Reference Detail


Missing content? – Request curation!

Request curation for specific Genes, Variants, or PubMed publications.

Have questions, comments, or suggestions? - Let us know!

Email us at :

Ref Type abstract
Authors Molly A Taylor; Qian Zhao; David Mareska; Maria Hoh; Yevgeniy Izrayelit; Kevin Litwiler; Mark L Boys; Rich Woessner; Duncan Walker; Jennifer Diamond; James D Winkler
Title Abstract B163: Discovery and characterization of OKI-219, an orally bioavailable H1047R-mutant-selective inhibitor of PI3Ka
Abstract Text Mutations in PI3Kα lead to constitutive activation of the PI3K/AKT/mTOR pathway and are found in approximately 13% of human cancers, with the PI3KαH1047R mutation being the most common. Targeting PI3Kα in cancer is a therapeutically proven strategy, with the currently approved drug alpelisib showing clinical efficacy alone or in combination with other therapies. However, treatment with non-mutant selective PI3Kα inhibitors, such as alpelisib, is associated with significant toxicities such as hyperglycemia due to on-target inhibition of the wild-type enzyme, which often leads to dose modification or discontinuation. Therefore, there is a significant need to develop new PI3Kα-targeted therapies that can avoid or minimize on-target toxicity and improve the safety and clinical benefit for patients.  OKI-219 is a PI3KαH1047R mutant-selective inhibitor, with ~100-fold cellular selectivity for the H1047R mutation over wild-type and biochemical selectivity across a 412 kinase panel, with no other kinases showing >30% inhibition at 1 µM. In vitro, OKI-219 drives decreased phosphorylated AKT (pAKT) and decreased proliferation selectively in PI3KαH1047R mutant cell lines across several tumor types. In vivo, as a monotherapy, OKI-219 demonstrates dose-dependent antitumor activity in multiple human CDX and PDX tumor xenograft models, with regression rates up to 100% in PI3KαH1047R heterozygous (T47D) and homozygous (SUM185PE) CDX models, at doses that show no sign of the metabolic dysfunction (increased glucose or insulin) that is associated with wild-type protein inhibition. The in vivo antitumor activity correlates with pathway inhibition, measured by decreased pAKT in tumors. In addition to the monotherapy efficacy observed, OKI-219 in combination with the selective estrogen receptor degrader (SERD) fulvestrant showed significant combination benefit leading to tumor regressions in the H1047R-mutated ER+HER2- breast cancer model xxT47D, at doses where no regressions were observed with single agent treatment. These data support the hypothesis that OKI-219 will offer improved efficacy and a wider therapeutic window compared to non-mutant selective PI3Kα inhibitors. This hypothesis will be tested, as OKI-219 is moving into clinical investigation.


  • Case insensitive filtering will display rows if any text in any cell matches the filter term
  • Use simple literal full or partial string matches
  • Separate multiple filter terms with a space. Any order may be used (i. e. a b c and c b a are equivalent )
  • Filtering will only apply to rows that are already loaded on the page. Filtering has no impact on query parameters.
  • Use quotes to match on a longer phrase with spaces (i.e. "mtor c1483f")


  • Generally, the default sort order for tables is set to be first column ascending; however, specific tables may set a different default sort order.
  • Click on any column header arrows to sort by that column
  • Hold down the Shift key and click multiple columns to sort by more than one column. Be sure to set ascending or descending order for a given column before moving on to the next column.

Molecular Profile Treatment Approach
Gene Name Source Synonyms Protein Domains Gene Description Gene Role
Therapy Name Drugs Efficacy Evidence Clinical Trials
OKI-219 OKI-219 1 1
Drug Name Trade Name Synonyms Drug Classes Drug Description
OKI-219 OKI219|OKI 219 PIK3CA inhibitor 23 OKI-219 inhibits PIK3CA H1047R, which potentially results in decreased tumor cell proliferation and reduced tumor growth (Mol Cancer Ther (2023) 22 (12_Supplement): B163).
Gene Variant Impact Protein Effect Variant Description Associated with drug Resistance
Molecular Profile Indication/Tumor Type Response Type Therapy Name Approval Status Evidence Type Efficacy Evidence References
PIK3CA H1047R Advanced Solid Tumor predicted - sensitive OKI-219 Preclinical - Pdx Actionable In a preclinical study, OKI-219 decreased Akt phosphorylation and proliferation in tumor cell lines harboring PIK3CA H1047R in culture and inhibited tumor growth in cell line xenograft models and patient-derived xenograft (PDX) models (Mol Cancer Ther (2023) 22 (12_Supplement): B163). detail...