Nature of Organization and Operations	3 Months Ended
Mar. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Organization and Operations	1. Nature of Organization and Operations Aerpio Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company focused on developing compounds that activate Tie2 to treat ocular diseases and diabetic complications. The Company was incorporated as Zeta Acquisition Corp. II (“Zeta”) in the State of Delaware on November 16, 2007. Zeta was a “shell company” (as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended). The Company’s pipeline includes the following programs: Glaucoma: Based on the preclinical proof of concept and the results of the Phase 1b trial showing a reduction in intraocular pressure (“IOP”) in patients with ocular hypertension (“OHT”) and open angle glaucoma (“OAG”), the Company is preparing to further advance the glaucoma program into a Phase 2 clinical trial and expects to initiate the trial in the third quarter of 2020 with results expected in the first quarter of 2021, subject to potential delays in subject enrollment and study completion due to the ongoing global outbreak of the novel coronavirus disease (“COVID-19”). Diabetic Kidney Disease: In two consecutive trials, TIME-2 and TIME-2b, subcutaneous AKB-9778 showed reduction in Urine Albumin-Creatinine Ratio (“UACR”), a measure of progression of diabetic kidney disease. The Company believes that systemic treatment with AKB-9778 could have the potential to change the treatment paradigm for diabetics in the future and potentially address a major societal problem by lowering the cost of care associated generally with diabetes. ARP-1536: ARP-1536, the humanized monoclonal antibody directed at the same target as subcutaneous AKB-9778, is in preclinical development. The Company is evaluating development options for ARP-1536, including subcutaneous injection for the treatment of diabetic vascular complications, e.g., diabetic nephropathy and intravitreal injection as an adjunctive therapy for diabetic macular edema. The Company is also developing a bispecific antibody that binds both VEGF and VE-PTP which is designed to inhibit VEGF activation and activate Tie2. The Company believes this bispecific antibody has the potential to be an improved treatment for wet aged-related macular degeneration (“AMD”) and diabetic macular edema via intravitreal injection. In June 2018, the Company licensed AKB-4924, a selective stabilizer of hypoxia-inducible factor-1 alpha (“HIF-1 alpha”) to a wholly-owned subsidiary of Gossamer Bio, Inc., GB004, Inc. (collectively “Gossamer”), which is being developed for the treatment of inflammatory bowel disease (“IBD”). HIF-1 alpha is involved in mucosal wound healing and the reduction of inflammation in the gastrointestinal tract. Gossamer has completed the Phase 1 multiple ascending dose (“MAD”) clinical study and is currently running a Phase 1b clinical study in ulcerative colitis patients. Gossamer is expected to have results of the Phase 1b study in ulcerative colitis patients in the first half of 2020. Gossamer is responsible for all remaining development and commercial activities for GB004. The Company’s operations to date have been limited to organizing and staffing the Company, business planning, raising capital, acquiring and developing its technology, identifying potential product candidates and undertaking preclinical and clinical studies. The Company’s revenue has been primarily limited to license revenue from Gossamer. Future revenue is dependent on the terms of the license agreement with Gossamer as further described in Note 11. The Company’s product candidates are subject to long development cycles and there is no assurance the Company will be able to successfully develop, obtain regulatory approval for, or market its product candidates. The Company is subject to a number of risks similar to other life science companies in the current stage of its life cycle including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of any of the Company’s products that are approved, and protection of proprietary technology. If the Company does not successfully commercialize any of its products or mitigate any of these other risks, it will be unable to generate revenue or achieve profitability. The Company incurred losses from operations and had a negative cash flows from operating activities for the three months ended March 31, 2020 and 2019 (and since inception). The Company’s current operating plan indicates that it will continue to incur losses from operations and generate negative cash flows from operating activities given ongoing expenditures related to the completion of its ongoing clinical trials and the Company’s lack of product revenue generating activities. However, the Company believes it has the ability to control its current operating plan and that existing cash and cash equivalents of approximately $34.6 million at March 31, 2020 will be sufficient to allow the Company to fund its current operating plan through at least the second quarter of 2021. There can be no assurance, however, that the current operating plan will be achieved in the time frame anticipated by the Company, or that its cash resources will fund the Company’s operating plan for the period anticipated by the Company or that additional funding will be available on terms acceptable to the Company, or at all. The Company will need to raise additional funds in order to further advance its clinical research programs, commence additional clinical trials, and operate its business and meet its obligations as they come due. The Company is pursuing financing alternatives, which include permanent equity financing, business development arrangements, and licensing arrangements. However, financing may not be available to the Company in the necessary time frame, in amounts that the Company requires, on terms that are acceptable to the Company, or at all. If the Company raises additional funds through collaboration, licensing or other similar arrangements, it may be necessary to relinquish valuable rights to its potential products or proprietary technologies or grant licenses on terms that are not favorable to the Company. If the Company is unable to raise the necessary funds when needed or reduce spending on currently planned activities, it may not be able to continue the development of its product candidates or the Company could be required to delay, scale back, or eliminate some or all of its development programs and other operations and will materially harm its business, financial position and results of operations. COVID-19 has resulted in significant governmental measures being implemented to control the spread of the virus and while the Company cannot predict their scope and severity, these developments and measures could materially and adversely affect its business, including its planned Phase 2 clinical trial for the glaucoma program, results of operations and financial condition. In addition, in response to the spread of COVID-19, the Company has closed its executive offices with its employees continuing their work outside of the offices. The Company is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business and is taking steps to minimize the impact on its business. However, the extent to which COVID-19 impacts the Company’s business, results of operations or financial condition will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the duration of the outbreak, new information that may emerge concerning the severity of COVID-19 or the effectiveness of actions taken to contain the pandemic or treat its impact, among others. Furthermore, if the Company or any of the third parties with whom it engages, however, were to experience shutdowns or other business disruptions, the Company’s ability to conduct its business in the manner and on the timelines presently planned could be materially or negatively affected, which could have a material adverse impact on the Company’s business, results of operation and financial condition.

