Athenex Announces Initiation of an Oral Eribulin Investigational New Drug Development Program for Oncology Indications

• Athenex has developed a novel synthetic method for Eribulin with an excellent purity profile
  
• Athenex has developed an oral version of Eribulin based on the Orascovery program which showed good oral absorption in preclinical models
• Athenex is initiating an Investigational New Drug (IND) program for Oral Eribulin, which will be the eighth IND program in their clinical pipeline

BUFFALO, N.Y., Dec. 15, 2017 -- Athenex, Inc. (Nasdaq:ATNX), a global biopharmaceutical company dedicated to the discovery, development and commercialization of novel therapies for the treatment of cancer and related conditions, today announced that it has initiated the development of an IND preparation for Oral Eribulin. Together with four other clinical candidates in their Orascovery program and three clinical candidates from their Src kinase program, this will be the eighth IND program developed by Athenex.

The active pharmaceutical ingredient (API) is developed internally using a novel synthetic approach.

Dr. William Zuo, President of Athenex China and PolyMed, stated, “Athenex is delighted to be able to synthesize Eribulin with a novel and efficient synthetic route. We have observed an excellent purity profile with our approach. This achievement is a reflection of the innovation of our scientific team.”

Dr. Michael Smolinski, Director of Pre-clinical Operations, commented, “Athenex has shown significantly improved oral bioavailability of Eribulin when paired with the Orascovery platform, which was licensed from Hanmi Pharmaceuticals. Athenex and Hanmi continue to collaborate on expanding the utility/scope of this platform. Preclinical studies with Eribulin showed favorable oral bioavailability with a pharmacokinetic profile comprised of reduced peak drug concentration (Cmax) and longer duration of the drug within the desired plasma concentration range when compared to intravenous dosing. Based on our experience with our Oraxol program, this pharmacokinetic profile may allow Oral Eribulin to provide better efficacy and potentially a lower incidence of side effects, such as peripheral neuropathy.”

Eribulin is an anticancer drug marketed by Eisai Company under the trade name Halaven. Eribulin is also known as E7389 and ER-086526, and also carries the US NCI designation NSC-707389. It is used to treat certain patients with breast cancer and liposarcoma. It is a fully synthetic macrocyclic ketone analogue of the marine natural product halichondrin B. Eribulin is a mechanistically unique inhibitor of microtubule dynamics, binding predominantly to a small number of high affinity sites at the plus ends of existing microtubules. Eribulin also has both cytotoxic and non-cytotoxic mechanisms of action

Dr. Rudolf Kwan, Athenex’s Chief Medical Officer added, "Eribulin is approved for the treatment of metastatic breast cancer patients who have received at least two prior chemotherapy regimens for late-stage disease, including both anthracycline- and taxane-based chemotherapies. This profile, coupled with the improved pharmacokinetic profile through oral administration with the Orascovery program, will provide a number of synergistic opportunities with the other drug candidates in our clinical pipeline developed by Athenex.”

About Athenex, Inc.

Founded in 2003, Athenex, Inc. is a global clinical stage biopharmaceutical company dedicated to becoming a leader in the discovery and development of next generation drugs for the treatment of cancer. Athenex is organized around three platforms, including an Oncology Innovation Platform, a Commercial Platform and a Global Supply Chain Platform. Athenex’s Oncology Innovation Platform generates clinical candidates through an extensive understanding of kinases, including novel binding sites and human absorption biology, as well as through the application of Athenex’s proprietary research and selection processes in the lab. The Company’s current clinical pipeline is derived from two different platform technologies Athenex calls Orascovery and Src Kinase Inhibition. The Orascovery platform is based on the novel oral P-glycoprotein pump inhibitor molecule HM30181A, through which Athenex is able to facilitate oral absorption of traditional cytotoxics, which Athenex believes may offer improved patient tolerability and efficacy as compared to IV administration of the same cytotoxics. The Orascovery platform was developed by Hanmi Pharmaceuticals and licensed exclusively to Athenex for all major worldwide territories except Korea, which is retained by Hanmi. The Src Kinase Inhibition platform refers to novel small molecule compounds that have multiple mechanisms of action, including the inhibition of the activity of Src Kinase and the inhibition of tubulin polymerization during cell division. Athenex believes the combination of these mechanisms of action provides a broader range of anti-cancer activity as compared to either mechanism of action alone. Athenex’s employees worldwide are dedicated to improving the lives of cancer patients by creating more active and tolerable treatments. Athenex has offices in Buffalo and Clarence, New York; Cranford, New Jersey; Houston, Texas; Chicago, Illinois; Hong Kong; Taipei, Taiwan and multiple locations in Chongqing, China.

Forward-Looking Statement Disclaimer/Safe Harbor Statement

Except for historical information, all of the statements, expectations, and assumptions contained in this press release are forward-looking statements. Actual results might differ materially from those explicit or implicit in the forward-looking statements. Important factors that could cause actual results to differ materially include: the development stage of our primary clinical candidates and related risks involved in drug development, clinical trials, regulation, manufacturing and commercialization; our need to raise additional capital; competition; intellectual property risks; risks relating to doing business in China; and the other risk factors set forth from time to time in our SEC filings, copies of which are available for free in the Investor Relations section of our website at http://ir.athenex.com/phoenix.zhtml?c=254495&p=irol-sec or upon request from our Investor Relations Department. We assume no obligation and do not intend to update these forward-looking statements, except as required by law.

CONTACT:
Jim Polson
Tel: +1-312-553-6730
Athenex, Inc.