Nature of Business and Liquidity	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Liquidity	Nature of Business and Liquidity The terms “MBI” or “the Company”, “we”, “our” and “us” are used herein to refer to Moleculin Biotech, Inc. MBI is a clinical-stage pharmaceutical company organized as a Delaware corporation in July 2015 to focus on the development of oncology drug candidates, all of which are based on license agreements with The University of Texas System on behalf of the M.D. Anderson Cancer Center, which we refer to as MD Anderson. MBI has three drug technologies. Our clinical stage drugs are Annamycin, an anthracycline designed to avoid multidrug resistance mechanisms with little to no cardiotoxicity being studied for the treatment of relapsed or refractory acute myeloid leukemia, more commonly referred to as AML, and WP1066, an immuno-stimulating STAT3 inhibitor targeting brain tumors, pancreatic cancer and AML. We are also engaged in preclinical development of additional drug candidates, including additional STAT3 inhibitors and compounds targeting the metabolism of tumors. Our lead drug candidate is liposomal Annamycin, which we refer to as Annamycin, an anthracycline being studied for the treatment of relapsed or refractory acute myeloid leukemia, or AML. Annamycin had been in clinical trials pursuant to an investigative new drug application or IND that had been filed with the U.S. Food and Drug Administration, or FDA. Due to a lack of development activity by a prior drug developer, this IND was terminated. To permit the renewed investigation of Annamycin, we submitted a new IND for a Phase I/II trial for the treatment of relapsed or refractory AML in August 2017, which was subsequently allowed by the FDA in September 2017. We have two other drug development projects, one involving a collection of small molecules, which we refer to as the WP1066 Portfolio, a collection of STAT3 inhibitors, some of which also have immuno-stimulating capability, targeting brain tumors, pancreatic cancer and AML, and the WP1122 Portfolio, a suite of molecules targeting the metabolic processes involved in cancer in general and glioblastoma (the most common form of brain tumor) and pancreatic cancer in particular. A physician-sponsored IND for a Phase I trial of WP1066 in patients with recurrent malignant glioma and brain metastasis from melanoma was allowed by the FDA in December 2017. We also continue to sponsor ongoing research at MD Anderson in order to improve and expand our drug development pipeline. We have been granted royalty-bearing, worldwide, exclusive licenses for the patent and technology rights related to all of our drug technologies, as these patent rights are owned by MD Anderson. The Annamycin drug substance is no longer covered by any existing patent protection, however, we intend to submit patent applications for formulation, synthetic process and reconstitution related to our Annamycin drug product candidate, although there is no assurance that we will be successful in obtaining such patent protection. Independently from potential patent protection, we have received Orphan Drug designation from the FDA for Annamycin for the treatment of AML, which would entitle us to market exclusivity of 7 years from the date of approval of a New Drug Application (NDA) in the United States. We may then benefit from Orphan Drug exclusivity, during which period FDA generally could not approve another Annamycin product for the same use. We also intend to apply for similar status in the European Union (EU) where market exclusivity extends to 10 years from the date of Marketing Authorization Application (MAA). Separately, the FDA may also grant market exclusivity of 5 years for newly approved new chemical entities (of which Annamycin would be one), but there can be no assurance that such exclusivity will be granted. With regard to additional potential clinical activity, we submitted in October 2017 a request for Clinical Trial Authorization ("CTA") in Poland which, if allowed, will enable a Phase I/II clinical trial to study Annamycin for the treatment of relapsed or refractory AML in Poland. This will be in addition to the previously announced allowance of our IND in the United States. In December 2017, the Ethics Committee in Poland approved our Phase I/II clinical trial of Annamycin. In March we received requests for and provided additional information to the Polish National Office. We expect a response from the Polish National Office in the first half of 2018 and at the earliest mid-April 2018. The start of clinical trials in Poland remains subject to confirmation and approval of the CTA by the Polish National Office. We can provide no assurance that we will receive such confirmation on a timely basis, if at all. In addition, we continue to recruit and contract clinics both in the United States and Poland. In the US, we have one site - University Hospitals Cleveland Medical Center (“UHCMC”) - recruiting patients and active with drug ready to provide treatments. A patient was enrolled in March 2018 with anticipated treatment to occur in the near term. We can provide no assurance treatment will occur on a timely basis, if at all. Furthermore, in September 2017 we engaged a contract research organization ("CRO") to prepare for a proof-of-concept clinical trial in Poland to study our drug candidate WP1220, a part of the WP1066 portfolio, for the treatment of cutaneous T-cell lymphoma ("CTCL"). In accordance with FASB ASC Topic 280, Segment Reporting, we view our operations and manage our business as principally one segment. As a result, the financial information disclosed herein represents all of the material financial information related to our principal operating segment. The Company filed a registration statement on Form S-1 (which was declared effective on May 2, 2016) with respect to the Company’s initial public offering of shares of its common stock (“IPO”) to fund the development of its technologies. Prior to the declaration of effectiveness of the registration statement on Form S-1, we acquired Moleculin, LLC which was merged with and into MBI. Moleculin, LLC was the holder of a license agreement with MD Anderson covering technology referred to as the WP1066 Portfolio, which is focused on the modulation of key oncogenic transcription factors.