Nature of Organization and Operations

3 Months Ended

Mar. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Nature of Organization and Operations

Aerpio Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company focused on developing compounds that activate Tie2 to treat ocular diseases and diabetic complications. The Company was incorporated as Zeta Acquisition Corp. II (“Zeta”) in the State of Delaware on November 16, 2007. Zeta was a “shell company” (as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended).

The Company’s pipeline includes the following programs:

Glaucoma: Based on the preclinical proof of concept and the results of the Phase 1b trial showing a reduction in intraocular pressure (“IOP”) in patients with ocular hypertension (“OHT”) and open angle glaucoma (“OAG”), the Company is preparing to further advance the glaucoma program into a Phase 2 clinical trial and expects to initiate the trial in the third quarter of 2020 with results expected in the first quarter of 2021, subject to potential delays in subject enrollment and study completion due to the ongoing global outbreak of the novel coronavirus disease (“COVID-19”).

Diabetic Kidney Disease: In two consecutive trials, TIME-2 and TIME-2b, subcutaneous AKB-9778 showed reduction in Urine Albumin-Creatinine Ratio (“UACR”), a measure of progression of diabetic kidney disease. The Company believes that systemic treatment with AKB-9778 could have the potential to change the treatment paradigm for diabetics in the future and potentially address a major societal problem by lowering the cost of care associated generally with diabetes.

ARP-1536: ARP-1536, the humanized monoclonal antibody directed at the same target as subcutaneous AKB-9778, is in preclinical development. The Company is evaluating development options for ARP-1536, including subcutaneous injection for the treatment of diabetic vascular complications, e.g., diabetic nephropathy and intravitreal injection as an adjunctive therapy for diabetic macular edema.

The Company is also developing a bispecific antibody that binds both VEGF and VE-PTP which is designed to inhibit VEGF activation and activate Tie2. The Company believes this bispecific antibody has the potential to be an improved treatment for wet aged-related macular degeneration (“AMD”) and diabetic macular edema via intravitreal injection.

