Tests tersolisib alone and combined with other cancer drugs in advanced solid tumors
Tests tersolisib, alone or with other drugs, in adults with advanced solid tumors.
Plain-language title generated from the registry record
Registry title: First-in-Human Study of Tersolisib (STX-478) as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors
Key facts
- Where
- Erlangen, GermanySee the site
- Phase
- Phase 1/2
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with an advanced solid tumor, such as breast cancer, whose tumor has a documented PI3Kα mutation.
- Age
- 18 years or older.
- Sex
- All sexes can join.
- Disease stage
- Advanced or refractory solid tumor that has spread (metastatic) or is locally advanced and cannot be removed by surgery. Some parts look at hormone receptor positive (HR+) breast cancer.
- Earlier treatment
- People who had earlier treatment with PI3K/AKT/mTOR inhibitors cannot join, except in certain circumstances. Other cancer treatment or investigational drugs must stop at least 14 days (or 4 half-lives, whichever is longer, up to 28 days) before the trial treatment starts.
- Biomarker or test result
- The tumor must have a documented PI3Kα mutation. The mutation type depends on the cohort.
Main reasons for not taking part
- Another solid tumor or blood cancer within the last 2 years that is different from the cancers studied
- Brain or spinal metastases that cause symptoms
- Uncontrolled diabetes
- Earlier treatment with PI3K/AKT/mTOR inhibitors, except in certain circumstances
- Side effects of earlier cancer treatment that have not improved to grade 1 or lower (except hair loss and peripheral neuropathy)
Read by machine on 9 November 2026.
Where in Germany
- Universitaetsklinikum Erlangen AöRErlangen, GermanyTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Eli Lilly and Company
- Trial code
- NCT05768139EU 2023-504807-94-00
- Record updated
- 7 July 2026
- Original description
Study STX-478-101 (LY4064809) is a multipart, open-label, phase 1/2 study evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary antitumor activity of STX-478 (LY4064809) in participants with advanced solid tumors with P13Ka mutations.Read full original descriptionShow less
First-in-Human Study of STX-478, a Mutant-Selective PI3Kα Inhibitor as Monotherapy and in Combination With Other Antineoplastic Agents in Participants With Advanced Solid Tumors
Study STX-478-101 (LY4064809) is a multipart, open-label, phase 1/2 study evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary antitumor activity of STX-478 (LY4064809) in participants with advanced solid tumors with P13Ka mutations.
Part 1 will evaluate STX-478 as monotherapy in participants with advanced solid tumors. Part 2 will evaluate STX-478 therapy as combination therapy with fulvestrant in participants with hormone receptor positive (HR+) breast cancer. Part 3 will evaluate STX-478 as combination therapy with endocrine therapy (aromatase inhibitors, fulvestrant, tamoxifen, or imlunestrant) and a CDK4/6 Inhibitor (either Ribociclib, Palbociclib or Abemaciclib) in participants with HR+ breast cancer.
Each study part will include a 28-day screening period, followed by treatment with STX-478 monotherapy or combination therapy.
Inclusion: 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.
Exclusion: 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; 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 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.