Nature of Business and Liquidity

The terms “MBI” or “the Company”, “we”, “our” and “us” are used herein to refer to Moleculin Biotech, Inc. MBI is a clinical-stage pharmaceutical company organized as a Delaware corporation in July 2015 to focus on the development of oncology drug candidates, all of which are based on license agreements with The University of Texas System on behalf of the M.D. Anderson Cancer Center, which we refer to as MD Anderson. MBI has three drug technologies. Our clinical stage drugs are Annamycin, an anthracycline designed to avoid multidrug resistance mechanisms with little to no cardiotoxicity being studied for the treatment of relapsed or refractory acute myeloid leukemia, more commonly referred to as AML, and WP1066, an immuno-stimulating STAT3 inhibitor targeting brain tumors, pancreatic cancer and AML. We are also engaged in preclinical development of additional drug candidates, including additional STAT3 inhibitors and compounds targeting the metabolism of tumors.

Our lead drug candidate is liposomal Annamycin, which we refer to as Annamycin, an anthracycline being studied for the treatment of relapsed or refractory acute myeloid leukemia, or AML. Annamycin had been in clinical trials pursuant to an investigative new drug application or IND that had been filed with the U.S. Food and Drug Administration, or FDA. Due to a lack of development activity by a prior drug developer, this IND was terminated. To permit the renewed investigation of Annamycin, we submitted a new IND for a Phase I/II trial for the treatment of relapsed or refractory AML in August 2017, which was subsequently allowed by the FDA in September 2017.

We have two other drug development projects, one involving a collection of small molecules, which we refer to as the WP1066 Portfolio, a collection of STAT3 inhibitors, some of which also have immuno-stimulating capability, targeting brain tumors, pancreatic cancer and AML, and the WP1122 Portfolio, a suite of molecules targeting the metabolic processes involved in cancer in general and glioblastoma (the most common form of brain tumor) and pancreatic cancer in particular. A physician-sponsored IND for a Phase I trial of WP1066 in patients with recurrent malignant glioma and brain metastasis from melanoma was allowed by the FDA in December 2017. We also continue to sponsor ongoing research at MD Anderson in order to improve and expand our drug development pipeline.

We have been granted royalty-bearing, worldwide, exclusive licenses for the patent and technology rights related to all of our drug technologies, as these patent rights are owned by MD Anderson. The Annamycin drug substance is no longer covered by any existing patent protection, however, we intend to submit patent applications for formulation, synthetic process and reconstitution related to our Annamycin drug product candidate, although there is no assurance that we will be successful in obtaining such patent protection. Independently from potential patent protection, we have received Orphan Drug designation from the FDA for Annamycin for the treatment of AML, which would entitle us to market exclusivity of 7 years from the date of approval of a New Drug Application (NDA) in the United States. We may then benefit from Orphan Drug exclusivity, during which period FDA generally could not approve another Annamycin product for the same use. We also intend to apply for similar status in the European Union (EU) where market exclusivity extends to 10 years from the date of Marketing Authorization Application (MAA). Separately, the FDA may also grant market exclusivity of 5 years for newly approved new chemical entities (of which Annamycin would be one), but there can be no assurance that such exclusivity will be granted.

With regard to additional potential clinical activity, we submitted in October 2017 a request for Clinical Trial Authorization ("CTA") in Poland which, if allowed, will enable a Phase I/II clinical trial to study Annamycin for the treatment of relapsed or refractory AML in Poland. This will be in addition to the previously announced allowance of our IND in the United States. In December 2017, the Ethics Committee in Poland approved our Phase I/II clinical trial of Annamycin. In March we received requests for and provided additional information to the Polish National Office. We expect a response from the Polish National Office in the first half of 2018 and at the earliest mid-April 2018. The start of clinical trials in Poland remains subject to confirmation and approval of the CTA by the Polish National Office. We can provide no assurance that we will receive such confirmation on a timely basis, if at all.

In addition, we continue to recruit and contract clinics both in the United States and Poland. In the US, we have one site - University Hospitals Cleveland Medical Center (“UHCMC”) - recruiting patients and active with drug ready to provide treatments. A patient was enrolled in March 2018 with anticipated treatment to occur in the near term. We can provide no assurance treatment will occur on a timely basis, if at all.

Furthermore, in September 2017 we engaged a contract research organization ("CRO") to prepare for a proof-of-concept clinical trial in Poland to study our drug candidate WP1220, a part of the WP1066 portfolio, for the treatment of cutaneous T-cell lymphoma ("CTCL").

In accordance with FASB ASC Topic 280, Segment Reporting, we view our operations and manage our business as principally one segment. As a result, the financial information disclosed herein represents all of the material financial information related to our principal operating segment.

The Company filed a registration statement on Form S-1 (which was declared effective on May 2, 2016) with respect to the Company’s initial public offering of shares of its common stock (“IPO”) to fund the development of its technologies. Prior to the declaration of effectiveness of the registration statement on Form S-1, we acquired Moleculin, LLC which was merged with and into MBI. Moleculin, LLC was the holder of a license agreement with MD Anderson covering technology referred to as the WP1066 Portfolio, which is focused on the modulation of key oncogenic transcription factors.