Genprex Granted FDA Orphan Drug Designation (ODD) for REQORSA® Immunogene Therapy for the Treatment of Small Cell Lung Cancer

 

Source:  Genprex, Inc. 8/10/2023

ODD is in addition to Three FDA Fast Track Designations

Genprex expects to dose the first patient in the­­­­ Acclaim-3 clinical trial in the fourth quarter of 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 the United States Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to the Company's lead drug candidate, REQORSA^® Immunogene Therapy (quratusugene ozeplasmid), for the treatment of small cell lung cancer (SCLC). 

In addition to ODD for the treatment of SCLC, in June 2023, the FDA granted Fast Track Designation (FTD) for 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. With ES-SCLC, the cancer has spread from one lung to the other, or to other parts of the body. Extensive-stage is the most common type of SCLC. FDA has also granted Genprex FTD for two other indications of REQORSA Immunogene Therapy, including REQORSA in combination with Tagrisso for non-small cell lung cancer (NSCLC) in patients who have progressed after Tagrisso treatment, and REQORSA in combination with Keytruda for NSCLC in patients who have progressed after Keytruda treatment.

"We are excited to receive Orphan Drug Designation from the FDA for REQORSA for patients with SCLC," said Rodney Varner, President, Chairman and Chief Executive Officer at Genprex. "This FDA Orphan Drug Designation in combination with our recently received FDA Fast Track designation underscores the great need for better treatment options for patients with SCLC,ES-SCLC and NSCLC.  We look forward to initiating the Acclaim-3 clinical trial expected in the fourth quarter of 2023 in order to bring hope of an effective new therapy to patients suffering with this life-limiting cancer."

The FDA grants ODD status to investigational therapies being developed to treat, diagnose, or prevent a rare disease or condition affecting fewer than 200,000 people in the United States. Further, ODD provides benefits to drug developers, including assistance in the drug development process, tax credits for qualified trials, waiver of certain FDA fees, and potential for seven years of post-approval marketing exclusivity.

Genprex's method of treating cancer is to  reexpress tumor suppressor genes  in cancers. Tumor suppressor genes are deleted or inactivated early in the process of cancer development. REQORSA contains a plasmid that expresses a tumor suppressor gene protein called TUSC2. Virtually 100% of small cell lung cancers have reduced or no TUSC2 protein expression, and 41% completely lack TUSC2 protein expression. Pre-clinical studies in mice suggest that re-expressing the TUSC2 protein may lead to clinical efficacy. 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.

About Acclaim-3 Clinical Trial 

The Acclaim-3 clinical trial is a Phase 1/2 open-label, dose escalation and clinical response study of maintenance therapy evaluating REQORSA in combination with Tecentriq^® in patients with ES-SCLC who did not develop tumor progression after receiving Tecentriq and chemotherapy as initial standard treatment. 

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 25^th patient enrolled and treated reaches 18 weeks of follow up.

About Genprex, Inc.
Genprex 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). Each of Genprex's three lung cancer clinical programs have received a Fast Track Designation from the Food and Drug Administration (FDA), and its SCLC program has received an FDA Orphan Drug Designation. 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 may be 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.