In June 2018, the Company licensed AKB-4924, a selective stabilizer of hypoxia-inducible factor-1 alpha (“HIF-1 alpha”) to a wholly-owned subsidiary of Gossamer Bio, Inc., GB004, Inc. (collectively “Gossamer”), which is being developed for the treatment of inflammatory bowel disease (“IBD”). HIF-1 alpha is involved in mucosal wound healing and the reduction of inflammation in the gastrointestinal tract. Gossamer has completed the Phase 1 multiple ascending dose (“MAD”) clinical study and is currently running a Phase 1b clinical study in ulcerative colitis patients. Gossamer is expected to have results of the Phase 1b study in ulcerative colitis patients in the first half of 2020. Gossamer is responsible for all remaining development and commercial activities for GB004.

The Company’s operations to date have been limited to organizing and staffing the Company, business planning, raising capital, acquiring and developing its technology, identifying potential product candidates and undertaking preclinical and clinical studies. The Company’s revenue has been primarily limited to license revenue from Gossamer. Future revenue is dependent on the terms of the license agreement with Gossamer as further described in Note 11. The Company’s product candidates are subject to long development cycles and there is no assurance the Company will be able to successfully develop, obtain regulatory approval for, or market its product candidates.

The Company is subject to a number of risks similar to other life science companies in the current stage of its life cycle including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of any of the Company’s products that are approved, and protection of proprietary technology. If the Company does not successfully commercialize any of its products or mitigate any of these other risks, it will be unable to generate revenue or achieve profitability.

The Company incurred losses from operations and had a negative cash flows from operating activities for the three months ended March 31, 2020 and 2019 (and since inception). The Company’s current operating plan indicates that it will continue to incur losses from operations and generate negative cash flows from operating activities given ongoing expenditures related to the completion of its ongoing clinical trials and the Company’s lack of product revenue generating activities. However, the Company believes it has the ability to control its current operating plan and that existing cash and cash equivalents of approximately $34.6 million at March 31, 2020 will be sufficient to allow the Company to fund its current operating plan through at least the second quarter of 2021.

There can be no assurance, however, that the current operating plan will be achieved in the time frame anticipated by the Company, or that its cash resources will fund the Company’s operating plan for the period anticipated by the Company or that additional funding will be available on terms acceptable to the Company, or at all. The Company will need to raise additional funds in order to further advance its clinical research programs, commence additional clinical trials, and operate its business and meet its obligations as they come due. The Company is pursuing financing alternatives, which include permanent equity financing, business development arrangements, and licensing arrangements. However, financing may not be available to the Company in the necessary time frame, in amounts that the Company requires, on terms that are acceptable to the Company, or at all. If the Company raises additional funds through collaboration, licensing or other similar arrangements, it may be necessary to relinquish valuable rights to its potential products or proprietary technologies or grant licenses on terms that are not favorable to the Company. If the Company is unable to raise the necessary funds when needed or reduce spending on currently planned activities, it may not be able to continue the development of its product candidates or the Company could be required to delay, scale back, or eliminate some or all of its development programs and other operations and will materially harm its business, financial position and results of operations.

COVID-19 has resulted in significant governmental measures being implemented to control the spread of the virus and while the Company cannot predict their scope and severity, these developments and measures could materially and adversely affect its business, including its planned Phase 2 clinical trial for the glaucoma program, results of operations and financial condition. In addition, in response to the spread of COVID-19, the Company has closed its executive offices with its employees continuing their work outside of the offices. The Company is closely monitoring the impact of the COVID-19 pandemic on all aspects of its business and is taking steps to minimize the impact on its business. However, the extent to which COVID-19 impacts the Company’s business, results of operations or financial condition will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the duration of the outbreak, new information that may emerge concerning the severity of COVID-19 or the effectiveness of actions taken to contain the pandemic or treat its impact, among others. Furthermore, if the Company or any of the third parties with whom it engages, however, were to experience shutdowns or other business disruptions, the Company’s ability to conduct its business in the manner and on the timelines presently planned could be materially or negatively affected, which could have a material adverse impact on the Company’s business, results of operation and financial condition.