Hearing Outcomes in Cisplatin or Cetuximab Combined with Radiation for Patients with HPV-Associated Oropharyngeal Cancer in NRG/RTOG 1016

PURPOSE/OBJECTIVE(S)

NRG/RTOG 1016 was a noninferiority phase 3 trial comparing the efficacy of radiation with either cisplatin (RT+Cisp) or cetuximab (RT+Cetux) for patients with HPV+ oropharyngeal cancer (OPC). Perceived hearing handicap was included as a patient-reported outcome (PRO) secondary endpoint. The primary hypothesis was that perceived hearing handicap would be greater for patients receiving RT+Cisp compared to RT+Cetux.

MATERIALS/METHODS

Perceived hearing handicap was measured at baseline, end of treatment, 3, 6, and 12-months post-treatment using the Hearing Handicap Inventory for Adults Screening Version (HHIA-S), a 10-item self-assessment questionnaire designed to measure patients' reactions to their hearing loss. Total HHIA-S scores range from 0 to 40; higher total score indicates more severe perceived hearing handicap. Hearing handicap categories (none, mild/moderate, and severe) were also analyzed. Mixed ordinal logistic models were used to analyze the raw HHIA-S scores and handicap categories (2-sided alpha 0.05).

RESULTS

Participation in the PRO assessments was optional, with 368 patients participating in the hearing PRO. No significant differences in patient/tumor characteristics were found between PRO participants/non-participants. Pre-treatment (mean [SD]) HHIA-S scores were not different for RT+Cisp (3.23 [6.28]) and RT+Cetux (4.77 [8.14]) groups. Post-treatment HHIA-S scores increased for RT+Cisp, and remained stable at the later follow-up time points. RT+Cetux scores remained stable from baseline. Change score from pre- to post-treatment was higher for RT+Cisp (4.32, 95% CI = [2.57, 6.07]) than RT+Cetux (0.08, 95% CI = [-1.15, 1.31]; p < 0.001). For hearing handicap category, post-treatment RT+Cisp had a significantly higher percentage of mild/moderate and severe cases (32%) compared to RT+Cetux (20%). From pre- to post-treatment, worsening of hearing handicap category from normal to mild/moderate or severe was greater for RT+Cisp (24%) than for RT+Cetux (9%). The conditional odds of being in a higher self-perceived hearing handicap category in the RT+Cisp arm were 3.57 (95% CI [2.04, 6.25]) times that in the RT+Cetux arm. Averaging over patients, the marginal odds ratio was 2.46 (95% CI [1.65, 3.66]).

CONCLUSION

Patients receiving concurrent RT+Cisp for HPV-associated OPC have significantly higher odds of worsening self-perceived hearing handicap after treatment than with RT+Cetux. This was consistent across time through one-year post-treatment. These findings inform hearing-related outcomes for patients with HPV-associated OPC.

Effectiveness of Cisplatin in P16+ Oropharyngeal Cancer According to Relative Risk for Cancer Events: Ancillary Analysis of RTOG 1016

PURPOSE/OBJECTIVE(S)

To test the hypothesis that the effectiveness of cisplatin in p16+ oropharyngeal squamous cell carcinoma (OPSCC) increases with patients' relative risk for cancer events.

MATERIALS/METHODS

Ancillary analysis of 805 patients enrolled on RTOG 1016 accessed via Project DataSphere. Eligible patients had p16+ OPSCC, AJCC 7th T1-T2 N2a-N3 or T3-T4 N0-N3 M0, ECOG PS 0-1. Patients were randomized to RT with concurrent cisplatin vs. cetuximab. Relative risk for competing events was quantified using the Head and Neck Cancer Intergroup predictive classifier (omega score). Higher scores indicate higher relative risk for cancer events (LRF or distant metastasis) vs. competing mortality. We compared this to favorable, unfavorable/low, and unfavorable/intermediate risk groups using standard criteria: NRG HN005 eligible/low RTOG risk (Ang et al.), HN005 ineligible/low RTOG risk, and intermediate RTOG risk. Omega score cutoffs were selected to match numbers in standard risk strata. HRs for the effect of cisplatin vs. cetuximab on PFS and OS were compared for standard vs. relative risk strata. 1-tailed interaction tests were used to test whether cisplatin effectiveness increased within risk strata.

