NeoTX will present initial phase IIa results from the study of naptumomab in second/third line NSCLC at ASCO. 38 patients were included, of which 32 were evaluable for efficacy. Patients were pre-treated with obinutuzumab, which resulted in a very good safety profile for naptumomab. The overall response rate (ORR) was 16% and the disease control rate was 72%. Median overall survival (OS) was 8 months, and mean progression-free survival (PFS ) was 4.6 months. The mean duration of response was 7.3 months. Overall, we find these results inconclusive.

There is one other reasonably recent study of docetaxel in the second line (Borghaei et al. 2015), although the first treatment was with platinum and not a checkpoint immune inhibitor. In that study, the median overall survival for docetaxel was 9.4 months, the median progression-free survival was 4.2 months and the ORR was 12%. We have found another study (Aucline et al. 2023) with results published in second line NSCLC, mostly using taxanes (docetaxel is a taxane) with similar results: mean OS of 8.1 months and ORR of 16%.

It is difficult to draw any conclusions about the potential added effect of naptumomab over docetaxel alone from the new results. The pseudo-progression suggests a possible immune response from naptumomab, but it is just one case. The disease control rate is good, but we judge the other numbers to be roughly in line with what you might expect from docetaxel alone. We believe further studies are needed before deciding the indication for phase IIb or phase III studies. However, NeoTX has some difficulties in attracting funding due to the geopolitical situation of Israel, where it is located. Because of this, we lower the LOA of naptumomab slightly to 10% (11%), but this does not affect our base case (SEK1.4).

Sources:

Borghaei H, Paz-Ares L, Horn L, et al. Nivolumab versus Docetaxel in Advanced Nonsquamous Non-Small-Cell Lung Cancer. N Engl J Med. 2015;373(17):1627-1639. doi:10.1056/NEJMoa1507643

Auclin E, Benitez-Montanez J, Tagliamento M, et al. Second-line treatment outcomes after progression from first-line chemotherapy plus immunotherapy in patients with advanced non-small cell lung cancer. Lung Cancer. 2023;178:116-122. doi:10.1016/j.lungcan.2023.02.002