Oncopeptides — Share Issue/Capital Change 2020

Jun 30, 2020

Stockholm, Sweden Press release June 30, 2020

Number of shares and votes in Oncopeptides

Stockholm — June 30, 2020 — Oncopeptides AB (Nasdaq Stockholm, ONCO) today announces that the number of shares and votes in Oncopeptides has changed as a result of exercise of warrants under the company's incentive programs.

Through the exercise of warrants under the company's incentive programs, the number of outstanding shares and votes have increased by 21,266 from 61,478,417 to 61,499,683. The share capital has increased by approximately SEK 2,363 from SEK 6,830,935 to SEK 6,833,298.

For further information, please contact:

Jakob Lindberg, CEO of Oncopeptides E-mail: jakob.lindberg@oncopeptides.com Telephone: +46 8 615 20 40

Rein Piir, Head of Investor Relations at Oncopeptides E-mail: rein.piir@oncopeptides.com Cell phone: +46 70 853 72 92

The information in the press release is information that Oncopeptides is obliged to make public pursuant to the Swedish Financial Instruments Trading Act. The information was submitted for publication, through the agency of the contact persons above, on June 30, 2020 at 14.00 (CEST).

About Oncopeptides

Oncopeptides is a pharmaceutical company focused on the development of targeted therapies for difficult-totreat hematological diseases. The company is focusing on the development of the lead product candidate melflufen, a first-in-class aminopeptidase-targeting peptide-drug conjugate that rapidly delivers an alkylating payload into tumor cells. Melflufen is in development as a new treatment for the hematological malignancy multiple myeloma and is currently being tested in multiple clinical studies including the pivotal phase 2 HORIZON study and the ongoing phase 3 OCEAN study. Oncopeptides' headquarters is in Stockholm, Sweden with its U.S. headquarters in Boston, Mass. The company is listed in the Mid Cap segment on Nasdaq Stockholm with the ticker ONCO.

For more information visit www.oncopeptides.com.