Subsequent Events	12 Months Ended
Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	NOTE 12 – SUBSEQUENT EVENTS COVID-19 efforts Research Service Agreement between Golden Mountain Partners LLC (GMP) and Mateon Therapeutics Inc./Oncotelic Inc. (“Mateon Entities”). When COVID-19 emerged in China, Mateon and GMP contemplated a collaboration to develop drug candidates for COVID-19. Oncotelic and GMP entered into a research and services agreement (the “Agreement”) on February 3, 2020 memorializing their collaborative efforts to develop and test COVID-19 antisense therapeutics. On March 18, 2020, Mateon reported the anti-viral activity of OT-101 – its lead drug candidate currently in phase 3 testing in pancreatic cancer and glioblastoma. In an in vitro antiviral testing performed by an independent laboratory, OT-101 showed that it was highly active against COVID-19. On March 23, 2020, Mateon, Oncotelic, Inc., and GMP entered into a supplement to the Agreement (the “Supplement”) to confirm the inclusion of OT-101 within the scope of the Agreement, pending positive confirmatory testing against COVID-19. In consideration for the financial support provided by GMP for the research, pursuant to the terms of the Agreement (as amended by the Supplement) GMP is entitled to obtain certain exclusive rights to the use of the Product in the COVID Field on a global basis, and an economic interest in the use of the Product in the COVID Field including 50/50 profit sharing. As described in the Supplement, the Mateon Entities intend to license or assign intellectual property rights, including the 2020 Patent Application and any other intellectual property rights owned or controlled by the Mateon Entities relating to the Product, OXi4503 and CA4P, to a joint venture company to be established jointly between Oncotelic and GMP (or its designee), as well as providing management services and other expertise to the joint venture company; GMP intends that it (or its designee, as the case may be) shall provide funding to the joint venture company to support its development and commercial activities in the joint venture company’s territories; in each case, on terms to be agreed by the parties; and GMP shall be entitled to use its governmental relations and local expertise in Greater China to assist with coordinating the research, development and commercialization of (i) the Products in the COVID Field, (ii) the Products in the OT101 Oncology Field, (iii) OXi4503; and (iv) CA4P, in each case in Greater China. The joint venture company is intended to be owned 50% by Oncotelic and 50% by GMP (or its designee), and its principal activities shall be to research, develop, bring to market and commercialize: (i) the Products in the COVID Field on a global basis, (ii) the Products in the OT101 Oncology Field in the Licensed Territory, (iii) OXi4503 in the Licensed Territory; and (iv) CA4P in the Licensed Territory. Upon completion of due diligence by one another and subject to GMP’s satisfactory due diligence review, the parties intend to enter into written definitive agreements for the Joint Venture Transaction within the Exclusivity Period of 90 days. On April 6, 2020, the Company delivered the requisite testing results to GMP confirming the applicability and potential use of OT-101 for the treatment of COVID-19. OT-101 exhibited potent activity against both COVID-19 and SARS with a robust safety index of >500. Also, The Company has submitted a Pre-Investigational New Drug (Pre-IND) application package to the Food and Drug Administration. GMP paid the Company fees of $1.2 million for the services rendered under the agreement and supplemental agreements as well as reimbursed the Company for actual costs incurred of $0.1 million. In April 2020, Mateon also filed the IND with the FDA to permit Mateon to commence clinical trials to evaluate if OT-101 is effective to treat COVID-19. The proposed randomized, double-blind, placebo-controlled Phase 2 study is intended to evaluate the safety and efficacy of OT-101 in adult patients hospitalized with positive SARS-CoV-2 and pneumonia in the US. Provisional Patent Filing On March 18, 2020 and March 20, 2020, Oncotelic, Inc. (“Oncotelic”), a wholly-owned subsidiary of Mateon Therapeutics, Inc. (“Mateon” or the “Company”), filed three provisional patent applications on the method of use and composition of matter for the treatment of COVID-19. The filings represent the culmination of internal research programs, including efforts with our external partner, and position our antisense platforms for further development for the treatment of epidemics and pandemics. Payment Protection Program On April 21, 2020, the Company, entered into a Paycheck Protection Program Promissory Note (the “PPP Note”) with respect to a loan in the amount of $250,000 (the “PPP Loan”) from Silicon Valley Bank (the “Lender”). The PPP Loan was obtained pursuant to the Paycheck Protection Program (the “PPP”) of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) administered by the U.S. Small Business Administration (“SBA”). The PPP Loan matures on April 21, 2022 and bears interest at a rate of 1.00% per annum. The PPP Loan is payable in 17 equal monthly payments commencing November 21, 2020. The PPP Loan may be prepaid at any time prior to maturity with no prepayment penalties. All or a portion of the PPP Loan may be forgiven by the SBA and the Lender upon application by the Company within 60 days but not later than 120 days after loan approval and upon documentation of expenditures in accordance with the SBA requirements. Conversion of shares by Peak One and TFK In February and March of 2020, Peak One and TFK converted $150,000 of their debt of $400,000 under the Peak One Notes for 2,012,145 shares of Mateon. As such, the balance remaining unpaid as of the date of this report is $250,000. Similarly, TFK converted $133,430 of their debt of $200,000 for 1,950,000 shares of Mateon. As such, the balance remaining unpaid is $66,570 as of the date of this report. Cancellation of 2018 warrants and issue of new warrants During the quarter ended March 31, 2020, the Company offered to cancel 14,875,000 warrants issued to certain investors, at a price of $0.40, issued in connection with the 2018 private placement in exchange for new warrants at a price of $0.20. Of the 14,875,000 warrants outstanding, 13,750,000 were exchange for new warrants.

