Genprex Receives U.S. FDA Fast Track Designation for REQORSA® Immunogene Therapy in Combination with Tecentriq® for the Treatment of Small Cell Lung Cancer

Third FDA Fast Track Designation Further Validates the Potential of REQORSA

AUSTIN, Texas — (June 28, 2023) — Genprex, Inc. (“Genprex” or the “Company”) (NASDAQ: GNPX), a clinical-stage gene therapy company focused on developing life-changing therapies for patients with cancer and diabetes, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation (FTD) for the Company’s lead drug candidate, REQORSA® Immunogene Therapy, in combination with Genentech, Inc’s Tecentriq® in patients with extensive-stage small cell lung cancer (ES-SCLC) who did not develop tumor progression after receiving Tecentriq and chemotherapy as initial standard treatment.

In the third quarter of 2023, Genprex expects to enroll the first patient in its Acclaim-3 clinical trial, which is a Phase 1/2 dose escalation and clinical response study of maintenance therapy evaluating REQORSA in combination with Tecentriq for this patient population. The Company has previously received two other FTDs for REQORSA, for REQORSA in combination with AstraZeneca PLC’s Tagrisso® in patients with late-stage non-small cell lung cancer (NSCLC) whose disease progressed after treatment with Tagrisso, and for REQORSA in combination with Merck & Co’s Keytruda® in patients with late-stage NSCLC whose disease progressed after treatment with Keytruda.

“We are very pleased to receive a third Fast Track Designation from the FDA for REQORSA, this time for patients with ES-SCLC in combination with the checkpoint inhibitor Tecentriq,” said Rodney Varner, President, Chairman and Chief Executive Officer at Genprex. “This is another exciting achievement in our REQORSA development program, which further validates REQORSA’s potential not only in NSCLC but also in SCLC. We look forward to accelerating the clinical development of REQORSA, and potentially providing a new treatment option for patients with SCLC.”

Tumor suppressor genes are deleted or inactivated early in the process of cancer development. REQORSA contains a plasmid that expresses a tumor suppressor gene named TUSC2. Virtually 100% of small cell lung cancers express descreased amounts of TUSC2 tumor suppressor protein, and 41% completely lack TUSC2 protein expression. ES-SCLC has a very poor prognosis, with a median progression free survival (PFS) of only 5.2 months. Importantly, median PFS for patients receiving Tecentriq as maintenance therapy is only 2.6 months from the start of maintenance treatment, so there is a great need for improvement in maintenance therapy.

“This Fast Track Designation for the Acclaim-3 patient population is another validation of REQORSA’s potential to treat lung cancer,” said Mark Berger, MD, Chief Medical Officer at Genprex. “We are very excited to soon begin treating patients in the Acclaim-3 clinical trial, which positions REQORSA as a component of initial standard therapy for SCLC rather than as treatment for relapse. That will allow us to highlight the contribution of REQORSA to an earlier stage of treatment. Based on our experience in other REQORSA trials, we have reduced the Phase 1 portion of the study to two dose levels instead of the three dose levels in our Acclaim-1 and Acclaim-2 clinical trials. We believe this will shorten the Phase 1 portion of the trial.  In addition, the median PFS of only 2.6 months seen with Tecentriq maintenance treatment will also shorten the time needed to evaluate the combination of REQORSA and Tecentriq as maintenance therapy for SCLC.”

Patients in the Acclaim-3 clinical trial will be enrolled after receiving initial treatment with 3-4 cycles of carboplatin, etoposide, and Tecentriq, and achieving complete response, partial response or stable disease. They will then receive treatment with REQORSA and Tecentriq as maintenance therapy every 21 days until disease progression.

The Phase 1 dose escalation portion of the Acclaim-3 clinical trial is expected to enroll up to 12 patients at 3-5 U.S. clinical sites to determine the Maximum Tolerated Dose (MTD). If no dose limiting toxicities occur during Phase 1, then the highest dose evaluated will be the Recommended Phase 2 Dose. The Phase 2 portion of the study will then enroll approximately 50 patients at 5-10 sites. Patients will be treated with REQORSA and Tecentriq until disease progression or unacceptable toxicity is experienced.

