Testing STX-478 for advanced solid tumors and breast cancer

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study evaluates the safety and effectiveness of STX-478, both alone and in combination with other cancer treatments, in patients with advanced solid tumors, particularly those with specific genetic mutations. It consists of three parts: the first part assesses STX-478 as a standalone treatment, the second part examines its use alongside fulvestrant for hormone receptor-positive breast cancer, and the third part explores its combination with endocrine therapies and CDK4/6 inhibitors. Each participant will undergo a screening period followed by treatment over a defined timeframe.

Why it matters

Who can join: the full rules

Key Inclusion Criteria:

* Has an advanced or refractory solid tumor malignancy that is metastatic or locally advanced and unresectable (as specified by Cohort)
* Has a new or recent tumor biopsy (collected at screening, if feasible) or will provide an adequate tissue sample prior to screening
* Has a tumor that harbors a documented PI3Kα mutation (cohort specific criterion for cohort-specific mutation types)
* Is ≥18 years of age at the time of signing the ICF
* Has an ECOG performance status score of 0 or 1 at screening
* Has adequate organ function as defined per protocol

Key Exclusion Criteria:

* Has history (within ≤2 years before screening) of a solid tumor or hematological malignancy that is histologically distinct from the cancers being studied
* Has symptomatic brain or spinal metastases
* Has an established diagnosis of uncontrolled diabetes mellitus (defined as HbA1c ≥8% and/or FBG ≥140 mg/dL \[7.7 mmol/L\] and/or requiring or required insulin).
* Has had prior treatment with PI3K/AKT/mTOR inhibitor(s), except in certain circumstances
* Has had treatment with any local or systemic antineoplastic therapy or investigational anticancer agent within 14 days or 4 half-lives, whichever is longer, prior to the initiation of study treatment up to a maximum washout period of 28 days. Endocrine therapy does not require a washout period if the patient is enrolling in a cohort with the same combination endocrine therapy.
* Has toxicities from previous anticancer therapies that have not resolved to baseline levels or CTCAE grade ≤1, with the exception of alopecia and peripheral neuropathy.
* Has had radiotherapy within 14 days before the initiation of study treatment

Where it's running

• Ellison Clinic at Saint John's
  Los Angeles, California, United States Recruiting
• UCSF Medical Center at Mission Bay
  San Francisco, California, United States Recruiting
• University of Colorado Cancer Center
  Aurora, Colorado, United States Recruiting
• Moffitt Cancer Center
  Tampa, Florida, United States Recruiting
• Winship Cancer Institute, Emory University
  Atlanta, Georgia, United States Recruiting
• University of Iowa
  Iowa City, Iowa, United States Recruiting

+15 more sites. See ClinicalTrials.gov for the full list.

Study contacts

• Study coordinator: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
• Email: LillyTrials@Lilly.com
• Phone: 1-317-615-4559

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.