Rethinking Endocrine Therapy in ER-Positive Breast Cancer

Key Takeaways

• Long‑term endocrine therapy side effects drive discontinuation
• Atossa targets breast density to lower cancer risk
• RECAST uses adaptive Bayesian design for faster DCIS insights
• Generative AI cut drug combo discovery to 130 days
• Global trials lower timelines but increase development costs

Summary

Dr. Steven Quay, CEO of Atossa Therapeutics, highlighted a new focus on tolerability and prevention in estrogen‑receptor‑positive breast cancer, where five‑year survival now exceeds 90%. Atossa is developing a next‑generation SERM that aims to reduce side‑effects while maintaining efficacy and is exploring breast density reduction as a preventive strategy. The company leverages adaptive platform trials like RECAST, which use Bayesian methods to accelerate evaluation of novel endocrine agents. Additionally, generative AI is being used to rapidly identify synergistic drug combinations, compressing years of research into months.

Pulse Analysis

The oncology landscape is shifting from merely extending survival to enhancing the lived experience of patients with ER‑positive breast cancer. As five‑year survival rates climb toward 95%, side‑effects such as joint pain and hot flashes become a primary barrier to adherence. Atossa Therapeutics is addressing this gap by engineering a selective estrogen receptor modulator that matches placebo tolerability while preserving anti‑cancer potency, and by targeting dense breast tissue—a known risk factor—to prevent tumor development before it starts.

Atossa’s RECAST platform exemplifies the next wave of trial innovation. By employing an adaptive, Bayesian framework, the multi‑arm study continuously evaluates interim data, allowing promising agents to advance while underperforming ones are dropped without waiting for a traditional endpoint. This design not only shortens timelines but also enables a collaborative, multi‑sponsor environment where each partner retains blinded access to its own data. Such efficiency is critical for DCIS, where the goal is to identify patients who might safely forgo surgery in favor of active surveillance combined with endocrine therapy.

Generative AI is further accelerating discovery, turning exhaustive pathway analyses into actionable insights within weeks. Atossa’s partnership with Insilico Medicine identified a synergistic combo of endoxifen and abemaciclib in under five months, a process that historically spanned years. While drug development costs now run into billions, AI‑driven efficiencies and adaptive trial models offer a pathway to reduce financial burdens while delivering patient‑centric therapies faster to market.