Athenex Meets With FDA Over Concerns
Athenex has had its long-awaited meeting with the federal Food and Drug Administration in its effort to bring oral paclitaxel and encequidar to market.
The company, which is nearing completion on a plant in Dunkirk, met with federal officials to discuss the deficiencies raised in the Complete Response Letter received in February.
FDA officials had been concerned of a safety risk to patients using oral paclitaxel and encequidar. The FDA also expressed concerns regarding the uncertainty over the results of the primary endpoint of objective response rate at week 19 conducted by blinded independent central review. FDA officials said in February that Athenex should conduct a new clinical trial in a patient population with metastatic breast cancerrepresentative of the population in the U.S. That prompted Athenex to seek the meeting with FDA officials, with company officials saying Athenex had performed clinical trials in accordance with FDA guidelines.
In a news release, Athenex officials said they provided the FDA additional analyses, including overall survival data on patient subgroups, which helped provide a more comprehensive summary of the risk/benefit assessment. Athenex also proposed to collect additional OS data that could inform the design of a new clinical study.
Company officials said the FDA was supportive and encouraged Athenex to continue development of oral paclitaxel and encequidar for the treatment of metastatic breast cancer. The FDA also agreed that a well-designed and well-conducted trial may adequately address the deficiencies raised in the February letter.
Athenex is evaluating the optimal design for a new clinical study which it intends to present to the FDA in the fourth quarter of 2021.
“We appreciate the FDA’s support for the development of oral paclitaxel and encequidar in this meeting and expect to maintain a collaborative dialogue on this program,” said Dr. Rudolf Kwan, chief medical officer of Athenex. “We continue to believe that, if approved, oral paclitaxel and encequidar has the potential to address a major unmet need in metastatic breast cancer. We hope to agree on a program that is capital efficient and will result in value creation for our stakeholders.”
Release of the Complete Response Letter in February led Athenex’ stock to lose value and opened the company up to a class action lawsuit being filed earlier this year.
Athenex is also developing oral paclitaxel and encequidar for the treatment of cutaneous angiosarcoma, for which it has received Orphan Drug Designation from the FDA. Athenex also received Orphan Designations from the European Commission for oral paclitaxel and encequidar for the treatment of soft tissue sarcoma.
Earlier this month, Athenex’ partner, Almirall, has received approval from the European Commission to market Klisyri® (tirbanibulin), for the topical treatment of actinic keratosis of the face or scalp in adults. Almirall launched Klisyri in the U.S. in February and will be launching the product in Europe.
Actinic keratosis or solar keratosis is a chronic and precancerous skin disease that occurs primarily in areas that have been exposed to ultraviolet radiation for a long period of time. It is usually found on the face, ears, lips, bald scalp, forearms, the posterior part of the hands, and lower legs. It is not possible to predict which AK lesions will develop into squamous cell carcinoma. AK is the most common pre-cancerous dermatological condition
Klisyri, Athenex officials said, represents a step forward in the treatment of actinic keratosis due to its short treatment protocol — one application daily for five days — proven efficacy, and safety profile.
“This approval by the European Commission marks another significant milestone for Klisyri, shortly following the marketing approval and launch of Klisyri in the U.S.,” said Dr. Johnson Lau, chief executive officer of Athenex. “We are delighted that physicians and patients across Europe can now have access to a new important treatment option for the AK indication, that has a short treatment duration and good tolerability.”
Actinic keratosis s one of the most common diagnoses in dermatology practices and the reported prevalence in the European population is around 18%, according to company officials. Treatment is a critical aspect in the management of the disease as it may progress to invasive skin squamous cell carcinoma.
In December 2020, Athenex received approval from the U.S. Food and Drug Administration for the commercialization of Klisyri in the U.S. for the topical treatment of actinic keratosis of the face or scalp. Almirall led the U.S. launch of Klisyri in February and is leading the launch of Klisyri in Europe. Under the terms of the license agreement with Almirall, Athenex is eligible to receive up to $45 million in milestone payments associated with launch and expansion into additional indications. Athenex is also eligible to receive additional sales-related milestone payments. The terms of the agreement included tiered royalties payable to Athenex starting at 15%, based on annual net sales.
In addition, Almirall has submitted Klisyri for a marketing authorisation in Switzerland and the dossier is currently under review by Swissmedic. Almirall has also made a submission in Great Britain via the European Commission Decision Reliance Procedure.