Gedatolisib in combination with palbociclib and endocrine therapy in women with hormone receptor-positive, HER2-negative advanced breast cancer : results from the dose expansion groups of an open-label, phase 1b study

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BACKGROUND: The PI3K-mTOR pathway is frequently dysregulated in breast cancer. Combining an inhibitor targeting all class I PI3K isoforms and mTOR complex 1 (mTORC1)-mTOR complex 2 (mTORC2) with endocrine therapy and a CDK4/6 inhibitor might provide more effective tumour control than standard-of-care therapy. To evaluate this hypothesis, gedatolisib, a pan-PI3K-mTOR inhibitor, was assessed in a phase 1b trial combined with palbociclib and endocrine therapy in patients with hormone receptor-positive, HER2-negative, advanced breast cancer. Results from the dose expansion portion of this trial are reported herein.

METHODS: This multicentre, open-label, phase 1b study recruited female patients aged at least 18 years from 17 sites across the USA with hormone-receptor-positive, HER2-negative, advanced breast cancer and an Eastern Cooperative Oncology Group performance status of 0-1. Four patient groups were studied in the dose expansion portion of the study: treatment-naive in the advanced setting (first line; group A), progression on 1-2 lines of endocrine therapy but CDK4/6 inhibitor-naive (group B); and one or more previous lines (second-line and higher) of therapy, including a CDK4/6 inhibitor (groups C and D). Gedatolisib 180 mg was administered intravenously weekly in 28-day treatment cycles for groups A-C, and on days 1, 8, and 15 for group D. Letrozole (group A), fulvestrant (groups B-D), and palbociclib (all groups) were administered at standard doses and schedules. The primary endpoint was investigator-assessed objective response rate per RECIST version 1.1 in the evaluable analysis set. This trial is completed and registered with ClinicalTrials.gov, NCT02684032.

FINDINGS: Between Dec 19, 2017, and June 19, 2019, 103 female participants were enrolled in the dose expansion groups A (n=31), B (n=13), C (n=32), and D (n=27). Median follow-up was 16·6 months (IQR 5·7-48·4) for group A, 11·0 months (7·6-16·9) for group B, 3·6 months (1·8-7·5) for group C, and 9·4 months (5·3-16·7) for group D for the primary endpoint. Gedatolisib, palbociclib, and endocrine therapy induced an objective response in 23 (85·2%; 90% CI 69·2-94·8) of 27 evaluable first-line participants (group A). In the second-line and higher setting, an objective response was observed in eight (61·5%; 90% CI 35·5-83·4) of 13 evaluable group B participants, seven (25·0%; 12·4-41·9) of 28 evaluable group C participants, and 15 (55·6%; 38·2-72·0) of 27 evaluable group D participants; this included participants with both wild-type and mutated PIK3CA tumours. The most common grade 3-4 treatment-related adverse events were neutropenia (65 [63%] of 103), stomatitis (28 [27%]), and rash (21 [20%]). Grade 3-4 hyperglycaemia was reported in six (6%) participants. 23 (22%) of 103 participants had a treatment-related serious adverse event, and there were no treatment-related deaths. Nine (9%) participants discontinued treatment because of a treatment-emergent adverse event.

INTERPRETATION: Gedatolisib plus palbociclib and endocrine therapy showed a promising objective response rate compared with the published results for standard-of-care therapies and had an acceptable safety profile.

FUNDING: Pfizer and Celcuity.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:25

Enthalten in:

The Lancet. Oncology - 25(2024), 4 vom: 26. Apr., Seite 474-487

Sprache:

Englisch

Beteiligte Personen:

Layman, Rachel M [VerfasserIn]
Han, Hyo S [VerfasserIn]
Rugo, Hope S [VerfasserIn]
Stringer-Reasor, Erica M [VerfasserIn]
Specht, Jennifer M [VerfasserIn]
Dees, E Claire [VerfasserIn]
Kabos, Peter [VerfasserIn]
Suzuki, Samuel [VerfasserIn]
Mutka, Sarah C [VerfasserIn]
Sullivan, Brian F [VerfasserIn]
Gorbatchevsky, Igor [VerfasserIn]
Wesolowski, Robert [VerfasserIn]

Links:

Volltext

Themen:

96265TNH2R
Clinical Trial, Phase I
EC 2.7.10.1
EC 2.7.11.1
G9ZF61LE7G
Gedatolisib
Journal Article
Morpholines
Multicenter Study
Palbociclib
Piperazines
Pyridines
Receptor, ErbB-2
TOR Serine-Threonine Kinases
Triazines

Anmerkungen:

Date Completed 01.04.2024

Date Revised 05.04.2024

published: Print

ClinicalTrials.gov: NCT02684032

Citation Status MEDLINE

doi:

10.1016/S1470-2045(24)00034-2

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM37037424X