Moleculin Biotech (NASDAQ:MBRX) CEO and Chairman Walter Klemp outlined the company’s near-term priorities and upcoming clinical catalysts during a corporate presentation, emphasizing progress in its Phase 3 program for Annamycin, a next-generation anthracycline being developed primarily for acute myeloid leukemia (AML).
Company focus and management background
Klemp described Moleculin as a “Phase 3 clinical stage pharmaceutical company” developing therapeutics for hard-to-treat tumors and viruses. He said the company’s management team has been involved in seven FDA approvals and two “Big Pharma exits,” and that Moleculin has conducted 14 clinical trials to date. Klemp added that the company recently brought on a former Roche executive, Adriano Treve, as a strategic advisor to support partnering and outlicensing efforts, which he said Moleculin believes are “likely within the next 12 months.”
Annamycin positioning: efficacy, safety, and IP
While Moleculin has three distinct technology platforms discovered at MD Anderson Cancer Center and supported by a mix of company resources and grant-funded investigator-initiated trials, Klemp said “nearly all” of Moleculin’s capital is being directed to Annamycin because it is nearing a Phase 3 inflection point.
Klemp framed Annamycin around the strengths and limitations of the anthracycline class. Anthracyclines, he said, are used broadly across cancer care—treating “half of all cancers” and “60% of all childhood cancers”—but their key drawback is cardiotoxicity. He cited the FDA-mandated lifetime exposure limit of 550 milligrams per square meter for traditional anthracyclines and said that at that level there is a 65% chance of permanent heart damage.
According to Klemp, Annamycin was designed to be non-cardiotoxic and has shown “no evidence of cardiotoxicity” in more than 100 patients treated, including at dose levels above the typical lifetime limit. He also said Annamycin avoids cross-resistance with existing anthracyclines and, in acute leukemia, with other standard-of-care treatments. Klemp argued these features could enable higher dosing, use after other anthracyclines stop working, and potentially anthracycline maintenance therapy.
On intellectual property and regulatory positioning, Klemp said Annamycin has composition-of-matter patent protection through 2040 with potential extension beyond that. He added the company recently announced two additional patents and highlighted Annamycin’s status as a new chemical entity with orphan drug and fast-track designation.
AML Phase 2 results and rationale for Phase 3
Klemp said Moleculin is concentrating on AML to pursue its first new drug approval, estimating that up to 60% of AML patients receive an anthracycline. He contrasted outcomes for patients who cannot tolerate side effects—who may receive venetoclax-based regimens that “take a long time to respond” and where “most people don’t respond”—and said targeted therapies approved in the second-line setting work in “about 20%” of patients. He concluded that a substantial portion of AML patients lack acceptable options.
In a prior Phase 2 trial combining Annamycin with cytarabine (Ara-C), Klemp said the company observed complete remission (CR) in 50% of second-line patients. He characterized this as “significantly better than any second-line therapy ever approved for AML” and “more than double the performance of the average targeted therapy.” He also noted the responses were observed across seven sites in two countries, with similar responses regardless of prior therapy.
Klemp provided additional Phase 2 details, including that 89% of responders had one or more gene mutations typically associated with poor prognosis, 75% of responders tested negative for measurable residual disease, and 44% proceeded to a bone marrow transplant.
MIRACLE Phase 3 trial design and near-term readouts
Klemp said the FDA worked with Moleculin on an adaptive Phase 3 trial design intended to support accelerated approval. The MIRACLE trial includes two parts:
- Part A: Three-arm dosing optimization with Ara-C plus Annamycin at 190 mg/m² or 230 mg/m² versus a control arm of Ara-C plus placebo (Ara-C monotherapy described as an established standard of care in second-line AML). The primary endpoint is complete remission roughly 35 days after a single cycle.
- Part B: A two-arm stage using the selected optimal dose after Part A safety and efficacy evaluation.
From an investor perspective, Klemp highlighted two planned unblindings in Part A: one after 45 patients and another at the end of Part A (expected between 75 and 90 patients depending on results). He said this structure could provide “visibility on our likelihood of success within the first half of this year,” calling it unusual for a Phase 3 trial.
Klemp also discussed a potential scenario in which, if Part A data are close to Phase 2 performance, Moleculin could request a Type A meeting with the FDA to amend Part B into an open-label, single-arm safety study and begin a rolling NDA as early as next year. He emphasized this would depend on the strength of the completed Part A dataset.
Operationally, Klemp said recruitment in Europe has been “steady and climbing.” He said U.S. site activation has been slower, attributing that largely to the inclusion of a control arm, but added that interest is rising and additional U.S. sites are expected to come on within the next month. He said the company expects to reach enrollment of the first 45 patients “yet this quarter” and anticipates providing an update on recruitment and interim results soon. He also said the company expects completion of Part A in 2026.
Additional Annamycin data and partnering goals
Klemp noted Moleculin recently completed its MB107 clinical trial evaluating Annamycin for soft tissue sarcoma lung metastases. He said the company observed overall survival of 13.5 months in heavily pretreated patients (average seventh line) and that the results have encouraged independent investigators to propose a grant-funded trial aimed at potential approval in sarcoma.
Looking beyond AML and sarcoma, Klemp reiterated that anthracyclines are used across many cancers and said that based on preclinical testing showing Annamycin’s superiority over existing anthracyclines in certain indications, Moleculin believes the revenue potential could be “10 times greater than just AML alone.”
In the Q&A, Klemp addressed the practical significance of Annamycin’s non-cardiotoxic profile in AML, arguing that while some clinicians may accept cardiac risk given AML’s severity, treatment is constrained by FDA lifetime limits and by patients presenting with impaired cardiac function. He also said the company is focused on complete remission after one cycle as the key success measure in upcoming readouts, and discussed expectations for the control arm based on historical cytarabine monotherapy results and clinician feedback. He added that additional analyses, including genotype and prior therapy history—such as outcomes in patients who fail venetoclax plus azacitidine—will be important to assess once data are unblinded.
About Moleculin Biotech (NASDAQ:MBRX)
Moleculin Biotech, Inc is a clinical-stage pharmaceutical company focused on the development of novel therapies for the treatment of highly resistant tumors and viral infections. The company’s research platform centers on the design and synthesis of drug candidates that target key cellular pathways in cancer cells and viral replication processes. By leveraging a proprietary chemistry approach, Moleculin aims to address diseases that have limited therapeutic options and high unmet medical need.
The company’s pipeline includes multiple product candidates at various stages of development.
