PIKASSO-01: This study is evaluating how safe and effective targeted therapy (LOXO-783) is alone, or when given with other anti-cancer therapies (such as fulvestrant, imlunestrant, abemaciclib, paclitaxel, and aromatase inhibitors) in people with advanced breast cancer or other solid cancers with a PIK3CA H1047R mutationA Study of LOXO-783 Administered as Monotherapy and in Combination With Anticancer Therapies for Patients With Advanced Breast Cancer and Other Solid Tumors With a PIK3CA H1047R Mutation

Inclusion

• Have advanced breast cancer or another solid tumor with the presence of a phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) H1047R mutation (or other Sponsor and safety review committee (SRC)-approved, activating PIK3CA mutations other than H1047R mutation)
• Have adequate archival tumor tissue sample available or be approved by the Sponsor for enrollment if no tumor sample is available.
• Have stopped all cancer treatment and have recovered from the major side effects
• Have adequate organ function, as measured by blood tests
• Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale

• Patients must have

  • Measurable disease

    --- Patients with non-breast tumor types must have at least 1 measurable lesion

  • Non-measurable bone disease (at least 1 bone lesion in breast cancer patients only)

• For patients with an estrogen receptor (ER)+ breast cancer diagnosis:

  • If female, must be postmenopausal
  • If male, must agree to use hormone suppression

• Phase 1a:

  -- Dose escalation and backfill patients:

  • Advanced solid tumor
  • Patients may have had up to 5 prior regimens for advanced disease

• Phase 1b:

  • Part A:

    • ER+/human epidermal growth factor receptor 2 (HER2)- advanced breast cancer
    • Patients may have had up to 5 prior regimens for advanced disease ---- Prior cyclin dependent kinase (CDK)4/6 inhibitor therapy required

  • Part B:

    • ER+/HER2- advanced breast cancer
    • Patients may have had up to 2 prior regimens for advanced disease.

  • Part C:

    • ER+/HER2- advanced breast cancer

    • Patients may have had up to 5 prior regimens for advanced disease.

      ---- Prior CDK4/6 inhibitor therapy required.

    • Have a diagnosis of diabetes mellitus Type 2

  • Part D:

    • Advanced breast cancer
    • Patients may have had up to 5 prior regimens for advanced disease.

  • Part E:

    • Advanced solid tumor
    • Patients may have had up to 3 prior regimens for advanced disease advanced disease

  • Part F:

    • ER+/HER2- advanced breast cancer

    • Patients may have had up to 5 prior regimens for advanced disease

      • Prior cyclin dependent kinase (CDK)4/6 inhibitor therapy required