RESULTS

There were 354, 219, and 232 patients in standard favorable, unfavorable/low, and unfavorable/intermediate risk groups. Omega score cutoffs were 0.80 and 0.84 to define low, intermediate, and high relative risk groups. Discordant standard vs. relative risk classifications occurred in 559 patients (69.4%). Increasing omega score was associated with significantly higher relative HR (rHR) for cancer events (3.40, 95% CI: 1.66-6.96) and increasing effectiveness of cisplatin vs. cetuximab (Table), but standard risk grouping was not (rHR 0.80, 95% CI: 0.49-1.32). The effect of cisplatin on PFS significantly increased with higher omega score (interaction -0.30, p = .046), but decreased with increasing standard risk strata (interaction +0.27, p = NS).

CONCLUSION

The effectiveness of cisplatin in p16+ OPSCC increased with higher omega score but not with standard risk group. Relative risk for cancer events should be taken into account when designing deintensification strategies.

HPV Circulating Cell-Free DNA Kinetics in Cervical Cancer Patients Undergoing Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

The human papilloma virus (HPV) is a significant cause of cervical cancer and viral DNA can be detected in the blood of patients with cervical cancer (cfHPV-DNA). We hypothesized that detecting HPV cfDNA before, during and after chemoradiation (CRT) could provide insights into disease extent, clinical staging, and treatment response.

MATERIALS/METHODS

Forty-seven patients with cervical cancer were enrolled on this study between 2017 and 2022, either as part of a standard-of-care (SOC) treatment banking protocol (33 patients) or as part of a clinical trial combining a therapeutic HPV vaccine (PDS0101; Immunocerv, 14 patients). Longitudinal plasma samples were collected from each patient as baseline, during week 1, 3 or 5 of CRT. cfHPV-DNA was quantified using droplet digital PCR targeting the HPV E6/E7 oncogenes of 13 high-risk types based on analysis of cervical tumor genotype (AmpFire). Clinical covariates, including FIGO stage, primary tumor size, and treatment response were studied using appropriate statistical tests.

RESULTS

All 47 patients had detectable HPV cfDNA during CRT with 38 out of 47 having HPV type 16 detected. The median cfDNA at baseline was 24.5 copies/mL, with a range of 0 to 157,638 copies/mL. Of the 35 patients with at least three measurements, 20 (57%) had peak cfDNA counts at week 3, and 30 out of 35 showed a decline in cfDNA counts at week 5 compared to week 3. The proportion of patients who cleared cfDNA (<16 copies/mL) increased with each week of CRT, reaching 75% at week 5. Baseline cfDNA counts were associated with para-aortic nodal involvement (p<0.0001) but not with FIGO stage or gross tumor volume. A greater proportion of patients treated with therapeutic HPV-directed vaccine had clearance of cfDNA counts as compared to those treated with SOC (at week 3, 38% vs 5%, P = 0.02 and week 5, 79% vs 22%, P = 0.0054) CONCLUSION: HPV cfDNA levels change dynamically throughout definitive CRT and peak during the first 3 weeks for the majority of patients. Treatment with a therapeutic HPV vaccine was associated with a more rapid decline in cfHPV DNA. Further analysis of cfDNA kinetics could provide valuable information on the relationship between cfDNA levels, treatment response, and clinical outcomes.

The KRAS-Variant and Cetuximab in HPV-Positive Oropharyngeal Cancer in NRG/RTOG 1016

PURPOSE/OBJECTIVE(S)

NRG/RTOG 1016 was a non-inferiority phase III trial comparing radiation with cisplatin versus cetuximab monotherapy for patients with HPV-positive oropharyngeal squamous cell carcinoma (SCC). The trial did not meet the non-inferiority criteria for overall survival (OS) and had significantly worse progression-free survival (PFS) and locoregional failure (LRF) in patients treated with cetuximab. Based on prior evidence that HNSCC patients with a germ-line mutation in KRAS (the KRAS-variant) had a positive response to radiation with cisplatin plus cetuximab without increased toxicity, samples from RTOG 1016 were used to test the protocol-specified hypothesis that KRAS-variant patients will have better outcomes when receiving IMRT + cetuximab monotherapy compared to IMRT + cisplatin.

