Amgen's Investigational Targeted Treatment Bemarituzumab Granted Breakthrough Therapy Designation

Potential First-in-Class Therapy for a Subset of Gastric and Gastroesophageal Cancers That Overexpress Fibroblast Growth Factor Receptor 2 (FGFR2b)
Designation is Supported by Results From the Phase 2 FIGHT Trial

THOUSAND OAKS, Calif., April 19, 2021 /PRNewswire/ -- Amgen (NASDAQ:AMGN) today announced that the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy Designation for investigational bemarituzumab as first-line treatment for patients with fibroblast growth factor receptor 2b (FGFR2b) overexpressing and human epidermal growth factor receptor 2 (HER2)-negative metastatic and locally advanced gastric and gastroesophageal (GEJ) adenocarcinoma in combination with modified FOLFOX6 (fluoropyrimidine, leucovorin, and oxaliplatin), based on an FDA-approved companion diagnostic assay showing at least 10% of tumor cells overexpressing FGFR2b.

"The FIGHT trial is the first study to evaluate targeting the overexpression of FGFR2b in cancer. Bemarituzumab demonstrated clinically meaningful outcomes in key endpoints for patients with advanced gastric or gastroesophageal cancer as a frontline therapy," said David M. Reese, M.D., executive vice president of Research and Development at Amgen. "Amgen looks forward to further investigating the role of FGFR2b and will continue to work with regulatory agencies on next steps to bring this potential first-in-class, frontline therapy to patients."

More than one million new gastric cancer cases are diagnosed annually, and gastric cancer is particularly prevalent in Asia.^1,2 Approximately 80 to 85% of patients with advanced gastric and GEJ cancers are HER2-negative, and approximately 30% of these patients present with FGFR2b overexpression.^3,4

Following sotorasib, bemarituzumab is the second asset in Amgen's oncology portfolio to receive Breakthrough Therapy Designation in the past six months. A Breakthrough Therapy Designation is designed to expedite the development and regulatory review of medicines that may demonstrate substantial improvement on a clinically significant endpoint over available medicines.⁵

The FIGHT trial evaluated bemarituzumab plus chemotherapy (mFOLFOX6) versus chemotherapy alone in patients with FGFR2b+, non-HER2 positive frontline advanced gastric or GEJ cancer. In the study, treatment with bemarituzumab plus chemotherapy demonstrated clinically significant and substantial improvements in the primary endpoint of progression-free survival (PFS) and secondary endpoint of overall survival (OS) in the patient population in which at least 10% of tumor cells overexpressed FGFR2b. Additional analysis showed a positive correlation between benefit and the prevalence of FGFR2b+ tumor cells, affirming both the importance of the FGFR2b target and the activity of bemarituzumab against this target.  The Breakthrough Therapy Designation was granted based upon this subset of patients who showed at least 10% of tumor cells overexpressing FGFR2b.

Amgen acquired Five Prime Therapeutics on April 16, 2021. In addition to bemarituzumab, Five Prime's pipeline complements Amgen's efforts to bring innovative therapies to oncology patients.

About Bemarituzumab
Bemarituzumab (anti-FGFR2b) is a potential first-in-class investigational targeted antibody that is designed to block fibroblast growth factors (FGFs) from binding and activating FGFR2b, inhibiting several downstream pro-tumor signaling pathways and potentially slowing cancer progression. Bemarituzumab is being developed in gastric and GEJ cancer as a targeted therapy for tumors that overexpress FGFR2b. The company is also evaluating the potential for bemarituzumab in other cancers that overexpress FGFR2b.

Zai Lab (Shanghai) Co. Ltd. was granted an exclusive license to develop and commercialize bemarituzumab in Greater China, and Zai Lab collaborated with Five Prime on the Phase 2 FIGHT trial in Greater China.

About Amgen Oncology
Amgen Oncology is searching for and finding answers to incredibly complex questions that will advance care and improve lives for cancer patients and their families. Our research drives us to understand the disease in the context of the patient's life – not just their cancer journey – so they can take control of their lives.

For the last four decades, we have been dedicated to discovering the firsts that matter in oncology and to finding ways to reduce the burden of cancer. Building on our heritage, Amgen continues to advance the largest pipeline in the Company's history, moving with great speed to advance those innovations for the patients who need them.

At Amgen, we are driven by our commitment to transform the lives of cancer patients and keep them at the center of everything we do.

To learn more about Amgen's innovative pipeline with diverse modalities and genetically validated targets, please visit AmgenOncology.com. For more information, follow us on www.twitter.com/amgenoncology.

About Amgen
Amgen is committed to unlocking the potential of biology for patients suffering from serious illnesses by discovering, developing, manufacturing and delivering innovative human therapeutics. This approach begins by using tools like advanced human genetics to unravel the complexities of disease and understand the fundamentals of human biology.

Amgen focuses on areas of high unmet medical need and leverages its expertise to strive for solutions that improve health outcomes and dramatically improve people's lives. A biotechnology pioneer since 1980, Amgen has grown to be one of the world's leading independent biotechnology companies, has reached millions of patients around the world and is developing a pipeline of medicines with breakaway potential.

For more information, visit www.amgen.com and follow us on www.twitter.com/amgen.