Overall Survival, Treatment Duration, and Rechallenge Outcomes With ICI Therapy for Recurrent or Metastatic HNSCC.

Importance: Immune checkpoint inhibition (ICI) is a frontline treatment for recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), but questions remain surrounding optimal duration of therapy, benefits and risks of ICI rechallenge, and efficacy in first vs subsequent lines of therapy. Objectives: To estimate survival in US patients receiving ICI-based treatment for R/M HNSCC, compare outcomes associated with treatment discontinuation vs continuation at 1 or 2 years, and assess outcomes after immunotherapy rechallenge. Design, Setting, and Participants: This retrospective, population-based cohort study included adult patients in the Flatiron Health nationwide oncology database treated with immunotherapy for R/M HNSCC from 2015 to 2023. Data cutoff was August 31, 2023; data analysis was conducted from December 2023 to February 2024. Exposures: Treatment continuation vs discontinuation at 1 and 2 years; rechallenge with ICI after at least a 60-day period off ICI therapy without intervening systemic treatment (immediate rechallenge), or with intervening systemic treatment (delayed rechallenge). Main Outcomes and Measures: Overall survival (OS) from ICI initiation was analyzed using the Kaplan-Meier method. Cox multivariable regression was used to examine associations of key variables (line of therapy, human papillomavirus [HPV] status, Eastern Cooperative Oncology Group [ECOG] performance status) with survival. Results: The cohort included 4549 patients with R/M HNSCC who received ICI-containing therapy (median [IQR] age, 66 [59-72] years; 3551 [78.1%] male; 56 [1.2%] Asian, 260 [5.7%] Black or African American, 3020 [66.4%] White, 1213 [26.7%] other or unknown race; 3226 [70.9%] ECOG performance status 0 or 1). There were 3000 patients (65.9%) who received ICI in frontline and 1207 (26.5%) in second line; 3478 patients (76.5%) received ICI monotherapy. Median (IQR) OS was 10.9 (4.1-29.1) months and was longer in patients who received ICI in frontline therapy (12.2 [4.8-32.0] vs 8.7 [3.2-22.4] months), had HPV-positive cancer (16.6 [6.5-43.9] vs 8.8 [3.5-24.0] months), and had ECOG performance status 0 or 1 (13.5 [5.2-33.9] vs 5.5 [2.0-13.7] months). There were no survival differences on adjusted analysis between patients who stopped vs those who continued ICI at 1 or 2 years. Median (IQR) OS after ICI rechallenge was 15.7 (13.7-21.9) months in the immediate rechallenge group and 9.9 (3.7-18.1) months in the delayed rechallenge group. Conclusions and Relevance: In this large cohort study of patients with R/M HNSCC receiving ICI-based therapy, survival estimates closely mirrored clinical trial results, both in frontline and later-line settings. Discontinuation of ICI in long-term responders at 1 or 2 years may be a reasonable strategy that does not appear to compromise survival. ICI rechallenge was associated with clinical benefit in a subset of patients.

Plunging Into the PACIFIC: Outcomes of Patients With Unresectable KRAS-Mutated Non-Small Cell Lung Cancer Following Definitive Chemoradiation and Durvalumab Consolidation.

BACKGROUND: Immune checkpoint inhibitor (ICI) consolidation following concurrent chemoradiotherapy (CRT) substantially improved progression free survival (PFS) and overall survival (OS) in the PACIFIC trial becoming the standard of care in locally-advanced, unresectable NSCLC. KRAS mutation may influence response to ICI. METHODS: In this single-institution, retrospective analysis, we compared treatment outcomes for patients with unresectable KRAS mutated (KRAS-mt) and wild-type (KRAS-wt) NSCLC treated with CRT between October 2017 and December 2021. Kaplan-Meier analysis was conducted comparing median progression free survival and median overall survival from completion of radiotherapy in all KRAS-mt patients and KRAS-G12C-mutated patients. Outcomes were also compared with and without ICI consolidation. RESULTS: Of 156 patients, 42 (26.9%) were KRAS-mt and 114 (73.1%) were KRAS-wt. Baseline characteristics differed only in histology; KRAS-mt NSCLC more likely to be adenocarcinoma. KRAS-mt patients had worse PFS (median 6.3 vs. 10.7 months, P = .041) but similar OS (median 23.1 vs. 27.3 months, P = .237). KRAS-mt patients were more likely to not receive ICI due to rapid disease progression post-CRT (23.8% vs. 4.4%, P = .007). Among patients who received ICI (n = 114), KRAS-mt was not associated with inferior PFS (8.1 vs. 11.9 months, P = .355) or OS (30.5 vs. 31.7 months, P = .692). KRAS-G12C patients (n = 22) had similar PFS and OS to other KRAS-mt. CONCLUSION: In one of the largest post-CRT KRAS-mt cohort published, KRAS-mt was associated with inferior PFS, largely due to rapid progression prior to ICI consolidation, but did not affect OS. Among those who received ICI consolidation, outcomes were comparable regardless of KRAS-mt status.