MATERIALS/METHODS

The KRAS-variant was tested in 562 samples at MiraDx, a CLIA-certified laboratory. OS, PFS, LRF, and distant metastases (DM) were as defined per the RTOG 1016 protocol, and hazard ratios (HRs) were estimated by (cause-specific) Cox models. Negative binomial regression was used to model the number of treatment-related acute and late (≤ and > 180 days from end of treatment, respectively) grade 3-5 adverse events. To assess the predictive role of the KRAS-variant, all models included KRAS, assigned treatment, and their interaction, with the interaction tested at two-sided 0.05. HRs and toxicity ratios are expressed as IMRT + cetuximab / IMRT + cisplatin.

RESULTS

The prevalence of the KRAS-variant was 16% with similar patient and tumor characteristics and well-balanced treatment arms for variant and non-variant patients. Median follow-up was 8.6 years. There was no significant interaction between KRAS and treatment for OS (p = 0.99), PFS (p = 0.56), LRF (p = 0.09), or DM (p = 0.19) (Table 1). In KRAS-variant patients the mean acute and late toxicity ratios were 0.53 (95% CI 0.36, 0.80) and 1.62 (95% CI 0.57, 4.62). In non-variant patients, the mean acute and late toxicity ratios were 0.80 (95% CI 0.67, 0.95) and 0.55 (95% CI 0.35, 0.87), respectively. The interaction of KRAS and treatment was not significant for acute (p = 0.07) or late toxicity (p = 0.07).

CONCLUSION

While this study does not directly refute prior evidence that KRAS-variant patients benefit from radiation + cisplatin and cetuximab, this study does not support the hypothesis that the KRAS-variant is a predictive biomarker of improved outcome in HPV+ oropharyngeal SCC patients treated with IMRT + cetuximab alone, and suggests that for KRAS-variant patients, potential benefits in LRF and acute toxicity with cetuximab may be offset by worse DM and worse late toxicity.

Durvalumab with or without tremelimumab versus the EXTREME regimen as first-line treatment for recurrent or metastatic squamous cell carcinoma of the head and neck: KESTREL, a randomized, open-label, phase III study

BACKGROUND

Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) have a poor prognosis. The phase III KESTREL study evaluated the efficacy of durvalumab [programmed death-ligand 1 (PD-L1) antibody] with or without tremelimumab [cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody], versus the EXTREME regimen in patients with R/M HNSCC.

PATIENTS AND METHODS

Patients with HNSCC who had not received prior systemic treatment for R/M disease were randomized (2 : 1 : 1) to receive durvalumab 1500 mg every 4 weeks (Q4W) plus tremelimumab 75 mg Q4W (up to four doses), durvalumab monotherapy 1500 mg Q4W, or the EXTREME regimen (platinum, 5-fluorouracil, and cetuximab) until disease progression. Durvalumab efficacy, with or without tremelimumab, versus the EXTREME regimen in patients with PD-L1-high tumors and in all randomized patients was assessed. Safety was also assessed.

RESULTS

Durvalumab and durvalumab plus tremelimumab were not superior to EXTREME for overall survival (OS) in patients with PD-L1-high expression [median, 10.9 and 11.2 versus 10.9 months, respectively; hazard ratio (HR) = 0.96; 95% confidence interval (CI) 0.69-1.32; P = 0.787 and HR = 1.05; 95% CI 0.80-1.39, respectively]. Durvalumab and durvalumab plus tremelimumab prolonged duration of response versus EXTREME (49.3% and 48.1% versus 9.8% of patients remaining in response at 12 months), correlating with long-term OS for responding patients; however, median progression-free survival was longer with EXTREME (2.8 and 2.8 versus 5.4 months). Exploratory analyses suggested that subsequent immunotherapy use by 24.3% of patients in the EXTREME regimen arm contributed to the similar OS outcomes between arms. Grade 3/4 treatment-related adverse events (TRAEs) for durvalumab, durvalumab plus tremelimumab, and EXTREME were 8.9%, 19.1%, and 53.1%, respectively.

