Oral presentation to highlight activity of REGN7075 in combination with Libtayo from dose-escalation portion of trial in patients with microsatellite stable colorectal cancer, which has historically proven unresponsive to immunotherapy

Ongoing REGN7075 Phase 1/2 trial is investigating a potentially first-in-class combination across a range of advanced solid tumors

TARRYTOWN, NY, USA I May 23, 2024 I Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced positive new results from an ongoing Phase 1/2 trial evaluating its first-in-class costimulatory bispecific antibody, REGN7075 (EGFRxCD28), in combination with Libtayo® (cemiplimab) in patients with advanced solid tumors. Data from the dose-escalation portion of the trial showed the investigational combination led to anti-tumor responses in patients with microsatellite stable colorectal cancer (MSS CRC). REGN7075 is one of the first immunotherapies to demonstrate clinical activity in MSS CRC, including in a patient with liver metastases. The results will be shared during an oral session at the American Society of Clinical Oncology (ASCO) 2024 Annual Meeting in Chicago.

“Microsatellite stable colorectal cancer has historically been unresponsive to immunotherapy,” said Neil H. Segal, M.D., Ph.D., Medical Oncologist and Research Director in the Division of Gastrointestinal Oncology at Memorial Sloan Kettering Cancer Center, and a trial investigator. “The early results for this novel investigational EGFRxCD28 costimulatory bispecific in combination with Libtayo are encouraging, showing anti-tumor responses in a highly difficult-to-treat cancer. This combination is one of the first immunotherapy regimens to show clinical activity in microsatellite stable colorectal cancer, and we are excited to advance this trial in additional tumor types.”

In the dose-escalation portion of the trial, patients with metastatic and locally advanced solid tumors – who had exhausted standard treatment options, and most of whom also had liver metastases – received combination therapy with REGN7075 and Libtayo, following a REGN7075 monotherapy lead-in dose. Among 94 patients treated as of data cutoff, 65% (n=61) had MSS CRC, of which 51 MSS CRC patients were treated at an active dose level. Efficacy results among these 51 patients were as follows:

  • 6% (n=3) overall response rate (ORR) and 29% (n=15) disease control rate (DCR). This included one complete response (CR), two partial responses (PR), and 12 patients with stable disease. At data cutoff, all responders were without liver metastases.
  • Among the subset of 15 patients without liver metastases, there was a 20% ORR (n=3) and 80% DCR (n=12).
  • Among the subset of 36 patients with liver metastases, three patients had stable disease as of data cutoff, and one patient achieved a PR following data cutoff.

Safety was assessed in 84 patients across multiple solid tumor types at a variety of doses of REGN7075. REGN7075 and Libtayo showed an acceptable safety profile, and the maximum tolerated dose was not reached. Treatment-emergent adverse events (TEAEs) of any grade occurred in 98% of patients; Grade 3 and 4 TEAEs occurred in 35% of patients. Treatment-related adverse events (TRAEs) occurred in 90% of patients, with 7% of cases reported as grade 3 or 4. The majority of TRAEs were Grade 1 to 2 (83%), with the most common being infusion-related reactions (58%) that were manageable with premedication and dosing adjustments. TRAEs led to discontinuation in 5% of patients, and three patients discontinued treatment due to Grade 2 infusion-related reactions. As of data cutoff, there have been no dose-limiting toxicities, no reports of cytokine release syndrome, and no treatment-related deaths.

“Regeneron is focused on developing a unique investigational portfolio of oncology medicines including checkpoint inhibitors, CD3 bispecifics and CD28 costimulatory bispecifics. Over the past several years, we have made progress in our programs across checkpoint inhibitors and the CD3 class and are now showing promising activity with two costimulatory bispecific antibodies,” said Israel Lowy, M.D., Ph.D., Senior Vice President, Translational and Clinical Oncology at Regeneron. “Our costimulatory bispecifics were designed with the goal of turning cancer cells into antigen presenting cells, thereby converting historically immunotherapy unresponsive tumors from ‘cold’ to ‘hot’. These early data speak to the potential of REGN7075 in combination with Libtayo and add to a growing body of evidence supporting novel costimulatory bispecifics that are in clinical trials for a range of solid tumors and blood cancers.”

The combination of REGN7075 and Libtayo is currently under clinical development, and its safety and efficacy have not been fully evaluated by any regulatory authority. While the dose escalation portion of the trial across multiple solid tumor types including non-small cell lung cancer, colorectal cancer, head and neck cancer and other tumor types is ongoing, expansion cohorts in several tumor types have also been initiated.

About the Phase 1/2 Trial
The Phase 1/2, first-in-human, open-label trial investigating REGN7075 in combination with Libtayo is currently enrolling patients with metastatic and locally advanced solid tumors who have exhausted standard treatment options. The trial includes an ongoing Phase 1 dose-escalation portion and a Phase 2 dose-expansion period. In the Phase 1 dose-escalation portion, patients first receive a weekly lead-in dose of REGN7075 monotherapy for three weeks to assess its safety and efficacy alone. This is followed by treatment with combination therapy, with Libtayo dosed once every three weeks and REGN7075 dosed either every week or every three weeks. The primary endpoints are assessing safety and tolerability, while the secondary endpoints are assessing efficacy, pharmacokinetics and immunogenicity. Expansion cohorts in several tumor types have been initiated. For more information, visit the Regeneron clinical trials website, or contact via clinicaltrials@regeneron.com or 844-734-6643.

