the potential of AnnAraC across distinct and clinically important R/R AML patient populations such as “fit” and “unfit” subjects.”
Mr. Klemp continued, “We are particularly excited about the composition of the additional subjects enrolled in Part A and the opportunity that the full Part A population may provide to better understand efficacy based on prior 1L treatment. We estimate that Part A will end with approximately a 50/50 split between “fit” and “unfit” subjects, compared to a roughly 70/30 split, respectively, in the first 45 subjects in Part A. While we are mindful that this shift in composition to more “unfit” subjects represents a more challenging environment for achieving treatment responses, it should provide valuable insight into Annamycin’s ability to fill critical unmet needs. Lastly, we continue to see a lack of cardiotoxicity in MIRACLE’s blinded data.”
“Completing Part A enrollment reflects the execution of our team and investigators and moves us directly toward what we believe will be one of the most important milestones in Annamycin’s development,” Mr. Klemp added. “We are grateful to the patients and families participating in MIRACLE and to the investigators and clinical teams whose commitment has enabled us to reach this milestone at such a rapid pace. With enrollment complete and the trial on track for a comprehensive Q1 2027 readout, we believe Moleculin is entering a potentially defining period for the MIRACLE program.”
About the MIRACLE Trial
MIRACLE is a pivotal Phase 2/3 study of Annamycin in combination with cytarabine for the treatment of adult subjects with AML who are refractory to, or have relapsed (R/R) after, induction therapy. Part A of the trial is a randomized, double-blind portion of the study that compares two different doses of Annamycin plus cytarabine to a control arm of cytarabine plus placebo, all with just one cycle of therapy.
Importantly, as specified by the MIRACLE protocol, remission rates for all three arms, including the control arm, reflect outcomes measured after only a single cycle of therapy. The most commonly cited historical benchmarks in this setting, including the MIRROS and CLASSIC I studies, as well as Moleculin’s own MB-106 study, permitted multiple cycles of treatment. The Company therefore expects absolute remission rates for both the control and Annamycin arms to be lower than those reported in such multi-cycle datasets and believes the most meaningful comparison is the performance of the Annamycin arms relative to the concurrent, randomized control arm evaluated on the same single-cycle basis.
The comprehensive Part A analysis is expected to evaluate efficacy and safety across the complete randomized population and support selection of the optimal Annamycin dose for advancement into Part B of MIRACLE.
For additional information on the MIRACLE trial, please visit ClinicalTrials.gov and reference Identifier NCT06788756.
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 (also known as naxtarubicin), has shown to be an 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 is conducting the MIRACLE (Moleculin R/R AML AnnAraC Clinical Evaluation) Trial (MB-108), a pivotal, adaptive design, multi-center, randomized, double-blind, placebo-controlled Phase 2/3 trial evaluating Annamycin in combination with cytarabine (also referred to as “Ara-C”), together referred to as AnnAraC, 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 toward 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, the potential efficacy and safety of Annamycin and AnnAraC in R/R AML, expected timing of the comprehensive Part A data readout in Q1 2027, the anticipated composition of the Part A population including the expected approximate 50/50 split between fit and unfit subjects, the potential for Part A data to support dose selection for Part B, and the expectation that interim efficacy trends observed in a limited patient population will be confirmed in the full study population. 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. The Company relies on the reports of its expert with regard to the absence of cardiotoxicity. The dataset referenced in this press release is subject to the review of the data from future subjects in its current and future clinical trials and long-term follow-up with subjects in its current trials. 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