LONDON, 14 February 2019

• Harpoon IPO has closed
• Arix retains a stake of 12.1% in Harpoon
• The new total value of Arix’s shareholding in Harpoon is £31.3 million; a £12.1 million increase on total cash invested by Arix
• Harpoon is well-positioned to play a significant role in immuno-oncology

Arix Bioscience plc (LSE:ARIX) ("Arix"), a global healthcare and life science company supporting medical innovation notes one of its portfolio companies, Harpoon Therapeutics, Inc. (NASDAQ:HARP) (“Harpoon”) a clinical-stage immunotherapy company developing a novel class of T cell engagers, has reported the closing of its initial public offering of 5,400,000 shares of common stock at a public offering price of $14.00 per share for gross proceeds of $75.6 million, before deducting underwriting discounts and commissions and offering expenses payable by Harpoon. Harpoon’s common stock began trading on the Nasdaq Global Select Market under the ticker symbol “HARP” on 8 February 2019.

Following the IPO, Arix retains a stake of 12.1% in Harpoon (amounting to 2,892,119 shares of common stock), which was valued at £31.3 million at the close of business on 13 February 2019. This represents a gain of £12.1 million on total cash invested in Harpoon by Arix.

A registration statement relating to these securities has been filed with the Securities and Exchange Commission and was declared effective on February 7, 2019. The offering is being made only by means of a prospectus. Copies of the final prospectus relating to the offering may be obtained from: Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at (800) 831-9146; or SVB Leerink LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA 02110, by telephone at (800) 808-7525, ext. 6132, or by e-mail at syndicate@svbleerink.com.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such state or jurisdiction.

All amounts that shown are at an exchange rate of GBP 1.0000 : USD 1.2950