KRAS G12C Mutant Non-Small Cell Lung Cancer Linked to Female Sex and High Risk of CNS Metastasis: Population-based Demographics and Survival Data From the National Swedish Lung Cancer Registry

BACKGROUND

Real-world data on demographics related to KRAS mutation subtypes are crucial as targeted drugs against the p.G12C variant have been approved.

METHOD

We identified 6183 NSCLC patients with reported NGS-based KRAS status in the Swedish national lung cancer registry between 2016 and 2019. Following exclusion of other targetable drivers, three cohorts were studied: KRAS-G12C (n = 848), KRAS-other (n = 1161), and driver negative KRAS-wild-type (wt) (n = 3349).

RESULTS

The prevalence of KRAS mutations and the p.G12C variant respectively was 38%/16% in adenocarcinoma, 28%/13% in NSCLC-NOS and 6%/2% in squamous cell carcinoma. Women were enriched in the KRAS-G12C (65%) and KRAS-other (59%) cohorts versus KRAS-wt (48%). A high proportion of KRAS-G12C patients in stage IV (28%) presented with CNS metastasis (vs. KRAS-other [19%] and KRAS-wt [18%]). No difference in survival between the mutation cohorts was seen in stage I-IIIA. In stage IV, median overall survival (mOS) from date of diagnosis was shorter for KRAS-G12C and KRAS-other (5.8 months/5.2 months) vs. KRAS wt (6.4 months). Women had better outcome in the stage IV cohorts, except in KRAS-G12C subgroup where mOS was similar between men and women. Notably, CNS metastasis did not impact survival in stage IV KRAS-G12C, but was associated with poorer survival, as expected, in KRAS-other and KRAS-wt.

CONCLUSION

The KRAS p.G12C variant is a prevalent targetable driver in Sweden and significantly associated with female sex and presence of CNS metastasis. We show novel survival effects linked to KRAS p.G12C mutations in these subgroups with implications for clinical practice.

Real-world treatment and prognostic factors for survival in ALK+ non-small cell lung cancer (NSCLC) patients with brain metastases in China

BACKGROUND

To explore the efficacy and prognostic factors of different treatment modalities on anaplastic lymphoma kinase (ALK)+ non-small cell lung cancer (NSCLC) patients with brain metastases (BMs).

METHODS

A total of 86 patients were enrolled into the study. They were divided into two cohorts based on their history of treatment with ALK tyrosine kinase inhibitors (ALK-TKIs) prior to the incidence of BMs. ALK-TKI-naïve patients with BMs were included in cohort 1 (n = 59); patients who developed BMs after ALK-TKIs treatment were enrolled in cohort 2 (n = 27). Prognostic factors related with overall survival (OS) when treated with ALK-TKIs were assessed in multivariable analysis.

RESULTS

With a median follow-up of 41.8 months, the median OS was 34.8 months. In cohort 1, the OS, intracranial progression-free survival (iPFS), and progression-free survival (PFS) were 38.7 months (95% CI: 23.3 to 54.1), 18.5 months (95% CI: 9.6 to 27.4), and 19.1 months (95% CI: 13.7 to 24.5), respectively. Significantly improved OS and iPFS were noted in those patients in which second-generation ALK-TKIs versus crizotinib were initiated (OS: not reached vs. 29.0 months, p = 0.040; iPFS: 22.8 vs. 11.9 months, p = 0.035). In cohort 2, patients who experienced BMs as a result of the treatment failure of ALK-TKIs had a median OS of 27.1 months. Considerable duration of stable disease in patients with measurable BMs was observed (iPFS: 11.5 months, 95% CI: 4.4 to 18.6; PFS: 12.2 months, 95% CI: 3.2 to 21.1).

CONCLUSION

Second-generation ALK-TKIs further improved the duration of intracranial response and survival in ALK+ NSCLC patients with BMs in a real-world setting. The potent intracranial efficacy of second-generation ALK-TKIs might generate the lowered urgency of local treatment.

Phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost for metastatic cancer

BACKGROUND

Advanced radiotherapeutic treatment techniques limit the cognitive morbidity associated with whole-brain radiotherapy (WBRT) for brain metastasis through avoidance of hippocampal structures. However, achieving durable intracranial control remains challenging.

METHODS

We conducted a single-institution single-arm phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost (HSIB-WBRT) to metastatic deposits in adult patients with brain metastasis. Radiation therapy consisted of intensity-modulated radiation therapy delivering 20 Gy in 10 fractions over 2-2.5 weeks to the whole brain with a simultaneous integrated boost of 40 Gy in 10 fractions to metastatic lesions. Hippocampal regions were limited to 16 Gy. Cognitive performance and cancer outcomes were evaluated.

RESULTS

A total of 50 patients, median age 60 years (interquartile range, 54-65), were enrolled. Median progression-free survival was 2.9 months (95% CI: 1.5-4.0) and overall survival was 9 months. As expected, poor survival and end-of-life considerations resulted in a high exclusion rate from cognitive testing. Nevertheless, mean decline in Hopkins Verbal Learning Test-Revised delayed recall (HVLT-R DR) at 3 months after HSIB-WBRT was only 10.6% (95% CI: -36.5‒15.3%). Cumulative incidence of local and intracranial failure with death as a competing risk was 8.8% (95% CI: 2.7‒19.6%) and 21.3% (95% CI: 10.7‒34.2%) at 1 year, respectively. Three grade 3 toxicities consisting of nausea, vomiting, and necrosis or headache were observed in 3 patients. Scores on the Multidimensional Fatigue Inventory 20 remained stable for evaluable patients at 3 months.

CONCLUSIONS

HVLT-R DR after HSIB-WBRT was significantly improved compared with historical outcomes in patients treated with traditional WBRT, while achieving intracranial control similar to patients treated with WBRT plus stereotactic radiosurgery (SRS). This technique can be considered in select patients with multiple brain metastases who cannot otherwise receive SRS.

Efficacy of Crizotinib for Advanced ALK-Rearranged Non-Small-Cell Lung Cancer Patients with Brain Metastasis: A Multicenter, Retrospective Study in China

BACKGROUND

The efficacy of crizotinib for anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) patients with brain metastasis is controversial. Real-world research data are needed as further evidence.

OBJECTIVE

We conducted a multicenter, retrospective study to explore how crizotinib affects the control of brain metastasis and the survival outcomes among Chinese patients.

PATIENTS AND METHODS

We reviewed the medical records of unselected ALK-rearranged NSCLC patients treated with crizotinib at five hospitals in China from January 1, 2013 to November 30, 2017. Patients developing brain metastasis either before or during crizotinib treatment were included. Survival outcomes were analyzed by the Kaplan-Meier method, and prognostic factors were analyzed by multivariate Cox regression.

RESULTS

A total of 174 patients were included in the analysis; 95 of these patients had baseline brain metastasis, while 79 patients developed brain metastasis during crizotinib treatment. Among patients with baseline brain metastasis, the median intracranial time to progression was 19.3 months (95% confidence interval [CI] 12.5-26.2) and the median overall survival (OS) was 53.4 months (95% CI not reached). A total of 135 patients experienced intracranial progression, and 94 of these patients continued crizotinib beyond progressive disease (CBPD). There was no significant difference in the median OS between patients with CBPD and without CBPD (48.3 months vs 53.4 months; p = 0.296).

CONCLUSIONS

ALK-rearranged advanced NSCLC patients with baseline brain metastasis can still achieve OS benefits from crizotinib treatment. However, patients with intracranial progression may not obtain a long-term survival benefit from continuation of CBPD.

