Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38650 Y-mAbs Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 47-4619612 (State or othe ...

Exhibit 99.1 Y-mAbs Reports First Quarter 2024 Financial Results and Recent Corporate Developments ● Reported U.S. DANYELZA® net product revenues of $18.6 million for the first quarter of 2024, representing a YoY increase of 11% ● Reported Worldwide DANYELZA net product revenues of $19.4 million for the first quarter of 2024, representing a 4% YoY decrease due to international volumes ● Cash and cash equivalents of $75.7 million as of March 31, 2024, and cash burn of only $2.9 million for the quarter ended ...

Y-mAbs Therapeutics, Inc. (NASDAQ:YMAB) Q4 2023 Earnings Conference Call March 1, 2024 8:00 AM ET Company Participants Courtney Dugan - Vice President, Head of Investor Relations Michael Rossi - President and Chief Executive Officer Sue Smith - Chief Commercial Officer Vignesh Rajah - Chief Medical Officer Bo Kruse - Chief Financial Officer Conference Call Participants Alec Stranahan - Bank of America David Nierengarten - Wedbush Securities Lukas Shumway - BMO Capital Markets Operator Good morning and welco ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023. OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38650 Y-mAbs Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 47-4619612 (State ...

Y-mAbs Therapeutics, Inc. (NASDAQ:YMAB) Q3 2023 Results Conference Call November 14, 2023 9:00 AM ET Company Participants Courtney Dugan - Vice President of Investor Relations Michael Rossi - President and Chief Executive Officer Thomas Gad - Chief Business Officer Bo Kruse - Chief Financial Officer Sue Smith - Chief Commercial Officer Steen Lisby - Chief Scientific Officer Conference Call Participants Alec Stranahan - Bank of America Charles Zhu - Guggenheim Bill Maughan - Canaccord Genuity Mike Ulz - Morg ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38650 Y-mAbs Therapeutics, Inc. (Exact name of registrant as specified in its charter) (State or other jurisdiction o ...

Y-mAbs Therapeutics, Inc. (NASDAQ:YMAB) Q2 2023 Earnings Call Transcript August 11, 2023 9:00 AM ET Company Participants Courtney Dugan - Head of IR Thomas Gad - Founder, President & Interim CEO Vignesh Rajah - CMO Sue Smith - CCO Bo Kruse - CFO Conference Call Participants Alec Stranahan - Bank of America Charles Zhu - Guggenheim Securities Mike Ulz - Morgan Stanley Bill Maughan - Canaccord Genuity Tessa Romero - JP Morgan Luke Shumway - BMO Capital Markets Operator Good morning, and welcome to the Y-mAbs ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38650 Y-mAbs Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 47-4619612 (State or other ...

Y-mAbs Therapeutics, Inc. (NASDAQ:YMAB) Q1 2023 Earnings Conference Call May 9, 2023 9:00 AM ET Company Participants Thomas Gad - Founder, President, Interim Chief Executive Officer Sue Smith - Senior Vice President and Chief Commercial Officer Vignesh Rajah - Senior Vice President and Chief Medical Officer Bo Kruse - Chief Financial Officer, Treasurer, and Secretary Conference Call Participants William Maughan - Canaccord Genuity Mike Ulz - Morgan Stanley Charles Zhu - Guggenheim Securities Tessa Romero - ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-38650 Y-mAbs Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 47-4619612 (State or othe ...