THIO is a Unique Direct Telomere Targeting Agent • Potential to be used in combination with other anticancer and immune therapies • Dual, novel mechanism of action: telomere

targeting + immunogenic • FDA awarded THIO 2 Orphan Drug

Designations: HCC and SCLC! • Excellent efficacy: achieved complete and durable responses in HCC in vivo models (peer-reviewed published study)

MAIA BIOTECHNOLOGY ANNOUNCES POTENT ANTICANCER ACTIVITY OF THIO IN GLIOMAS

THIO was evaluated in various in vitro and in vivo models of gliomas. The results demonstrate the promising therapeutic role of THIO for the treatment of primary and temozolomide-resistant recurrent gliomas through specific telomerase-mediated induction of telomeric DNA damage in glioma cells

“High grade adult gliomas are among the most difficult-to-treat cancers, with less-than-desirable clinical outcomes. These encouraging results further highlight THIO’s excellent anti-cancer activity across several cancer indications,” said Vlad Vitoc, M.D., MAIA’s Chief Executive Officer. “We look forward to evaluate THIO as a treatment for brain cancer in clinical setting.”

“THIO was effective in the majority of human and mouse glioma cell lines with no apparent toxicity against normal astrocytes. As a monotherapy, THIO demonstrated efficacy in multiple glioma cell lines that had acquired resistance to the current state-of-the art care temozolomide (TMZ). THIO induced apoptosis in several human glioma cell lines that grow as three-dimensional tumor mass-mimicking neurospheres,” said MAIA’s Chief Scientific Officer Sergei Gryaznov, Ph.D. “Additionally, THIO produced telomeric DNA damage responses not only in glioma cell lines, but also in diverse human-derived tumor specimens (PDXs). In vivo, THIO significantly decreased tumor proliferation in glioblastoma xenografts and a PDX model of glioblastoma.”

The reviewed results were published in: Clin Cancer Res (2021) 27 (24): 6800–6814.

About THIO

THIO (6-thio-dG or 6-thio-2’-deoxyguanosine) is a first-in-class investigational telomere-targeting agent currently in clinical development to evaluate its activity in Non-Small Cell Lung Cancer (NSCLC). Telomeres, along with the enzyme telomerase, play a fundamental role in the survival of cancer cells and their resistance to current therapies. The modified nucleotide 6-thio-2’-deoxyguanosine (THIO) induces telomerase-dependent telomeric DNA modification, DNA damage responses, and selective cancer cell death. THIO-damaged telomeric fragments accumulate in cytosolic micronuclei and activates both innate (cGAS/STING) and adaptive (T-cell) immune responses. The sequential treatment with THIO followed by PD-(L)1 inhibitors resulted in profound and persistent tumor regression in advanced, in vivo cancer models by induction of cancer type–specific immune memory. THIO is presently developed as a second or later line of treatment for NSCLC for patients that have progressed beyond the standard-of-care regimen of existing checkpoint inhibitors.

MAIA BIOTECHNOLOGY ANNOUNCES FDA CLEARANCE OF IND APPLICATION FOR THIO, A FIRST-IN-CLASS TELOMERE TARGETING AGENT FOR THE TREATMENT OF NON-SMALL CELL LUNG CANCER

CHICAGO–(BUSINESS WIRE)– MAIA Biotechnology, Inc. (NYSE American: MAIA), a clinical stage company developing telomere-targeting immunotherapies for cancer, today announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for THIO to be evaluated in the U.S. as part of THIO-101, the Company’s ongoing global phase 2 clinical study in patients with advanced Non-Small Cell Lung Cancer (NSCLC). THIO is being tested in sequential combination with Regeneron’s anti PD-1 monoclonal antibody cemiplimab (Libtayo®) to evaluate anti-tumor activity and immune response in NSCLC patients.

“We are extremely pleased to obtain clearance to extend our go-to-market THIO-101 trial to the U.S. and further develop THIO’s global reach,” said Vlad Vitoc, MAIA’s Chief Executive Officer.

“The FDA IND clearance represents an essential milestone in the clinical development of THIO, as a first-in-class telomere targeting agent in clinical development for patients with advanced NSCLC,” said Mihail Obrocea, M.D., MAIA’s Chief Medical Officer.

“We worked diligently with the FDA throughout the pre-IND/IND process to successfully align with their regulatory guidance and recommendations and we remain committed to developing novel, safe and effective treatments for patients with cancer,” added K. Robinson Lewis, MAIA’s Head of Regulatory and Quality.

About Investigational New Drug Application

An Investigational New Drug (IND) application is a request for authorization from the U.S. Food and Drug Administration to administer an investigational drug or biological product to humans in the United States. Organizations can initiate a clinical trial in the U.S. with IND clearance from the FDA.