Subsequent Events

12 Months Ended

Dec. 31, 2019

NOTE 12 – SUBSEQUENT EVENTS

COVID-19 efforts

Research Service Agreement between Golden Mountain Partners LLC (GMP) and Mateon Therapeutics Inc./Oncotelic Inc. (“Mateon Entities”).

When COVID-19 emerged in China, Mateon and GMP contemplated a collaboration to develop drug candidates for COVID-19. Oncotelic and GMP entered into a research and services agreement (the “Agreement”) on February 3, 2020 memorializing their collaborative efforts to develop and test COVID-19 antisense therapeutics. On March 18, 2020, Mateon reported the anti-viral activity of OT-101 – its lead drug candidate currently in phase 3 testing in pancreatic cancer and glioblastoma. In an in vitro antiviral testing performed by an independent laboratory, OT-101 showed that it was highly active against COVID-19. On March 23, 2020, Mateon, Oncotelic, Inc., and GMP entered into a supplement to the Agreement (the “Supplement”) to confirm the inclusion of OT-101 within the scope of the Agreement, pending positive confirmatory testing against COVID-19. In consideration for the financial support provided by GMP for the research, pursuant to the terms of the Agreement (as amended by the Supplement) GMP is entitled to obtain certain exclusive rights to the use of the Product in the COVID Field on a global basis, and an economic interest in the use of the Product in the COVID Field including 50/50 profit sharing. As described in the Supplement, the Mateon Entities intend to license or assign intellectual property rights, including the 2020 Patent Application and any other intellectual property rights owned or controlled by the Mateon Entities relating to the Product, OXi4503 and CA4P, to a joint venture company to be established jointly between Oncotelic and GMP (or its designee), as well as providing management services and other expertise to the joint venture company; GMP intends that it (or its designee, as the case may be) shall provide funding to the joint venture company to support its development and commercial activities in the joint venture company’s territories; in each case, on terms to be agreed by the parties; and GMP shall be entitled to use its governmental relations and local expertise in Greater China to assist with coordinating the research, development and commercialization of (i) the Products in the COVID Field, (ii) the Products in the OT101 Oncology Field, (iii) OXi4503; and (iv) CA4P, in each case in Greater China. The joint venture company is intended to be owned 50% by Oncotelic and 50% by GMP (or its designee), and its principal activities shall be to research, develop, bring to market and commercialize: (i) the Products in the COVID Field on a global basis, (ii) the Products in the OT101 Oncology Field in the Licensed Territory, (iii) OXi4503 in the Licensed Territory; and (iv) CA4P in the Licensed Territory. Upon completion of due diligence by one another and subject to GMP’s satisfactory due diligence review, the parties intend to enter into written definitive agreements for the Joint Venture Transaction within the Exclusivity Period of 90 days. On April 6, 2020, the Company delivered the requisite testing results to GMP confirming the applicability and potential use of OT-101 for the treatment of COVID-19. OT-101 exhibited potent activity against both COVID-19 and SARS with a robust safety index of >500. Also, The Company has submitted a Pre-Investigational New Drug (Pre-IND) application package to the Food and Drug Administration. GMP paid the Company fees of $1.2 million for the services rendered under the agreement and supplemental agreements as well as reimbursed the Company for actual costs incurred of $0.1 million.

In April 2020, Mateon also filed the IND with the FDA to permit Mateon to commence clinical trials to evaluate if OT-101 is effective to treat COVID-19. The proposed randomized, double-blind, placebo-controlled Phase 2 study is intended to evaluate the safety and efficacy of OT-101 in adult patients hospitalized with positive SARS-CoV-2 and pneumonia in the US.

Provisional Patent Filing

On March 18, 2020 and March 20, 2020, Oncotelic, Inc. (“Oncotelic”), a wholly-owned subsidiary of Mateon Therapeutics, Inc. (“Mateon” or the “Company”), filed three provisional patent applications on the method of use and composition of matter for the treatment of COVID-19. The filings represent the culmination of internal research programs, including efforts with our external partner, and position our antisense platforms for further development for the treatment of epidemics and pandemics.

Payment Protection Program

On April 21, 2020, the Company, entered into a Paycheck Protection Program Promissory Note (the “PPP Note”) with respect to a loan in the amount of $250,000 (the “PPP Loan”) from Silicon Valley Bank (the “Lender”). The PPP Loan was obtained pursuant to the Paycheck Protection Program (the “PPP”) of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) administered by the U.S. Small Business Administration (“SBA”). The PPP Loan matures on April 21, 2022 and bears interest at a rate of 1.00% per annum. The PPP Loan is payable in 17 equal monthly payments commencing November 21, 2020. The PPP Loan may be prepaid at any time prior to maturity with no prepayment penalties.

All or a portion of the PPP Loan may be forgiven by the SBA and the Lender upon application by the Company within 60 days but not later than 120 days after loan approval and upon documentation of expenditures in accordance with the SBA requirements.

Conversion of shares by Peak One and TFK

In February and March of 2020, Peak One and TFK converted $150,000 of their debt of $400,000 under the Peak One Notes for 2,012,145 shares of Mateon. As such, the balance remaining unpaid as of the date of this report is $250,000. Similarly, TFK converted $133,430 of their debt of $200,000 for 1,950,000 shares of Mateon. As such, the balance remaining unpaid is $66,570 as of the date of this report.

Cancellation of 2018 warrants and issue of new warrants

During the quarter ended March 31, 2020, the Company offered to cancel 14,875,000 warrants issued to certain investors, at a price of $0.40, issued in connection with the 2018 private placement in exchange for new warrants at a price of $0.20. Of the 14,875,000 warrants outstanding, 13,750,000 were exchange for new warrants.