Clinical activity of brigatinib in ROS1-rearranged non-small cell lung cancer

BACKGROUND

Brigatinib is a potent ROS1 inhibitor. The existing data on its clinical activity in ROS1-rearranged non-small cell lung cancer (NSCLC) are limited to four cases.

METHODS

Six patients with ROS1-rearranged advanced NSCLC treated with brigatinib were identified through search of the internal databases of four participating cancer centers. Four additional patients were selected by PubMed and Google Scholar search. The objective response rate (ORR), progression-free survival (PFS) (RECIST v.1.1), duration of treatment (DOT), and safety were assessed.

RESULTS

Of eight patients evaluable for response assessment (crizotinib naive-1, crizotinib resistant -7), three patients demonstrated a partial response (ORR-37%). One crizotinib-naive patient had an ongoing response at 21.6 months. Of seven crizotinib-resistant patients, two patients demonstrated a partial response (ORR-29%), and one patient (14%) had stable disease. PFS, available in four crizotinib-resistant patients, was 7.6 + , 2.9, 2.0, and 0.4 months. In crizotinib-resistant patients, DOT was 9.7 + , 7.7 + , 7.6 + , 4.0, 2.0, 1.1, 0.4 months, and was not reported in two patients. Genomic profiling in one responder revealed no ROS1 alteration, suggesting that the response was attributable to "off-target" brigatinib activity. In two patients with progressive disease, genomic profiling demonstrated a cMET exon 14 mutation + KRAS G12A mutation in one case, and a persisting ROS1-CD74 fusion + TP53 K139N, FGFR2 E250G, ATM G2695D, and NF1 R2258Q mutations in the other. No grade 3-5 toxicity was observed.

CONCLUSION

Brigatinib demonstrated modest activity in crizotinib-resistant ROS1-rearranged NSCLC. Its intracranial and systemic activity should be assessed in correlation with the underlying molecular mechanism of crizotinib resistance.

Immune checkpoint inhibitors for patients with advanced lung cancer and oncogenic driver alterations: results from the IMMUNOTARGET registry

Background

Anti-PD1/PD-L1 directed immune checkpoint inhibitors (ICI) are widely used to treat patients with advanced non-small-cell lung cancer (NSCLC). The activity of ICI across NSCLC harboring oncogenic alterations is poorly characterized. The aim of our study was to address the efficacy of ICI in the context of oncogenic addiction.

Patients and methods

We conducted a retrospective study for patients receiving ICI monotherapy for advanced NSCLC with at least one oncogenic driver alteration. Anonymized data were evaluated for clinicopathologic characteristics and outcomes for ICI therapy: best response (RECIST 1.1), progression-free survival (PFS), and overall survival (OS) from ICI initiation. The primary end point was PFS under ICI. Secondary end points were best response (RECIST 1.1) and OS from ICI initiation.

Results

We studied 551 patients treated in 24 centers from 10 countries. The molecular alterations involved KRAS (n = 271), EGFR (n = 125), BRAF (n = 43), MET (n = 36), HER2 (n = 29), ALK (n = 23), RET (n = 16), ROS1 (n = 7), and multiple drivers (n = 1). Median age was 60 years, gender ratio was 1 : 1, never/former/current smokers were 28%/51%/21%, respectively, and the majority of tumors were adenocarcinoma. The objective response rate by driver alteration was: KRAS = 26%, BRAF = 24%, ROS1 = 17%, MET = 16%, EGFR = 12%, HER2 = 7%, RET = 6%, and ALK = 0%. In the entire cohort, median PFS was 2.8 months, OS 13.3 months, and the best response rate 19%. In a subgroup analysis, median PFS (in months) was 2.1 for EGFR, 3.2 for KRAS, 2.5 for ALK, 3.1 for BRAF, 2.5 for HER2, 2.1 for RET, and 3.4 for MET. In certain subgroups, PFS was positively associated with PD-L1 expression (KRAS, EGFR) and with smoking status (BRAF, HER2).

Conclusions

: ICI induced regression in some tumors with actionable driver alterations, but clinical activity was lower compared with the KRAS group and the lack of response in the ALK group was notable. Patients with actionable tumor alterations should receive targeted therapies and chemotherapy before considering immunotherapy as a single agent.

Patient-derived xenografts effectively capture responses to oncology therapy in a heterogeneous cohort of patients with solid tumors

Background

While patient-derived xenografts (PDXs) offer a powerful modality for translational cancer research, a precise evaluation of how accurately patient responses correlate with matching PDXs in a large, heterogeneous population is needed for assessing the utility of this platform for preclinical drug-testing and personalized patient cancer treatment.

Patients and methods

Tumors obtained from surgical or biopsy procedures from 237 cancer patients with a variety of solid tumors were implanted into immunodeficient mice and whole-exome sequencing was carried out. For 92 patients, responses to anticancer therapies were compared with that of their corresponding PDX models.

Results

We compared whole-exome sequencing of 237 PDX models with equivalent information in The Cancer Genome Atlas database, demonstrating that tumorgrafts faithfully conserve genetic patterns of the primary tumors. We next screened PDXs established for 92 patients with various solid cancers against the same 129 treatments that were administered clinically and correlated patient outcomes with the responses in corresponding models. Our analysis demonstrates that PDXs accurately replicate patients' clinical outcomes, even as patients undergo several additional cycles of therapy over time, indicating the capacity of these models to correctly guide an oncologist to treatments that are most likely to be of clinical benefit.

Conclusions

Integration of PDX models as a preclinical platform for assessment of drug efficacy may allow a higher success-rate in critical end points of clinical benefit.