About THIO

THIO (6-thio-dG or 6-thio-2’-deoxyguanosine) is a first-in-class investigational telomere-targeting agent currently in clinical development to evaluate its activity in Non-Small Cell Lung Cancer (NSCLC). Telomeres, along with the enzyme telomerase, play a fundamental role in the survival of cancer cells and their resistance to current therapies. The modified nucleotide 6-thio-2’-deoxyguanosine (THIO) induces telomerase-dependent telomeric DNA modification, DNA damage responses, and selective cancer cell death. THIO-damaged telomeric fragments accumulate in cytosolic micronuclei and activates both innate (cGAS/STING) and adaptive (T-cell) immune responses. The sequential treatment with THIO followed by PD-(L)1 inhibitors resulted in profound and persistent tumor regression in advanced, in vivo cancer models by induction of cancer type–specific immune memory. THIO is presently developed as a second or later line of treatment for NSCLC for patients that have progressed beyond the standard-of-care regimen of existing checkpoint inhibitors.

About THIO-101, Phase 2 Clinical Trial

THIO-101 is a multicenter, open-label, dose finding Phase 2 clinical trial. It is the first trial designed to evaluate THIO’s anti-tumor activity when followed by PD-(L)1 inhibition. The trial is testing the hypothesis that low doses of THIO administered prior to Regeneron’s anti-PD1 cemiplimab (Libtayo®) will enhance and prolong immune response in patients with advanced NSCLC who previously did not respond or developed resistance and progressed after first-line treatment regimen containing another checkpoint inhibitor. The trial design has two primary objectives: (1) to evaluate the safety and tolerability of THIO administered as an anticancer compound and a priming immune activator and (2) to assess the clinical efficacy of THIO using Overall Response Rate (ORR) as the primary clinical endpoint. For more information on this Phase II trial, please visit ClinicalTrials.gov using the identifier NCT05208944.

Partnership with Regeneron

• Clinical supply agreement: Regeneron provides Libtayo® for THIO-101

• Equivalent to $32M non-dilutive participation (largest financing move to date)

• Potentially expand existing relationship and target new companies

Strong and Growing IP Portfolio

• Potential for receiving NCE marketing exclusivity; 5 patents issued, 12 patent applications pending

Next Generation Potential Telomere Targeting Therapeutics • 84 new molecules engineered in last 12

months; Same mechanism of action as THIO • MAIA-2021-020, MAIA-2022-012 and

MAIA-2021-029 significantly moreCefficacious • Follow THIO to commercial stage within 4-5 years

MAIA BIOTECHNOLOGY REPORTS SECOND QUARTER 2023 FINANCIAL RESULTS AND PROVIDES UPDATES FOR THIO-101 PHASE 2 TRIAL FOR NON-SMALL CELL LUNG CANCER

• Filed second provisional new composition of matter patent application for MAIA’s third entirely home-grown telomere-targeting molecule
• Reported 35 patients enrolled as of July 2023 in THIO-101 Phase 2 Trial
• First 2 patients dosed with THIO continue to be without documented disease progression for 12.2 and 11.5 months, and remarkably without any new anti-cancer treatment 10.2 and 8.5 months after concluding treatment with THIO, most patients only live for 3-4 months in similar heavily pretreated conditions
• Announced preliminary disease control rate (DCR) of 82%, with 9 of the first 11 patients with post-baseline scans meeting the disease control primary endpoint at first response assessment, typical DCRs are in the 25-35% range for chemotherapy
• Celebrated its 5^th anniversary since being founded on August 3^rd, 2018

CHICAGO–(BUSINESS WIRE)– MAIA Biotechnology, Inc., (NYSE American: MAIA) (“MAIA”, the “Company”), a clinical-stage biopharmaceutical company developing targeted immunotherapies for cancer, today reported financial results for the second quarter ended June 30, 2023, and provided a corporate update.

“We recently reached an important milestone in the THIO-101 phase 2 trial, with our first patients dosed in the trial crossing the 1 year mark since starting therapy with THIO followed by an immune checkpoint inhibitor, without any additional cancer treatment. These positive preliminary results align well with our preclinical data and supported a faster pace of enrollment in the last quarter in Europe as we continue to activate more sites,” said Vlad Vitoc, M.D., MAIA’s Chairman and Chief Executive Officer. “In addition to THIO, we have 3 proprietary home-grown telomere-targeting molecules patented which further expands our options to treat several cancer indications. For the second half of the year, we look forward to continue evolving in the Part B randomized efficacy/dose selection of THIO-101.”

Corporate Highlights

Reported second broad provisional patent application, nominating MAIA-2021-029 as the third new molecular candidate in MAIA’s Telomere-Targeting Molecule Program: MAIA is creating and evaluating multiple telomere-targeting compounds designed to modify the telomeric structure through the cancer cell intrinsic telomerase activity and cause the death of these cells. The studies, conducted in vitro in multiple cancer cell lines and in vivo in several pre-clinical cancer models, demonstrated the intended mechanism of action and high-level anti-cancer activity for these new molecules.