Utilization and Factors Precluding Receipt of Checkpoint Inhibitor Consolidation for Stage III NSCLC in a Large US Academic Health System.

OBJECTIVES: We sought to determine the proportion of patients with stage III non-small cell lung cancer (NSCLC) who initiate consolidation durvalumab or other immune checkpoint inhibitors (ICIs) after concurrent chemoradiotherapy (cCRT), as well as reasons for nonreceipt and prognostic implications. MATERIALS AND METHODS: We retrospectively identified consecutive patients with unresectable stage III NSCLC treated with definitive cCRT between October 2017 and December 2021 within a large US academic health system. Patients either received consolidation ICIs (ICI group) or did not (no-ICI group). Baseline characteristics and overall survival (OS) of the groups were assessed. Factors predictive of ICI nonreceipt were evaluated using logistic regression. RESULTS: Of 333 patients who completed cCRT, 229 (69%) initiated consolidation ICIs; 104 (31%) did not. Reasons for ICI nonreceipt included progressive disease post-cCRT (N = 31, 9%), comorbidity or intercurrent illness (N = 25, 8%), cCRT toxicity (N = 23, 7%; 19/23 pneumonitis), and EGFR/ALK alteration (N = 14, 4%). The no-ICI group had worse performance status and a higher rate of baseline pulmonary comorbidity. Larger planning target volume was associated with post-cCRT progressive disease, and higher lung radiation dose with cCRT toxicity. Median OS was 16 months in the no-ICI group and 34.4 months in the ICI group. In the no-ICI group, OS was superior among those with EGFR/ALK alterations (median 44.5 months) and worst among those with progressive disease (median 5.9 months, P < 0.001). CONCLUSION: 31% of patients who completed cCRT for stage III NSCLC did not receive consolidation ICIs. Survival amongst these patients is poor, especially for those with progressive disease post-cCRT.

Outcomes Among Patients With Mucosal Head and Neck Squamous Cell Carcinoma Treated With Checkpoint Inhibitors.

Importance: Immune checkpoint inhibitors (CPIs) are now part of standard therapy for patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) because of improved outcomes compared with chemotherapy in clinical trials. However, data on outcomes in patients with HNSCC in the general population who are treated with CPIs remain limited. Objective: To assess response rates, survival outcomes, and associations with key clinical covariates in a large, contemporary cohort of patients with recurrent or metastatic mucosal HNSCC who were treated with CPIs with or without chemotherapy. Design, Setting, and Participants: This retrospective cohort study included patients older than 18 years who received CPI-based therapy for recurrent or metastatic HNSCC at the University of Pennsylvania from January 1, 2015, through August 15, 2021. Clinical and survival data were abstracted through medical record review. Exposures: Treatment with CPIs with or without chemotherapy for a diagnosis of HNSCC. Main Outcomes and Measures: The main outcomes were overall survival, progression-free survival, and response rates. Overall survival and progression-free survival were estimated by Kaplan-Meier methods. Multivariable Cox proportional hazards regression was used to examine associations of key clinical variables with survival; a χ2 test and logistic regression were used to assess associations with response rate. Results: The study cohort consisted of 212 patients, of whom 165 (77.8%) were male, 148 (69.8%) were former or current smokers, and 66 (31.1%) had an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or greater; median age was 63.2 years (IQR, 57.2-71.2 years). Primary tumor sites included the oropharynx (99 [46.7%]), oral cavity (61 [28.8%]), and larynx or hypopharynx (52 [24.5%]). Most (126 [59.4%]) received CPI as first-line systemic therapy, and 23 (10.8%) received combination CPI with chemotherapy. The overall response rate was 30.1%. Estimated 1-year overall survival was 51.8% (95% CI, 44.5%-58.8%), and estimated 1-year progression-free survival was 9.4% (95% CI, 5.0%-15.5%). Median overall survival was 12.9 months (IQR, 4.1-36.5 months), and median progression-free survival was 3.9 months (IQR, 1.9-17.8 months). Non-oral cavity primary site (vs oral cavity) was associated with improved overall survival (human papillomavirus-positive oropharynx: hazard ratio [HR], 0.567 [95% CI, 0.335-0.960]; all other sites: HR, 0.491 [95% CI, 0.298-0.810]), and T category of 4 at presentation (HR, 1.594; 95% CI, 1.062-2.394) and an ECOG performance status greater than 1 (HR, 2.720; 95% CI, 1.866-3.964) were associated with worse overall survival. Conclusions and Relevance: In this cohort study of patients with recurrent or metastatic HNSCC who received CPI therapy, the overall response rate was 30.1%. Patients with oral cavity cancer had worse overall survival compared with patients with HNSCC of other subsites. These findings support the use of CPI therapies for first- or second-line treatment of recurrent or metastatic HNSCC.