First-in-Human Study of PLX-61639 in Locally Advanced or Metastatic Solid Tumors

Trial statusRecruiting
Trial phasePhase 1
Trial typeInterventional
Biological sexAll
Age18+
SponsorPlexium, Inc.

About this trial

A multicenter, single-arm, first-in-human study to investigate the safety, pharmacokinetics, and preliminary antitumor activity of PLX-61639 in participants with locally advanced or metastatic, relapsed/refractory, SMARCA4-deficient solid tumors who are intolerant of or have failed available, approved therapies.

The study will be conducted in 3 parts: dose escalation (Part 1), dose optimization (Part 2), and cohort expansion (Part 3). Each part of the study will consist of a Screening Phase lasting up to 28 days during which participants will be assessed for eligibility, a Treatment Phase beginning on Cycle 1 Day 1 and consisting of consecutive 28-day cycles, an End of Treatment Visit, and a Post-Treatment Follow-Up Phase.

Participants will receive their assigned dose of PLX-61639 administered orally, once daily until progression/relapse, intolerance, death, or withdrawal from study treatment by the Investigator or participant.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Participants with locally advanced or metastatic, relapsed/refractory, solid tumors harboring a SMARCA4 loss-of-function mutation that have progressed on, are intolerant of, or not otherwise candidates for available approved therapies

Adequate liver bone marrow, coagulation, renal, and cardiopulmonary function

Measurable disease per RECIST 1.1

ECOG PS of 0 or 1

Disqualifiers

Germline SMARCA4 mutations

Known SMARCA2 mutation or loss of expression

Symptomatic CNS disease

Prior treatment with another SMARCA2-directed therapy

Trial design

Design model

Sequential

Treatments tested in this trial

  • PLX-61639

    Drug

    Orally available degrader of SMARCA2

Treatment groups

155 Participants
are divided into 1 treatment group
Group A: PLX-61639Experimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Treatment Emergent Adverse Events

Time frame
From enrollment to 28 days after the last dose of PLX-61639
2

Dose-Limiting Toxicities

Time frame
From enrollment to 28 days after first dose of PLX-61639

Secondary outcomes

1

Dose reductions due to Adverse Events

Time frame
From Day 1 to the end of PLX-61639 treatment, an average of 1 year
2

Study treatment discontinuations for reasons other than disease progression

Time frame
From Day 1 to the end of PLX-61639 treatment, an average of 1 year
3

Pharmacokinetics of PLX-61639: Cmax

Time frame
From Day 1 to Day 15 of Cycle 1 (Part 1 only) (each cycle is 28 days)
4

Pharmacokinetics of PLX-61639: Tmax

Time frame
From Day 1 to Day 15 of Cycle 1 (Part 1 only) (each cycle is 28 days)

Other outcomes

Sponsors and contacts

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