8 April 2021 - - US-based biotechnology company Celcuity Inc. (NASDAQ: CELC) has entered into a global licensing agreement with US-based pharmaceutical company Pfizer Inc. (NYSE: PFE) granting Celcuity exclusive rights to Pfizer's gedatolisib, a Phase 1b pan-PI3K/mTOR inhibitor, the company said.

Gedatolisib is in clinical development for the treatment of patients with ER+/HER2-negative advanced or metastatic breast cancer.

Under the terms of the licensing agreement, Pfizer provided Celcuity with a worldwide license to develop and commercialize gedatolisib.

Celcuity paid an upfront license fee of USD 5m of cash and USD 5m of Celcuity's common stock as upfront payment. Pfizer is eligible to receive up to USD 330m of development and sales-based milestone payments and tiered royalties on potential sales.

Additional financial terms of the agreement were not disclosed.

Approximately 70%-80% of breast cancers in the United States express the estrogen receptor and are thus likely dependent on estrogen signaling to promote tumor growth.

Patients with estrogen receptor-positive /HER2- metastatic tumors typically receive endocrine therapies, such as tamoxifen, letrozole, or fulvestrant.

Most women with ER+/HER2- metastatic breast cancer ultimately develop resistance to these endocrine therapies.

One new strategy to treat metastatic ER+/HER2- breast cancer involves blocking pathways enabling partial and complete endocrine resistance by combining gedatolisib and a cyclin-dependent kinases 4 and 6 (CDK 4/6) inhibitor with existing endocrine therapy.

To evaluate the efficacy and safety of this new treatment strategy, gedatolisib is currently being evaluated in combination with palbociclib, an oral CDK 4/6 inhibitor, and either letrozole or fulvestrant in the expansion portion of a Phase 1b clinical trial in patients with ER+/HER2-negative advanced or metastatic breast cancer.

A total of 103 patients were enrolled in one of four different arms according to their prior treatment history for metastatic breast cancer.

A preliminary analysis of the objective response rates as of the January 11, 2021 data cut-off demonstrated that gedatolisib combined with palbociclib and an endocrine therapy achieved superior objective response rates relative to historical control data.

Gedatolisib was also generally well tolerated, with the majority of treatment related adverse events being Grade 1 or 2. The most common Grade 3 or 4 TRAEs were neutrophil count decrease and stomatitis.