Exploratory Analysis of Brigatinib Activity in Patients With Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer and Brain Metastases in Two Clinical Trials

Purpose In patients with crizotinib-treated, anaplastic lymphoma kinase gene ( ALK)-rearranged non-small-cell lung cancer (ALK-positive NSCLC), initial disease progression often occurs in the CNS. We evaluated brigatinib, a next-generation ALK inhibitor, in patients with ALK-positive NSCLC with brain metastases. Patients and Methods Patients with ALK-positive NSCLC received brigatinib (90 to 240 mg total daily) in a phase I/II trial (phI/II; ClinicalTrials.gov identifier: NCT01449461) and in the subsequent randomized phase II trial ALTA (ALK in Lung Cancer Trial of AP26113; ClinicalTrials.gov identifier: NCT02094573; patients in arm A received 90 mg once daily; patients in arm B received 180 mg once daily with 7-day lead-in at 90 mg). Primary end points (systemic objective response rates [ORRs]) were previously reported. Independent review committees assessed intracranial efficacy in patients with baseline brain metastases. Results Most patients with ALK-positive NSCLC had baseline brain metastases (50 of 79 [63%], phI/II; 80 of 112 [71%] and 73 of 110 [66%] in ALTA arms A and B, respectively), many of whom had no prior brain radiotherapy (23 of 50 [46%], phI/II; 32 of 80 [40%], ALTA arm A; 30 of 73 [41%], arm B). All patients, except four in phI/II, had received crizotinib. Among patients with measurable (≥ 10 mm) brain metastases, confirmed intracranial ORR was 53% (eight of 15; 95% CI, 27% to 79%) in phI/II, 46% (12 of 26; 95% CI, 27% to 67%) in ALTA arm A, and 67% (12 of 18; 95% CI, 41% to 87%) in arm B. Intracranial ORRs were similar in subsets without prior radiation or progression postradiation. Among patients with any baseline brain metastases, median intracranial progression-free survival (iPFS) was 14.6 months (95% CI, 12.7 to 36.8 months), phI/II; 15.6 months (95% CI, 9.0 to 18.3 months), ALTA arm A; 18.4 months (95% CI, 12.8 months to not reached), ALTA arm B. Conclusion Brigatinib yielded substantial intracranial responses and durable iPFS in ALK-positive, crizotinib-treated NSCLC, with highest iPFS in patients receiving 180 mg once daily (with lead-in).

Alectinib for advanced ALK-positive non-small-cell lung cancer

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy, safety and tolerability, dosage and administration, and place in therapy of alectinib for treatment of patients with non-small-cell lung cancer (NSCLC) are reviewed.

SUMMARY

In patients with NSCLC driven by mutations of ALK, the gene coding for anaplastic lymphoma kinase (ALK), treatment with the ALK inhibitor crizotinib has been found to provide median progression-free survival (PFS) of 10.9 months; however, therapeutic failures and tumor progression to brain metastases are common with crizotinib use, prompting research to find more potent and tolerable ALK inhibitors that target major oncogenic drivers of NSCLC. Alectinib is a next-generation ALK inhibitor initially approved by the Food and Drug Administration for use in patients with metastatic ALK-positive NSCLC who are intolerant of or have disease progression during crizotinib therapy. In clinical trials, alectinib was found effective for delaying disease progression and, more importantly, reducing brain metastases in patients with NSCLC who developed resistance or intolerance to previous crizotinib therapy. Published data from clinical trials indicate that the most common grade 1 and 2 adverse effects associated with alectinib use are fatigue, constipation, peripheral edema, and myalgia; the most common grade 3 or 4 reactions include increases in creatine phosphokinase, alanine aminotransferase, and aspartate aminotransferase levels.

CONCLUSION

Alectinib appears to be effective and safe for use in patients with metastatic ALK-positive NSCLC, with demonstrated superiority over crizotinib in terms of PFS rates. Research to better define ALK inhibitor resistance mechanisms and alectinib's place in therapy is ongoing.