Roginolisib, an oral, highly selective and allosteric modulator of phosphoinositide 3-kinase inhibitor delta (PI3Kδ) in patients with uveal melanoma and advanced cancers.
Authors: Anna Maria Di Giacomo, Matteo Simonelli, Federica Santangelo, Giovanni Amato, Elena Simonetti, Jill Graham, Michael M. F. Lahn, Giusy Di Conza, Tracey Hammett, Rebeca Zorrilla, Marco Durini, Ziyang Tan, Lakshmikanth Tadepally, Petter Brodin, Mariaelena Occhipinti, Carmelo Carlo-Stella, Armando Santoro, Pavlina Spiliopoulou, T.R. Jeffry Evans, Michele Maio
Journal: Journal of Clinical Oncology (2024)

9597 Background: The highly selective, oral allosteric modulator of PI3Kδ, roginolisib (IOA-244), blocks the activity of PI3Kδ-dependent signaling, in both tumor cells and Tregs. Methods: Continuous daily dosing of roginolisib at 10, 20, 40 and 80 mg in patients (pts) with pretreated solid tumours and Follicular Lymphoma (FL) were evaluated (Part A). Part B consists of a dose confirmation cohort in uveal melanoma (UM) pts of 2 parts, B.1 and B.2. Primary objective: safety of the anticipated biologically effective dose (BED). Secondary objectives: PK; PD (e.g., inhibition of CD63 expression on basophils, changes in immune cell subsets in peripheral blood); RECIST 1.1 or Lugano-based responses; PFS and OS. Exploratory studies: phenotypic changes in circulating immune cells by mass cytometry (i.e., CyTOF); response assessments by radiomics; analysis of circulating protein signatures via Olink proteomics. Results: Part A Solid Tumour (completed): Sixteen pts were treated in 4 cohorts of 4 pts each. Pts characteristics: uveal melanoma (9/16; 56%), cutaneous melanoma (5/16; 31%) and pleural mesothelioma (2/16; 13%). Only Grade 1 and 2 AEs by CTCAE v.5 were observed, including 2 cases of transient (lasting &lt; 24 hrs) diarrhoea and 2 of AST/ALT elevation. Part A FL Cohort (completed): 8 pts were treated at 20 mg (n=4) and 80 mg (n=4). Grade 3 toxicities were transient and observed in 2/8 (25%) pts. 2/4 pts (50%) at the 80 mg had PR as per Lugano criteria. Treatment-emergent adverse events (TEAEs) did not result in study drug discontinuation, immune-related toxicity, or dose-limiting toxicity in either the solid tumor or hematological patients. UM pts (Part A and Part B)&gt;: 29 pts (Part A: 9 pts; Part B.1: 7 pts, Part B.2: 13 pts), of which 23 were treated at 80 mg QD (RP2D). Mean time on treatment: 10.7 mo (range: 1.5-39.6 mo). ORR (RECIST 1.1): PR: 1/29 (3%); SD: 21/29 (72%). Median OS for Part A: 20.8 mo (5/9 with 4 pts alive); Part B.1 20.1 (4/7 with 3 pts alive); Part B.2 not determined; 1-year OS rate: Part A 66.7%; Part B.1 71%; Part B.2 immature. Exploratory Investigations: At 3.7 mo (Cycle 5), there were 2 groups: one with SD (13/29; 45%) and the other with PD (16/29; 55%). At 6 mo, this split continued with 38% (11/29) showing SD and 62% having PD (18/29). Volumetric changes matched durable SDs while having higher sensitivity in the 15 analyzed patients. Interestingly, tumor burden reduction in mediastinal lymph nodes was indicative of SD and 70% of pts had volumetric spleen size reduction. Volumetric and radiomic changes were matched with peripheral changes in plasma proteins and immune cell changes. Conclusions: Roginolisib is well tolerated at 80 mg, demonstrates efficacy, and induces phenotypic changes in circulating immune cells. At the RP2D, the most robust anti-tumour activity was observed in FL (50% PR) and UM pts (3% PR; 72% SD). Clinical trial information: NCT04328844 .