Achillion Pharmaceuticals (NASDAQ: ACHN) shares skyrocketed by over 80% on Wednesday morning after Alexion Pharmaceuticals (NASDAQ: ALXN) agreed to acquire the Company for a cash deal valued at USD 930 Million.

Under the agreement, Alexion will acquire Achillion for approximately USD 6.30 per share. Alexion will also acquire the cash currently on Achillion’s balance sheet. The transaction includes the potential for additional consideration in the form of non-tradeable contingent value rights (CVRs), which will be paid to Achillion shareholders if certain clinical and regulatory milestones are met. This includes USD 1.00 per share for FDA approval of danicopan and USD 1.00 per share for ACH-5228 Phase 3 initiation.

Achillion is a clinical-stage biopharmaceutical company focused on the development of oral small molecule Factor D inhibitors, which is used to treat people with rare diseases such as paroxysmal nocturnal hemoglobinuria (PNH) and C3 glomerulopathy (C3G). Currently, Achillion has two clinical-stage medications in development, which includes danicopan (ACH-4471) in phase 2 and ACH-5228 in phase 1.

Similarly, Alexion is also aimed towards developing and commercializing therapies to treat patients suffering from rare diseases. Alexion has developed two approved complement inhibitors to treat patients with paroxysmal nocturnal hemoglobinuria as well as other conditions.

“Alexion has demonstrated the transformative impact that inhibiting C5 can have on multiple rare and devastating diseases. However, we believe this is just the beginning of what’s possible with complement inhibition,” said Ludwig Hantson, Ph.D., Chief Executive Officer of Alexion.

“We look forward to applying our nearly three decades of complement and development expertise to unlock the potential of oral Factor D inhibitors and bring these benefits to patients.” concluded Hantson.

The transaction is expected to close in the first half of 2020.