Announced updates in enrollment in THIO-101 Phase 2 clinical trial: As of July 2023, announced that 35 patients have been dosed in MAIA’s Phase 2 clinical trial, THIO-101, evaluating THIO in patients with advanced Non-Small Cell Lung Cancer (NSCLC). With the addition of sites in Hungary, Poland, and Bulgaria in March 2023, THIO-101 has rapidly increased the number of patients enrolled and dosed with THIO.

Reported positive updates on preliminary survival data for THIO-101: As of July 2023, the first 2 patients dosed with THIO continue to be alive for approximately 12.2 and 11.5 months respectively, from treatment initiation. They have remained free of disease progression for 10.2 and 8.5 months, respectively, without requiring any additional therapy.

Reported updates on disease control rates for THIO-101 Phase 2 trial for advanced Non-Small Cell Lung Cancer: As of July 2023, out of the first 11 patients with post-baseline scans, 82% (9 patients) met the disease control primary endpoint (defined as a complete response, partial response, or stable disease per RECIST 1.1) at first response assessment. In similar heavily treated NSCLC patients, typical disease control rates (DCR) are in the 25-35% range. All patients enrolled had previously failed 2 or more prior lines of treatment including an immune checkpoint inhibitor (CPI) and platinum-based chemotherapy for advanced NSCLC. No new safety analysis was conducted at the time.

Second Quarter 2023 Financial Results

Cash Position: The Company had cash totaling approximately $9.1 million as of June 30, 2023, compared to $8.2 million in cash as of June 30, 2022.

Research and Development (R&D) Expenses: R&D expenses were approximately $2.6 million for the quarter ended June 30, 2023, compared to approximately $2.1 million for quarter ended June 30, 2022. The increase was primarily related to an increase in scientific research expenses of approximately $0.44 million, an increase in payroll and bonus expenses of approximately $0.20 million related to the increased headcount of additional research and development employees, an increase in stock-based compensation costs of approximately $0.06 million and an increase of approximately $0.03 million in other expenses offset by a decrease in Clinical and Scientific research expenses of approximately $0.21 million due to less THIO-101 trial start-up fees, and a decrease in consulting of approximately $0.04 million.

General and Administrative (G&A) Expenses: G&A expenses were approximately $2.0 million for the quarter ended June 30, 2023, compared to approximately $1.3 million for the quarter ended June 30, 2022. The increase for the quarter was primarily due to an increase in other expenses of approximately $0.73 million related to the costs of operating as a public company, and an increase in payroll expense of approximately $0.13 million, offset by a decrease in stock-based compensation of approximately $0.02 million and professional fees of approximately $0.09 million.

Other Income (Expense): Other income was approximately $0.14 million for the quarter ended June 30, 2023, and other income for the quarter ended June 30, 2022 was approximately $0.14 million. The quarterly activity included a gain from the change in the fair value of the warrant liability of approximately $0.10 million offset by a reduction in the Australia research and development incentives of approximately $0.10 million and an increase in interest expense of approximately $0.002 million.

Net Income (Loss): Net loss was approximately $4.5 million for the quarter ended June 30, 2023, as compared to net loss of approximately $3.3 million for the quarter ended June 30, 2022.

About THIO

THIO (6-thio-dG or 6-thio-2’-deoxyguanosine) is an investigational telomere-targeting agent currently in clinical development to evaluate its activity in Non-Small Cell Lung Cancer (NSCLC). Telomeres, along with the enzyme telomerase, play a fundamental role in the survival of cancer cells and their resistance to current therapies. THIO is being developed as a second or later line of treatment for NSCLC for patients that have progressed beyond the standard-of-care regimen of existing checkpoint inhibitors.

About THIO-101, a Phase 2 Clinical Trial

THIO-101 is a multicenter, open-label, dose finding Phase 2 clinical trial. It is the first trial designed to evaluate THIO’s potential immune system activation effects in NSCLC patients by administering THIO in sequential combination an anti-PD1 therapy, allowing for immune activation and PD-1 sensitivity to take effect. The trial will test the hypothesis that low doses of THIO administered prior to a checkpoint inhibitor will enhance and prolong immune response in patients with advanced NSCLC who previously did not respond or developed resistance and progressed after first-line treatment regimen containing another checkpoint inhibitor. The trial design has two primary objectives: (1) to evaluate the safety and tolerability of THIO administered as an anticancer agent and a priming immune system agent (2) to assess the clinical efficacy of THIO using Overall Response Rate (ORR) as the primary clinical endpoint. For more information on this Phase II trial, please visit ClinicalTrials.gov using the identifier NCT05208944.