The proposed senior, unsecured notes will accrue interest payable semi-annually, maturing on October 1, 2033. Initial purchasers have been granted a 13-day option to acquire an additional $150 million in notes. Halozyme intends to apply a portion of the proceeds toward privately negotiated repurchases of its outstanding 2027 and 2028 convertible notes.

To mitigate potential dilution from the new issuance, the company will enter into capped call transactions with financial institutions. These hedges are designed to offset cash payments if the company's stock price exceeds the conversion price. However, the company noted that if the market price surpasses the cap price, some dilution remains possible. The final interest rate and conversion terms will be determined at the time of pricing.