NCT02514447|CompletedPhase 1ResultsDMCFDA Drug

Trilaciclib (G1T28) in Patients With Previously Treated Extensive Stage SCLC Receiving Topotecan Chemotherapy

Phase 1b/2a Safety and Pharmacokinetic Study of G1T28 in Patients With Previously Treated Extensive Stage Small Cell Lung Cancer (SCLC) Receiving Topotecan Chemotherapy

G1 Therapeutics, Inc.ClinicalTrials.gov

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2 other identifiers

G1T28-032016-004611-13

Study Type

interventional

Target

123

Locations

7 countries

Sites

Timeline

RegisteredAug 2015

StartedOct 2015

CompletionOct 2021

Brief Summary

This was a study to investigate the potential clinical benefit of trilaciclib (G1T28), a Cyclin Dependent Kinase (CDK) 4/6 inhibitor, in preserving the bone marrow and the immune system, in order to decrease chemotherapy-induced myelosuppression and improve anti-tumor efficacy when administered prior to topotecan in patients previously treated for extensive-stage SCLC. The study consisted of 2 parts: a limited open-label, dose-finding portion (Part 1), and a randomized double-blind portion (Part 2). Both parts included 3 study phases: Screening Phase, Treatment Phase, and Survival Follow-up Phase. The Treatment Phase began on the day of first dose with study treatment and completes at the Post-Treatment Visit.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

123

participants targeted

Target at P75+ for phase_1

Timeline

Completed

Started Oct 2015

Longer than P75 for phase_1

Geographic Reach

7 countries

48 active sites

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

6 years study duration

First Submitted

Initial submission to the registry

July 31, 2015

Completed

3 days until next milestone

First Posted

Study publicly available on registry

August 3, 2015

Completed

2 months until next milestone

Study Start

First participant enrolled

October 5, 2015

Completed

3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 28, 2018

Completed

3 years until next milestone

Study Completion

Last participant's last visit for all outcomes

October 4, 2021

Completed

8 months until next milestone

Results Posted

Study results publicly available

June 9, 2022

Completed

Last Updated

September 25, 2025

Status Verified

September 1, 2025

Enrollment Period

3 years

First QC Date

July 31, 2015

Results QC Date

February 7, 2022

Last Update Submit

September 5, 2025

Conditions

Small Cell Lung Cancer

Keywords

SCLCCDK4/6 Inhibitor

Outcome Measures

Primary Outcomes (3)

Duration of Severe (Grade 4) Neutropenia in Cycle 1
Duration of severe neutropenia (DSN; days) was defined as the number of days from the date of the first ANC value of \<0.5 × 10\^9/L observed between start of cycle and end of cycle to the date of the first ANC value ≥0.5 × 10\^9/L that met the following criteria: (1) occurred after the ANC value of \<0.5 × 10\^9/L and (2) no other ANC values \<0.5 × 10\^9/L occurred between this day and end of cycle. DSN is set to 0 for patients who did not experience SN in a cycle, including those who were randomized but never treated. Data from unscheduled visits and the actual assessment date (rather than visit date) were included in the derivation.
Evaluated for Cycle 1 (i.e., from date of first dose of study drug (Part 1)/randomization (Part 2) to the end of Cycle 1, each cycle = 21 days)
Occurrence of Severe (Grade 4) Neutropenia
Number of Participants with severe (Grade 4) neutropenia (SN) was a binary variable. If a patient had at least 1 absolute neutrophil count value \<0.5 × 10\^9/L during the Treatment Period, the patient was assigned as Yes to the occurrence of SN; otherwise, it was No.
During the treatment period. From date of first dose (Part 1)/randomization (Part 2), 21 day treatment cycles continue until disease progression, unacceptable toxicity, or discontinuation by the patient or investigator (assessed up to 1090 days).
Assess the Dose Limiting Toxicities (DLTs) of G1T28/Trilaciclib Administered With Topotecan in Part 1
The percentage of patients experiencing DLTs in Part 1 of the study in each cohort, including: * Absolute neutrophil count (ANC) \< 0.5 × 10\^9/L lasting for ≥ 7 days * ≥ Grade 3 neutropenic infection/febrile neutropenia * Grade 4 thrombocytopenia or ≥ Grade 3 thrombocytopenia with bleeding * Unable to start next cycle of chemotherapy due to lack of recovery to an ANC ≥ 1.5 × 10\^9/L and platelet count ≥ 100 × 10\^9/L; a delay of up to 1 week from the scheduled start of Cycle 2 is allowed for recovery of ANC and platelet count, and is not considered a DLT * ≥ Grade 3 nonhematologic toxicity (nausea, vomiting, and diarrhea failing maximal medical management; fatigue lasting for \> 72 hours)
Evaluated for Cycle 1 (i.e., from date of first dose of study drug (Part 1) to the end of Cycle 1, each cycle = 21 days)

Secondary Outcomes (20)

Pharmacokinetic Profile for Trilaciclib (G1T28) When Administered With Topotecan
Part 1 of the study during Cycle 1 Day 4 : predose, 0.5, 1, 1.5, 2, 2.5, 3, 4.5, 6.5, 8.5 (optional), and 24.5 hours post dose. Part 2 of the study during Cycle 1 Day 4 : predose, 0.5, 1, between 3 to 4 hours and between 5.5 to 6.5 hours post dose.
Progression Free Survival (PFS)
From date of first dose of study drug (Part 1)/randomization (Part 2), until date of documented disease progression or death due to any cause (evaluated up to a maximum of 1335 days).
Overall Survival (OS)
From date of first dose of study drug (Part 1)/randomization (Part 2) until the date of death due to any cause (evaluated up to a maximum of 2220 days).
Assess the Hematologic Profile of G1T28/Trilaciclib Administered With Topotecan
During the treatment period. From date of first dose (Part 1)/randomization (Part 2), 21 day treatment cycles continue until disease progression, unacceptable toxicity, or discontinuation by the patient or investigator (assessed up to 1090 days).
Tumor Response Based on RECIST, Version 1.1
From date of first dose of study drug (Part 1)/randomization (Part 2) until the occurrence of progressive disease, withdrawal of consent, or initiation of subsequent anti-cancer therapy, (assessed up to a maximum of 1335 days).
+15 more secondary outcomes

Study Arms (9)

Placebo + Topotecan 1.5 mg/m² - Parts 2a and 2b

EXPERIMENTAL

Patients in Parts 2a and 2b were randomized 1:2 to placebo. Patients received placebo administered IV once daily on Days 1 to 5 of each 21-day topotecan chemotherapy cycle. Following administration of placebo on Days 1 to 5, patients received IV topotecan (1.5 mg/m²).

Drug: PlaceboDrug: Topotecan

Trilaciclib (G1T28) 240 mg/m² + Topotecan 0.75 mg/m² - Part 2a

EXPERIMENTAL

Patients in Part 2a were randomized 2:1 to trilaciclib. Patients received trilaciclib (240 mg/m²) administered IV once daily on Days 1 to 5 of each 21-day topotecan chemotherapy cycle. Following administration of trilaciclib on Days 1 to 5, patients received IV topotecan (0.75 mg/m²).