100% overall and 80% complete response rate in 10 patients with relapsed or refractory follicular lymphoma treated with 5 mg or more of REGN1979

Plan to initiate in 2019 a potentially registrational Phase 2 trial in relapsed or refractory follicular lymphoma

Promising clinical activity also seen in ongoing study in diffuse large B-cell lymphoma

TARRYTOWN, NY, USA I December 1, 2018 I Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today presented new data for REGN1979 in patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL), including promising clinical results in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) which are the two most common types of NHL. In this Phase 1 proof-of-concept trial, REGN1979 demonstrated an acceptable safety and tolerability profile with no observed dose-limiting toxicities (DLTs). There were no clinically-significant neurotoxicities, including no occurence of seizures or encephalopathy. REGN1979 is a wholly-owned, investigational, full-length bispecific monoclonal antibody designed to trigger tumor killing by binding CD3 on immune system T-cells and CD20 on B-cell malignancies.

In the data presented at the 2018 American Society of Hematology (ASH) Annual Meeting, heavily pre-treated patients with R/R FL grades 1 to 3a who received REGN1979 doses of 5 mg to 40 mg, experienced a 100% overall response rate (ORR) (8 complete responses [CR] and 2 partial responses [PR]); 90% of responders maintained a response during treatment. Based on these data, Regeneron plans to initiate in 2019 a potentially registrational Phase 2 trial investigating REGN1979 in R/R FL.

REGN1979 also showed encouraging dose-dependent clinical activity in heavily pre-treated patients with R/R DLBCL. Among patients receiving doses between 5 mg and 12 mg, the ORR was 18% (2 of 11 patients, including 1 CR and 1 PR). At doses of 18 mg to 40 mg, the ORR increased to 60% (6 of 10 patients, including 2 CR and 4 PR). Regeneron plans to continue dose-escalation in DLBCL.

“While a high response rate is frequently observed in the first-line treatment of follicular lymphoma, it is remarkable to see a 100% response rate in heavily pre-treated relapsed or refractory follicular lymphoma patients,” said Israel Lowy, M.D., Ph.D., Head of Clinical and Translational Sciences, Oncology at Regeneron. “We plan to initiate a potentially registrational Phase 2 trial in 2019 investigating REGN1979 in relapsed or refractory follicular lymphoma, and are also considering its potential as a first-line treatment for this disease. Furthermore, we are continuing to dose-escalate in the more difficult-to-treat DLBCL setting, to see if we can continue to further improve efficacy. Finally, REGN1979 is being investigated in combination with Libtayo® (cemiplimab-rwlc) in an ongoing Phase 1 study, which we believe is the first to combine a CD20xCD3 bispecific antibody with a PD-1 or PD-L1 inhibitor.”

“There have been tremendous recent advances in the field of immuno-oncology, with new breakthrough therapies including checkpoint inhibitors and personalized cell-based therapies,” said George D. Yancopoulos, M.D., Ph.D., President and Chief Scientific Officer at Regeneron. “Regeneron has recently launched its first checkpoint inhibitor, Libtayo, for a serious skin cancer with no previously-approved therapies that were available. Regeneron is also advancing a broad and deep bispecific antibody platform – which may offer off-the-shelf alternatives to cell-based therapies for both solid tumors and hematologic malignancies. Our bispecific antibody pipeline includes REGN1979 and a MUC16xCD3 antibody for ovarian cancer in clinical development, and a BCMAxCD3 antibody for multiple myeloma expected to enter human studies before the end of this year. In 2019, we expect to start clinical trials of a new class of bispecific antibodies that engage cellular immunity in novel ways. We believe that cancer treatment in the future will require precision medicine-based combinations of these and other approaches and that Regeneron is well positioned to be a future leader in this exciting area.”

The objectives for this ongoing Phase 1 proof-of-concept trial are to assess safety, tolerability and efficacy of REGN1979 monotherapy. The data presented at ASH included a total of 68 patients with R/R B-NHL who were treated with REGN1979. These patients had received a median of three prior therapies, including an anti-CD20 therapy. As of September 2018, 14 patients had completed treatment, 13 patients remained on treatment and 41 had discontinued treatment. The most common reason for treatment discontinuation was progressive disease (27 patients). Two patients discontinued treatment due to a treatment-emergent adverse event (TEAE; grade 3 hemolysis and grade 3 fatigue).

In the trial, the most common TEAEs occurring in at least 25% of patients were pyrexia, chills, cytokine release syndrome (CRS), fatigue, increased C-reactive protein, anemia, hypotension, infusion-related reaction (IRR) and nausea. IRR and CRS events were generally mild to moderate in severity, and neither resulted in trial discontinuations. Three patients in the trial died due to adverse events. Of these, one death, in a patient with a tumor involving the gastric lining who experienced a gastric perforation, was attributed to REGN1979.

REGN1979 was invented by Regeneron using the company’s proprietary VelocImmune® technology that yields optimized fully-human antibodies, and Regeneron’s proprietary Veloci-Bi™ bispecific platform. Veloci-Bi allows for the generation of full-length bispecific antibodies similar to native antibodies that are amenable to production by standard antibody manufacturing techniques, and likely to have favorable antibody-like pharmaco-kinetic properties.

REGN1979 was granted orphan drug designation by the U.S. Food and Drug Administration for the treatment of DLBCL in 2017. REGN1979, REGN4018 (MUC16xCD3 bispecific antibody) and REGN5458 (BCMAxCD3 bispecific antibody) are currently under clinical development for B-NHL, ovarian cancer and multiple myeloma, respectively, and their safety and efficacy have not been evaluated by any regulatory authority. In addition, the potential use of REGN1979 in combination with Libtayo is investigational, and its safety and efficacy have not been evaluated by any regulatory authority.

Libtayo is being developed jointly by Regeneron and Sanofi under a global collaboration agreement. In the U.S., Libtayo is currently approved for the treatment of patients with metastatic CSCC or locally advanced CSCC who are not candidates for curative surgery or curative radiation. Regeneron and Sanofi Genzyme, the specialty care global business unit of Sanofi, market Libtayo jointly in the U.S.

About Regeneron Pharmaceuticals, Inc.
Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents life-transforming medicines for people with serious diseases. Founded and led for 30 years by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to seven FDA-approved treatments and numerous product candidates in development, all 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, neuromuscular diseases, infectious diseases and rare diseases.

Regeneron is accelerating and improving the traditional drug development process through our proprietary VelociSuite® technologies, such as VelocImmune® which produces optimized fully-human antibodies, and ambitious research initiatives such as the Regeneron Genetics Center, which is conducting one of the largest genetics sequencing efforts in the world.

SOURCE: Regeneron Pharmaceuticals