MacroGenics Shares Early TAMARACK Phase 2 Safety Data and Upcoming Updates

MacroGenics, Inc., a biopharmaceutical enterprise centered on the discovery and advancement of antibody-based cancer treatments, has recently shared an update on the Phase 2 TAMARACK clinical trial. This trial is assessing vobramitamab duocarmazine, a novel antibody-drug conjugate (ADC), for the treatment of metastatic castration-resistant prostate cancer (mCRPC).

The company had submitted early safety data from the TAMARACK study to the American Society of Clinical Oncology (ASCO) for an upcoming conference. However, the abstract was not accepted for presentation. Despite this, MacroGenics remains committed to sharing interim data, including safety and preliminary efficacy, by the end of May. They also plan to present additional clinical data in the Fall of 2024, with radiographic progression-free survival (rPFS) being the primary endpoint of the study.

The TAMARACK study is a randomized, open-label Phase 2 trial that is evaluating two dosages of vobramitamab duocarmazine (2.0 mg/kg and 2.7 mg/kg IV Q4W). The trial has enrolled patients with mCRPC who have previously received treatment with abiraterone, enzalutamide, or apalutamide, and prior docetaxel treatment is also permitted. The primary goal of the study is to assess the progression-free survival at six months.

As of January 4, 2024, 182 patients with mCRPC were enrolled, and 177 of them have received vobramitamab duocarmazine. The patients ranged in age from 46 to 89 years old, with a median age of 70.5 and an ECOG performance status of 2 or less. Preliminary safety data from the TAMARACK study indicates that reducing the dosage and frequency of vobramitamab duocarmazine may enhance its safety and tolerability profile in men with mCRPC.

The most common treatment-emergent adverse events (TEAEs) reported were asthenia, nausea, fatigue, decreased appetite, anemia, constipation, diarrhea, headache, neutropenia, and peripheral edema. The study's Independent Data Monitoring Committee (IDMC) recommended continuing the trial without any modifications after an interim analysis for futility on both dosage arms.

MacroGenics is dedicated to advancing its pipeline of product candidates through its suite of next-generation antibody-based technology platforms. The company's expertise in protein engineering has facilitated the development of promising therapeutic candidates and strategic collaborations with global pharmaceutical and biotechnology companies.