SAF-189s in advanced, ALK-positive, non–small cell lung cancer: Results from a first-in-human phase 1/2, multicenter study.

9076 Background: SAF-189s is a potent, brain-penetrant, next-generation anaplastic lymphoma kinase (ALK) inhibitor with preclinical activity against most known resistance mutations of ALK. We investigated safety, population pharmacokinetics, efficacy, and antitumor activity of SAF-189s in advanced, ALK-positive (ALK+) non-small cell lung cancer (NSCLC). Methods: In this first-in-human phase 1/2 trial (NCT04237805), patients aged ≥18 years with histologically or cytologically confirmed, advanced, ALK+ NSCLC (with or without brain metastases) and an Eastern Cooperative Oncology Group performance status of 0–2 were recruited from 41 hospitals in China. Oral SAF-189s was given in escalating doses of 20–210 mg once daily in continuous, 21-day cycles until disease progression, unacceptable toxicity, consent withdrawal, or death. Phase 1 data were presented at ASCO 2020. Here, we report updated phase 1 results and preliminary phase 2 data. Results: At a clinical cutoff date of January 18, 2022, 45 patients with prior systemic therapy enrolled in phase 1 and 150 were enrolled in phase 2. SAF-189s was well tolerated, the most common grade 3–4 treatment-related adverse events were hyperglycemia (7%), hypertension (6%) and diarrhea (3%). No treatment-related death was reported. 160 mg was chosen as the recommended phase 2 dose. In phase 1, 11 (24%) patients were ALK inhibitor (ALKi)-naive and 34 (76%) were ALKi-pretreated. Median progression-free survival (PFS) was 33.1 and 22.1 months (95% CI 6.9–not reached: 13.8–26.6) in ALKi-naive and ALKi-pretreated patients, respectively. Disease control rates (DCRs) were 100% in both ALKi-naive and ALKi-pretreated patients. Most patients in phase 2 were ALKi-naive (n=104, 69%), 26 (17%) received prior crizotinib only and 20 (12%) were pretreated with ≥1 non-crizotinib ALKi. The median duration of follow-up was 11.7 months (range 10.3–16.8), ORRs were comparable between the full analysis set and the 71 patients with brain metastases at 78.7% (95% CI 71.2–84.9) and 74.6% (95% CI 62.9–84.2) respectively. ALKi-naive patients had ORR of 92.3% (95% CI 85.4–96.6), compared to 65.4% (95% CI 44.3–82.8) in the crizotinib-pretreated group. DCR was 98.1% in ALKi-naive and 88.5% in crizotinib-pretreated patients. PFS data are not mature. Conclusions: SAF-189s showed clinical antitumor activity and was well tolerated in patients with advanced, ALK+ NSCLC, including those with brain metastases and pretreated with crizotinib. SAF-189s represents a promising, next-generation, targeted therapy for patients with ALK+ NSCLC. Clinical trial information: NCT04237805. [Table: see text]