ALK V1180L

We present a female advanced non-small cell lung cancer (NSCLC) case with positive EML4-ALK gene fusion, in which disease progression occurred in only 3 months after first-line treatment with alectinib...Ensartinib and ceritinib were administered as second-line and third-line treatments...The secondary mutation E803Q located in exon 14 seems resistant to most second-generation ALK-TKIs. If there is an opportunity, the efficacy of the third-generation ALK-TKI loratinib should be tested.

This study affirms the efficacy of lorlatinib in patients with ALK-positive SCLC transformation harboring the V1180L mutation. Furthermore, it underscores the imperative of conducting genetic testing in patients who transition to SCLC following ALK-TKI resistance, as targeted therapies may remain efficacious if a genetic driver is identified.

Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.

In Cohort 1 (n=21), 15 (71%) pts had progressed on alectinib, 5 (24%) on ceritinib and 1 (5%) on ensartinib. In Cohort 2 (n=18), pts had progressed on crizotinib followed by alectinib (n=9, 50%), ceritinib (n=4, 22%) or brigatinib (n=3, 17%); 2 (11%) pts progressed on crizotinib, then ceritinib followed by alectinib...Of 5 pts with ALK resistance mutations (I1171N, V1180L, L1196M, G1202R, and E1210K) who subsequently received lorlatinib, repeat ctDNA NGS after 2 months demonstrated clearance of ALK resistance mutation(s) in 4/5 (80%) pts (i.e. undetectable on repeat testing)... Resistance mechanisms to ALK inhibitors are heterogenous, including both ALK dependent and independent pathways. DDR and cell cycle gene alterations were commonly detected and may represent previously unreported acquired resistance alterations. Comprehensive ctDNA NGS analysis at progression may help detect novel resistance alterations in patients on ALK inhibitors.

Despite early progression within 3 mo under crizotinib, a durable response was achieved with alectinib...Another rebiopsy revealed ALK:p.L1196M, but the tumor did not respond to brigatinib or carboplatin/pemetrexed, before stabilization under lorlatinib...Lorlatinib retained efficacy in the heavily pretreated setting, while its upfront use could possibly have prevented the stepwise emergence of compound ALK mutations. Furthermore, the disease course was more aggressive and OS shorter compared to the V2/TP53wt ALK+ lung adenocarcinoma, while crizotinib, ceritinib and brigatinib did not confer the benefit expected according to NGS results, which also underline the need for more potent drugs against ALK in the high-risk setting of neuroendocrine histology.

Of these, 52 received first-line alectinib treatment (1L) and 56 received alectinib after crizotinib resistance (2L). Also, NF2-mutant patients only had a median PFS of 4 months, significantly poorer than those without (HR 11.1, 95CI 2.17-50; p<0.001). Conclusions By analyzing different mutational profiles of ALK-rearranged patients after alectinib treatment, we proposed MET and NF2 as putative mechanisms that conferred resistance to early resistance of first-line alectinib, which shone light on future tailored treatment for ALK-positive NSCLCs.

Another pt with the G1202R mutation following alectinib treatment had tumor shrinkage of 27.9%. APG-2449 has a favorable safety and PK profile and was well tolerated in 84 subjects. Preliminary efficacy was observed in pts whose disease was resistant to second-generation TKIs, especially among those with brain metastases, and in TKI-naïve pts. Biomarker data indicated potential target engagement on FAK and immunomodulatory effects of APG-2449.

She was treated with alectinib and acquired ALK p.I1171N and p.V1180L mutations...After sequential lines of ceritinib and chemotherapy, lorlatinib was chosen as the fourth-line therapy and maintained control for 6 months...To the best of our knowledge, this case is the first to provide clinical evidence of antitumor activity of olaparib plus ALK TKI in ALK-positive, gBRCA-mutated metastatic NSCLC. Together with previous reports in EGFR-positive or driver-negative patients, our finding warrants further studies on PARP inhibition in BRCA1/2-mutated NSCLC.

ALK rearrangements are detected in approximately 4% of patients with advanced non-small cell lung cancer (NSCLC), and the tyrosine kinase inhibitors (TKIs) crizotinib, alectinib, brigatinib, ceritinib, and lorlatinib have been approved by the FDA for the treatment of ALK-positive NSCLC. The dPCR method was highly sensitive in detecting gene mutations with low allele frequency. It was also found to be able to monitor variable resistance mutations over time during ALK-TKI treatment. In addition, we found that the appearance of G1202R did not always indicate clinical acquisition of resistance that required drug modification.

Brigatinib showed clinically meaningful efficacy in Japanese patients with ALK+ NSCLC refractory to alectinib (with or without prior crizotinib).

Brigatinib showed clinically meaningful efficacy in Japanese patients refractory to prior alectinib (first line or post crizotinib), regardless of prior chemotherapy. The safety profile of brigatinib was consistent with prior studies and no new safety findings were identified. Research Funding: Takeda Pharmaceutical Company Ltd