FDA Approves New Cancer Drugs from Pfizer and Loxo Oncology

FDA has approved two new chemical entities to treat cancers. On Nov. 21, 2018, the agency approved Daurismo (glasdegib) tablets from Pfizer to be used in combination with low-dose cytarabine (LDAC), a type of chemotherapy, for treating newly-diagnosed acute myeloid leukemia (AML), and on Nov. 26, 2018, it approved Vitrakvi (larotrectinib) from Loxo Oncology, a genomic-focused oncology company, for treating adult and pediatric cancer patients with a specific genetic feature, or biomarker, on their tumors.

According to Pfizer, Daurismo is the first FDA-approved inhibitor of a signaling pathway that is believed to play an essential role in embryogenesis. In adults, abnormal activation of this pathway is thought to contribute to the development and persistence of cancer stem cells, the company reports.

“As our second medicine approved in the last 14 months for patients with acute myeloid leukemia, Daurismo reinforces our commitment to delivering new medicines to patients living with some of the most difficult-to-treat cancers, especially those for which there are limited treatment options available,” said Andy Schmeltz, global president, Pfizer Oncology, in a company press release. “We are proud to now offer these patients for whom intensive chemotherapy is not an option a new oral medicine, taken in combination with low-dose chemotherapy, that may improve their chances of survival.”

“Intensive chemotherapy is usually used to control AML, but many adults with AML are unable to have intensive chemotherapy because of its toxicities. Today’s approval gives health care providers another tool to use in the treatment of AML patients with various, unique needs. Clinical trials showed that overall survival was improved using Daurismo in combination with LDAC compared to LDAC alone for patients who would not tolerate intensive chemotherapy,” said Richard Pazdur, MD, director of FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in FDA’s Center for Drug Evaluation and Research, in an agency press release.

The approval of Vitrakvi, meanwhile, is the second time FDA has approved a cancer treatment based on a common biomarker across different types of tumors rather than the location in the body where the tumor originated. According to the agency, this approval marks a new paradigm in the development of cancer drugs that are “tissue agnostic.” The drug is reported to be the first oral inhibitor of receptor tyrosine kinase (TRK) approved to treat solid tumors that have a neurotrophic receptor tyrosine kinase (NTRK) gene fusion, according to Loxo Oncology.

"Today’s approval marks another step in an important shift toward treating cancers based on their tumor genetics rather than their site of origin in the body," said FDA Commissioner Scott Gottlieb, MD, in an agency press release. "This new site-agnostic oncology therapy isn’t specific to a cancer arising in a particular body organ, such as breast or colon cancer. Its approval reflects advances in the use of biomarkers to guide drug development and the more targeted delivery of medicine.”

“The FDA approval of larotrectinib marks an important milestone in how we treat cancers that have an NTRK gene fusion-a rare driver of cancer. I have seen firsthand how treatment with larotrectinib, which is designed specifically for this oncogenic driver, can deliver clinically meaningful responses in patients with TRK fusion cancer, regardless of patient age or tumor type,” said David Hyman, MD, chief of the Early Drug Development Service at Memorial Sloan Kettering Cancer Center and a global principal investigator for a larotrectinib clinical trial, in a Loxo Oncology company press release. “We now have the first therapy approved for this genomic alteration, regardless of cancer type.”

Under a November 2017 exclusive global collaboration, Loxo Oncology is developing and will commercialize larotrectinib and another TRK inhibitor, LOXO-195, with Bayer. The companies are jointly developing the two products with Loxo Oncology leading the ongoing clinical studies as well as filing in the United States. Bayer will lead ex-US regulatory activities and worldwide commercial activities. Bayer and Loxo Oncology will co-promote the products in the US.

“TRK fusions are rare but occur across many different tumor types. In this era of precision medicine, we are delivering on Bayer’s commitment to advance the future of cancer care while providing value for patients and physicians,” said Robert LaCaze, member of the executive committee of Bayer’s Pharmaceuticals Division and head of the Oncology Strategic Business Unit at Bayer, in the company press release. “It is very rewarding to provide a therapy specifically for patients with advanced solid tumors harboring an NTRK gene fusion.”

Bayer is providing two comprehensive programs, the Vitrakvi Commitment Program and the TRAK Assist patient support program, to enable US patients to gain access to the drug.

Source: FDA and Pfizer for Daurismo approval, FDA and Loxo Oncology for Vitrakvi approval