Beam Therapeutics, the company launched last year by gene editing pioneers to develop treatments through base editing, said today it completed a $135 million Series B financing, bringing its total capital raised to $222 million in less than a year.
Beam said it will use proceeds from the financing to advance its development of next-generation CRISPR technologies, expand its pipeline of base editing programs, and further extend its scientific and technical leadership.
“With this funding, we will continue to expand our team and capabilities, extend our leadership position in base editing technology, and move our pipeline towards clinical development where we hope to make an impact for patients with serious genetic diseases,” Beam CEO John Evans said in a statement.
The Series B attracted several new investors that included GV, the venture capital arm of Alphabet launched as Google Ventures in 2009—as well as Redmile Group, Cormorant Asset Management, Altitude Life Science Ventures, and additional undisclosed investors. Also participating were existing investors that included F-Prime Capital, ARCH Venture Partners, Eight Roads Ventures, and Omega Funds.
F-Prime and ARCH led the $87 million Series A financing with which Beam launched last year. That financing was large enough for the company to rank No. 4 among top private companies within GEN’s A-List of “Top 10 Companies Leveraging Gene Editing,” published in August 2018.
“Since the launch of Beam last year, we have made significant progress toward our goal of developing base editors as a new class of precision genetic medicines,” Evans said. “We now have 10 active programs underway and have expanded our team to more than 70 employees.”
Based in Cambridge, MA, Beam says its foundational technologies can edit the genome at the level of a single letter—A, G, C, or T—without cutting DNA or RNA strands. The company notes that more than half of the genetic errors associated with disease result from a single-letter change in the billions of nucleobases or “bases” forming the human genome.
The company applies CRISPR base-editing technology to make permanent, specific edits to single bases in DNA and RNA. By precisely modifying the genome to eliminate errors or write in protective changes, Beam reasons, its novel approach to base editing may underpin new treatments for a wide range of diseases.
Correcting liver disease genes
While Beam has not disclosed details of its treatment pipeline, the company’s website includes a study published on October 8, 2018 in Nature Medicine by Swiss researchers in which base editing technology corrected genes associated with a metabolic liver disease—the adult phenotype of the phenylalanine hydroxylase (Pah)enu2 mice, a model for the human autosomal recessive liver disease phenylketonuria (PKU).
The researchers engineered and validated an intein-split base editor, which allows splitting of the fusion protein into two parts, thereby circumventing the limited cargo capacity of adeno-associated virus (AAV) vectors.
“Our findings suggest that targeting genetic diseases in vivo using AAV-mediated delivery of base-editing agents is feasible, demonstrating potential for therapeutic application,” the authors concluded.
David R. Liu, PhD, of the Broad Institute of Harvard and MIT, as well as Harvard University and the Howard Hughes Medical Institute., co-founded Beam along with CRISPR pioneer Feng Zhang, PhD, and Keith Joung, MD, PhD, of Massachusetts General Hospital and Harvard Medical School.
Liu joined Holly A. Rees, PhD, of the Broad Institute of MIT and Harvard in reviewing base editing technologies—and acknowledging challenges to their use in therapeutics—in a review article published October 15, 2018, in Nature Reviews.
“Although early examples of in vivo base editing are very encouraging, challenges associated with delivery of large proteins into specific tissues remain an important focus of ongoing efforts, including the use of base editing to treat human genetic diseases. Thus, the development of novel base editor delivery systems, including those that target specific tissues, is likely to be another major focus in the coming years,” Liu and Rees cautioned.
“Detailed analyses of the off-target editing activities of base editors in vivo under a variety of conditions relevant to ongoing research and therapeutic applications are also needed,” Liu and Rees added, “as are assessments of the potential biological consequences of making off-target point mutations in vivo.”
[March 8: This updated report corrects an earlier version that omitted the names of the company’s co-founders.]