MacroGenics Inc. initiated an underwritten public offering of 4.5 million common shares.

The company plans to grant the underwriters an option to buy up to an additional 675,000 shares.

Leerink Partners, Deutsche Bank Securities and Evercore ISI are acting as joint book-running managers of the proposed offering. Stifel and Nomura are acting as lead managers.

Rockville, Md.-based MacroGenics is a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for treating cancer.