About Regeneron in Cancer 
We aspire to turn revolutionary discoveries into medicines that can transform the lives of those impacted by cancer. Our team around the world is driven to solve the needs and challenges of those affected by one of the most serious diseases of our time.

Backed by our legacy of scientific innovation and a deep understanding of biology, genetics and the immune system, we’re pursuing potential therapies across more than 30 types of solid tumors and blood cancers. Our cancer strategy is powered by cutting-edge technologies and therapies that can be flexibly combined to investigate potentially transformative treatments for patients. Oncology assets in clinical development comprise nearly half of Regeneron’s pipeline, and include checkpoint inhibitors, bispecific antibodies and costimulatory bispecific antibodies. Our approved PD-1 inhibitor Libtayo serves as the backbone of many of our investigational combinations.

To complement our extensive in-house capabilities, we collaborate with patients, healthcare providers, governments, biopharma companies and each other to further our shared goals. Together, we are united in the mission to serve as a beacon of transformation in cancer care. 

About Libtayo
Libtayo is a fully human monoclonal antibody targeting the immune checkpoint receptor PD-1 on T cells and was invented using Regeneron’s proprietary VelocImmune® technology. By binding to PD-1, Libtayo has been shown to block cancer cells from using the PD-1 pathway to suppress T-cell activation. In the U.S. and other countries Libtayo is indicated in certain patients with advanced basal cell carcinoma (BCC), advanced cutaneous squamous cell carcinoma (CSCC) and advanced non-small cell lung cancer (NSCLC), as well as in advanced cervical cancer in the European Union, Canada and Brazil. Libtayo is developed and marketed globally by Regeneron.

In the U.S., the generic name for Libtayo in its approved indications is cemiplimab-rwlc, with rwlc as the suffix designated in accordance with Nonproprietary Naming of Biological Products Guidance for Industry issued by the U.S. Food and Drug Administration (FDA). Outside of the U.S., the generic name of Libtayo in its approved indication is cemiplimab.

The extensive clinical program for Libtayo is focused on difficult-to-treat cancers. Libtayo is currently being investigated in trials as a monotherapy, as well as in combination with either conventional or novel therapeutic approaches for other solid tumors and blood cancers. These potential uses are investigational, and their safety and efficacy have not been evaluated by any regulatory authority.

U.S. FDA-approved Indications
Libtayo is a prescription medicine used to treat:

  • People with a type of skin cancer called cutaneous squamous cell carcinoma (CSCC) that has spread or cannot be cured by surgery or radiation.
  • People with a type of skin cancer called basal cell carcinoma (BCC) when your BCC cannot be removed by surgery (locally advanced BCC) or when it has spread (metastatic BCC) and have received treatment with a hedgehog pathway inhibitor (HHI), or cannot receive treatment with a HHI.
  • Adults with a type of lung cancer called non-small cell lung cancer (NSCLC).
    • LIBTAYO may be used in combination with chemotherapy that contains a platinum medicine as your first treatment when your lung cancer has not spread outside your chest (locally advanced lung cancer) and you cannot have surgery or chemotherapy with radiation, or your lung cancer has spread to other areas of your body (metastatic lung cancer), and your tumor does not have an abnormal “EGFR,” “ALK,” or “ROS1” gene.
    • LIBTAYO may be used alone as your first treatment when your lung cancer has not spread outside your chest (locally advanced lung cancer) and you cannot have surgery or chemotherapy with radiation, or your lung cancer has spread to other areas of your body (metastatic lung cancer), and your tumor tests positive for high “PD-L1,” and your tumor does not have an abnormal “EGFR,” “ALK,” or “ROS1” gene. 

Please see full Prescribing Information, including Medication Guide.

About Regeneron’s VelocImmune Technology
Regeneron’s VelocImmune technology utilizes a proprietary genetically engineered mouse platform endowed with a genetically humanized immune system to produce optimized fully human antibodies. When Regeneron’s co-Founder, President and Chief Scientific Officer George D. Yancopoulos was a graduate student with his mentor Frederick W. Alt in 1985, they were the first to envision making such a genetically humanized mouse, and Regeneron has spend decades inventing and developing VelocImmune and related VelociSuite® technologies. Dr. Yancopoulos and his team have used VelocImmune technology to create a substantial proportion of all original, FDA-approved or authorized fully human monoclonal antibodies. This includes REGEN-COV® (casirivimab and imdevimab), Dupixent® (dupilumab), Libtayo®, Praluent® (alirocumab), Kevzara® (sarilumab), Evkeeza® (evinacumab-dgnb), Inmazeb® (atoltivimab, maftivimab and odesivimab-ebgn) and Veopoz® (pozelimab-bbfg).

About Regeneron 
Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases. 

Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite®, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases.
For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or X.

SOURCE: Regeneron Pharmaceuticals