Phase 2 clinical trial of the proautophagic drug ABTL0812 combined with paclitaxel and carboplatin in first-line patients with advanced squamous non-small cell lung carcinoma.

Abstract

9059 Background: ABTL0812 induces the inhibition of Akt/mTOR pathway by upregulation of TRIB3 protein, an endogenous Akt inhibitor, and promotes endoplasmic reticulum (ER) stress. As a result, ABTL0812 induces cytotoxic autophagy that leads to specific death of cancer cells, without affecting non-tumor cell viability. A Phase II clinical trial was designed where ABTL0812 was evaluated in combination with paclitaxel and carboplatin in first-line patients with advanced squamous non-small cell lung cancer (NSCLC). Methods: ABTL0812 was administered 1300 mg TID orally with 175 mg/m2 paclitaxel and AUC5 carboplatin every 3 weeks, for up to 8 cycles, followed by ABTL0812 as a maintenance until disease progression or unacceptable toxicity. The study enrolled patients with non-irradiable IIIb stage or stage IV squamous NSCLC. Primary endpoint was overall response rate (ORR) by RECIST criteria v.1.1. Secondary endpoints were progression free survival (PFS), overall survival (OS), duration of response (DOR), safety and tolerability according to CTCAE v4.03, pharmacokinetics (PK) of ABTL0812 enantiomers ((-)-ABTL and (+)-ABTL) and pharmacodynamics assessed by two surrogate blood biomarkers: TRIB3 and CHOP. Results: Forty patients were included; median age was 66.1 years old; 90% men/10% women; 100% ECOG 0-1; 30% current smokers/67.5% former smokers and 37.5% had received prior chemotherapy > 12 months before inclusion. 39 patients had at least 1 adverse event (AE), anemia appeared in 32.5% of the patients (5.0% grade 3), neutropenia in 27.5% (25% grades 3-4) and thrombocytopenia in 17.5% of the patients (2.5% grade 3). For non-hematological AEs, asthenia was reported in 62.5% of the patients (2.5% grade 3); diarrhea in 45% (no grade 3-4) and nausea in 37.5% (5% grades 3-4). Twenty-five patients reach the primary endpoint for efficacy evaluation. ORR was 52.0% (95% CI 34.2-65.9) and 32.0% of the patients had stable disease. Median OS was 22.5 months (10.4-NC), median progression free survival 6.2 months (4.4-8.8), and DOR 5.1 months (3.9-7.4). Area under the curve (µg·h/ml) for (-)-ABTL and (+)-ABTL were 39.0±12.3 and 17.1±6.3 respectively, maximal concentrations (µg/ml) were 6.4±2.6 and 5.1±2.2 and minimum concentrations (µg/ml) 2.2±1.5 and 0.8±1.3. TRIB3 and CHOP PD biomarkers were induced by the treatment. Conclusions: The combination of ABTL0812 with paclitaxel and carboplatin shows survival outcomes that compare favorably with historical controls in squamous-NSCLC with an acceptable safety profile. PK analysis is compatible with drug activity, and pharmacodynamic analysis shows drug engagement. Clinical trial information: NCT03366480 .