The primary endpoint of the Phase 2 portion of the trial is to determine the 18-week progression-free survival rate from the time of the start of maintenance therapy with REQORSA and Tecentriq in patients with ES-SCLC. Patients will also be followed for survival. A Phase 2 futility analysis will be performed after the 25th patient enrolled and treated reaches 18 weeks of follow up.

FDA may award FTD if it determines that non-clinical or clinical data demonstrate the potential for a drug to address an unmet medical need for a serious or life-threatening disease or condition. This provision is intended to facilitate development and expedite review of such drugs so that a product, if approved, can reach the market expeditiously.FTD recipients may also be eligible for accelerated approval or rolling review of the recipient’s Biologics License Application (BLA) if other qualifying criteria are met. In addition, Fast Track product candidates could be eligible for priority review if supported by clinical data at the time of BLA submission.

About Genprex, Inc.

Genprex, Inc. is a clinical-stage gene therapy company focused on developing life-changing therapies for patients with cancer and diabetes. Genprex’s technologies are designed to administer disease-fighting genes to provide new therapies for large patient populations with cancer and diabetes who currently have limited treatment options. Genprex works with world-class institutions and collaborators to develop drug candidates to further its pipeline of gene therapies in order to provide novel treatment approaches. Genprex’s oncology program utilizes its proprietary, non-viral ONCOPREX® Nanoparticle Delivery System which encapsulates the gene-expressing plasmids using lipid nanoparticles. The resultant product is administered intravenously, where it is taken up by tumor cells that then express tumor suppressor proteins that were deficient in the tumor.The Company’s lead product candidate, REQORSA® (quaratusugene ozeplasmid), is being evaluated in three clinical trials as a treatment for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Both NSCLC clinical programs received a Fast Track Designation from the Food and Drug Administration. Genprex’s diabetes gene therapy approach is comprised of a novel infusion process that uses an adeno-associated virus (AAV) vector to deliver Pdx1 and MafA genes directly to the pancreas. In models of Type 1 diabetes, GPX-002 transforms alpha cells in the pancreas into functional beta-like cells, which can produce insulin but are distinct enough from beta cells to evade the body’s immune system. In a similar approach, GPX-003 for Type 2 diabetes, where autoimmunity is not at play, is believed to rejuvenate and replenish exhausted beta cells.

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Cautionary Language Concerning Forward-Looking Statements 

Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are made on the basis of the current beliefs, expectations and assumptions of management, are not guarantees of performance and are subject to significant risks and uncertainty. These forward-looking statements should, therefore, be considered in light of various important factors, including those set forth in Genprex’s reports that it files from time to time with the Securities and Exchange Commission and which you should review, including those statements under “Item 1A – Risk Factors” in Genprex’s Annual Report on Form 10-K for the year ended December 31, 2022.

Because forward-looking statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding: Genprex’s ability to advance the clinical development, manufacturing and commercialization of its product candidates in accordance with projected timelines; the timing and success of Genprex’s clinical trials and regulatory approvals; the effect of Genprex’s product candidates, alone and in combination with other therapies, on cancer and diabetes; Genprex’s future growth and financial status, including Genprex’s ability to continue to obtain capital to meet its long-term liquidity needs on acceptable terms, or at all; Genprex’s commercial and strategic partnerships, including those with its third party vendors, suppliers and manufacturers and their ability to successfully perform and scale up the manufacture of its product candidates; and Genprex’s intellectual property and licenses. 

These forward-looking statements should not be relied upon as predictions of future events and Genprex cannot assure you that the events or circumstances discussed or reflected in these statements will be achieved or will occur. If such forward-looking statements prove to be inaccurate, the inaccuracy may be material. You should not regard these statements as a representation or warranty by Genprex or any other person that Genprex will achieve its objectives and plans in any specified timeframe, or at all. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. Genprex disclaims any obligation to publicly update or release any revisions to these forward-looking statements, whether as a result of new information, future events or otherwise, after the date of this press release or to reflect the occurrence of unanticipated events, except as required by law.

Genprex, Inc.

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