Quantum Leap Healthcare Collaborative and Athenex Announce the Selection of Oral Paclitaxel plus Encequidar in Combination with dostarlimab, an anti-PD-1, in the I-SPY 2 TRIAL targeting Stage 2/3 HER2+ and HER2- Breast Cancers

Athenex’s oral paclitaxel plus encequidar is being evaluated in combination with GSK’s dostarlimab in the neoadjuvant chemotherapy setting

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SAN FRANCISCO and BUFFALO, N.Y., Sept. 08, 2020 (GLOBE NEWSWIRE) -- Quantum Leap Healthcare Collaborative (Quantum Leap) and Athenex, Inc. (Nasdaq: ATNX) announce the launch of two new study arms of the I-SPY 2 TRIAL to evaluate Athenex’s combination of oral paclitaxel plus encequidar with GSK’s dostarlimab, an investigational antibody binding PD-1, in the neoadjuvant chemotherapy setting. The goal of this study is to evaluate the safety and efficacy of oral paclitaxel plus encequidar with dostarlimab +/- carboplatin in Stage 2/3 HER2- breast cancer patients and plus trastuzumab in HER2+ patients, followed, if needed, by doxorubicin plus cyclophosphamide chemotherapy (AC) and surgical resection of breast tissue.

The primary objective is to determine whether this regimen increases the probability of pathologic complete response (pCR) over standard neoadjuvant chemotherapy alone for any of the tumor subtypes established at trial entry, and to determine the predictive probability of success in a subsequent Phase 3 trial.

The primary endpoint is to assess objective response rates, as measured by pCR. This measurement will occur after the end of therapy during pathologic assessment of residual disease. pCR is defined as no residual invasive cancer in the breast (at the time of definitive surgical resection) or in the lymph nodes (no invasive tumor as determined by hematoxylin and eosin [H&E] stain).

Secondary endpoints include safety assessments and additional information on response to be obtained by measuring the change in MRI volume before, during and after therapy in order to calculate the change in residual cancer burden (RCB) at time of pathologic assessment of residual disease.

This regimen has several innovative components including: (1) assessment of extending PD-1 blockade to HER2+, (2) an orally bioavailable investigational paclitaxel that may be more convenient and tolerable over many more cycles compared to the IV formulation, and (3) the assessment of the impact of carboplatin on efficacy across all tumor subtypes, which may drastically enhance outcomes for some patients.

“We’re very excited to enter this treatment combination into the trial,” noted Laura Esserman, MD, the lead investigator for the I-SPY 2 study. “We believe Athenex’s oral paclitaxel combined with encequidar will be much easier for patients, may be more tolerable, and in combination, improve the chance of complete response, which is our goal.  We are looking to test combinations that have greater efficacy and less toxicity.  Importantly, I-SPY 2 allows us to determine which combinations work best for patients based on tumor biology. The change to an oral taxane backbone is a very important step to reducing toxicity for all patients.”