Flagship Pioneering announced today the launch of Etcelera, a new AI-powered drug discovery biotech emerging from stealth.
The Somerville, Massachusetts-based company combines the platform technologies of Cellarity, Etiome and Empress Therapeutics with Flagship’s proprietary AI capabilities to better understand cause-and-effect relationships in human biology, according to the company.
“It’s really an out-of-the-box, fully formed, fairly advanced player in this space of causal biology because of the heritage of the three companies that go into it,” Ad Rawcliffe, CEO of Etcelera and former CEO of Etiome, told Fierce.
Etcelera aims to leverage causal intelligence to predict and explain how biological pathways respond to disruptions, known as perturbations. In practice, the company trains its AI models on large datasets showing how cells respond to different genetic, chemical or biological interventions. By identifying these cause-and-effect relationships, the models can learn the “language of biology” that governs cellular behavior and use that knowledge to predict how cells will respond to new interventions, Rawcliffe explained.
According to Flagship, the combined platform draws on more than 20 years of data, including a foundation model trained on data from 150 million cells and more than 30 proprietary AI-powered prediction models.
“We are very interested in deploying the most advanced machine learning causal inference approaches to solving the problems of drug discovery,” Rawcliffe added.
Cellarity, founded in 2017, brings an AI foundation model trained on human cell data to identify and analyze cellular states. In June 2025, Cellarity launched a phase 1 study of its oral drug candidate CLY-124 in sickle cell disease, with a readout expected later this year or early next. The program is being advanced separately through a dedicated company.
Etiome, where Rawcliffe spent the past 10 months as CEO, contributes technology that maps how cellular disease processes evolve over time, helping identify when to intervene in complex diseases involving multiple cell types, including metabolic diseases.
Empress Therapeutics brings its industrialized Perturb-seq platform, which uses high-throughput, single-cell genomics to investigate hundreds or thousands of biological hypotheses in parallel, according to the company.
“It has become clear that the technology stack that we have has an unfair advantage actually in solving this challenge of causality in biology, and a more elegant approach than either company had on its own,” Rawcliffe said. “The time is now. It is now possible with the advance in machine learning, with the industrialization of combinatorial perturb-seq, and with the investment that's gone into these models and platforms over the last decade, bringing them together now is a unique opportunity.”
Etcelera will focus on three therapeutic areas: hematology, including preclinical programs in myelofibrosis and essential thrombocythemia; metabolism, including partnered programs in metabolic dysfunction-associated steatohepatitis (MASH); and immunology. The company also inherits Cellarity's existing collaboration with Novo in MASH.
“We see our future to be quite partnership oriented,” Rawcliffe noted. “The first thing that you'll see over the course of the next six to 12 months will be substantial business development activity as we work together with partners to advance that early stage pipeline, and also to broaden the platform applicability.”