Oncternal Therapeutics

aka Oncternal Therapeutics, Inc., GTx, NASDAQ:ONCT

Oncternal Therapeutics is a San Diego biotech that developed the ROR1 antibody zilovertamab, licensed to Merck as an antibody-drug conjugate, and TK216, a small molecule against the EWS-FLI1 fusion that drives Ewing sarcoma.

Oncternal Therapeutics, formed by the 2019 merger with GTx, developed zilovertamab (cirmtuzumab), a ROR1 antibody studied with ibrutinib in mantle cell lymphoma and chronic lymphocytic leukaemia; the antibody became the basis of Merck's antibody-drug conjugate zilovertamab vedotin. TK216, an inhibitor of the EWS-FLI1 oncoprotein, was tested with vincristine in relapsed Ewing sarcoma. Its later programmes were a ROR1 CAR-T and the androgen receptor antagonist ONCT-534; in 2025 the company discontinued development and moved to wind down.

Headquarters

San Diego, California, US

Scorecard

All companies

#441of 1181 companies, score 5

phase 1/2 +1
targets +2
modalities +2

0 approved, 0 in phase 3, 1 earlier, 1 targets, 0 registry studies. Formula on the scorecards page.

Type

biotech · NASDAQ:ONCT

Stage

Public

Website

www.oncternal.com/

Products

1top

Phase 2Small-molecule EWS-FLI1 inhibitor

TK216

TK216 was an attempt to hit the fusion protein that causes Ewing sarcoma directly, something long thought impossible for a transcription factor. In early trials with vincristine it produced a few responses but not enough to carry the drug forward.

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