JAK PROTAC (SJ-19-0047)

St. Jude Reference #SJ-19-0047


Researchers at St. Jude have developed small molecule conjugates of JAK1/JAK2 inhibitor binders, which can be used for development of the treatment of CRLF2r and JAK-STAT driven ALL. CRLF2-rearranged ALL comprises up to 60% of Philadelphia-like (Ph-like, BCR ABL1-like) acute lymphoblastic leukemia (ALL), and up to 15% of B-ALL overall, and is associated with high risk features and poor outcome. Targeting of this pathway with type I JAK inhibitors such as ruxolitinib results in variable inhibition of signaling and proliferation in vivo, and emerging clinical data indicate suboptimal responses to ruxolitinib. Thus, new approaches to abrogate JAK-STAT signaling are urgently required to improve the dismal outcomes for CRLF2r ALL patients and may have broader therapeutic application in other JAK-STAT driven malignancies.

The researchers have advanced their studies to include several PROTACs based on multiple compounds and modified analogs (Ruxolitinib, Creblon, Baricitinib; and other conjugates), with 1,000x higher efficacy and improved results.


Small molecule, JAK1/JAK2 inhibitor binders, CRLF2r and JAK-STAT driven ALL, Ruxolitinib, Creblon, Baricitinib.

Granted patents or published applications

A pending patent application published as WO 2021/022076

Related scientific references

Chang, et al., “Degradation of Janus kinases in CRLF2 -rearranged acute lymphoblastic leukemia,” Blood (2021) 138 (23): 2313–2326.
DOI: https://doi.org/10.1182/blood.2020006846

More: https://ashpublications.org/blood/article/138/23/2301/482861/Degrading-JAK2-in-ALL-by-ruxolitinib-based-PROTACs

Licensing opportunities

We are seeking a partner who would develop this technology and commercialize and offer the resulting drugs.

Contact the Office of Technology Licensing (Phone: 901-595-2342, Fax: 901-595-3148) for more information.