RA Capital Management said it has raised a venture-capital fund of $308 million to target life sciences investing, according to a filing with the SEC.

The Boston-based firm said the new fund boosts private company deal capacity to about $1 billion and lifts assets under management to about $2.5 billion.

The RA Capital Nexus Fund will allow the firm to take larger positions in top investments and is expected to invest alongside RA Capital Healthcare Fund.

Investments span companies in early discovery to late clinical trials in areas such as neurology, rare disorders, oncology and cardiovascular disease. The firm also has an incubator with 19 programs in discovery and early development.

The firm includes Portfolio Managers Peter Kolchinsky and Raj Shah, and Co-Heads of Venture Josh Resnick and Andrew Levin.

The filing is available here.