CONCLUSIONS

In patients with PD-L1-high expression, OS was comparable between durvalumab and the EXTREME regimen. Durvalumab alone, and with tremelimumab, demonstrated durable responses and reduced TRAEs versus the EXTREME regimen in R/M HNSCC.

Prognostic significance of human papillomavirus (HPV) tumor status for patients with head and neck squamous cell carcinoma (HNSCC) in a prospective, multi-center phase II clinical trial

6000

Background: Retrospective, single-institution studies suggest that patients with HPV- positive (HPV+) HNSCC may have a better prognosis than patients with HPV-negative (HPV-) tumors. Methods: The effect of tumor HPV status on treatment response and survival outcomes was prospectively evaluated in a multi-center, phase II clinical trial conducted by the Eastern Cooperative Oncology Group. Patients with newly diagnosed, resectable, stage III or IV HNSCC of the oropharynx or larynx were uniformly treated with two cycles of induction chemotherapy (IC; paclitaxel 175 mg/m2 and carboplatin AUC 6) followed by chemoradiation (CRT; weekly paclitaxel 30 mg/m2 administered concurrently with standard fractionation external beam radiation therapy, total dose of 70 Gy in 35 fractions over 7 weeks). Tumor HPV status was determined by in situ hybridization on formalin-fixed, paraffin-embedded tumors. The independent effect of tumor HPV status on survival was evaluated by Cox-proportional hazards models. Results: Genomic DNA of oncogenic HPV type 16, 33, or 35 was specifically located within tumor cell nuclei of 40% (95%CI 29.7- 50.1) of evaluable cases. Factors associated with HPV+ tumor in univariate analysis included Caucasian race (p=0.02), improved ECOG performance status (p=0.01), an oropharyngeal primary (p<0.001), early tumor stage (p=0.02), and basaloid histology (P<0.001). Response rates assessed after IC (81.6% vs. 55.2%, p=0.01) and CRT (84.2% vs. 56.9%, p=0.07) were higher in patients with HPV+ than HPV- tumors. After a median follow-up time of 39.1 months, patients with HPV+ tumors had a risk of progression that was 72% lower (HR=0.28, 95% CI: 0.07–1.0) and a risk of death that was 79% lower (HR=0.21, 95% CI: 0.06–0.74) than patients with HPV- tumors, after adjustment. Conclusion: The improved prognosis of HPV+ HNSCC has been confirmed in a prospective clinical trial and may be explained in part by enhanced sensitivity to chemotherapy and radiation.

No significant financial relationships to disclose.

Incidence trends for human papillomavirus-related (HPV-R) and unrelated (HPV-U) head and neck squamous cell carcinomas (HNSCC) in the United States (US)

6001

Background: HNSCC are etiologically heterogeneous, with one subset primarily attributable to HPV and another to tobacco and alcohol. Methods: Data from SEER9 program registries were used to investigate the potential influence of HPV on incidence and survival of HNSCC in the US from 1973–2003. HNSCCs (N=58,158) were classified by anatomic site as potentially HPV-R (base of tongue; tonsil; oropharynx; N=16,712) or HPV-U (lip; tongue; gum; floor of mouth; palate; other mouth; hypopharynx; ill-defined sites of lip, oral cavity, and pharynx; N=41,446). Joinpoint regression was used to assess incidence trends and life-table methods were used to compare survival for HPV-R and HPV-U HNSCCs. Results: For HPV-R HNSCCs, age-adjusted incidence increased significantly from 1973–2003 (annual percent change [APC] = 0.65), particularly among males (APC=1.02), whites (APC=0.89), and younger ages (APCs for 30–39 = 1.46; 40- 49=1.92; 50–59=0.61, and =60= -0.66). By contrast, HPV-U HNSCC incidence was stable from 1973–1983 and then decreased significantly from 1983–2003 (APC= -2.42). Mean age at diagnosis was younger for HPV-R HNSCC than HPV-U (61.1 vs. 64.5 years; p<0.001), and from 1973- 2003, decreased significantly for HPV-R, but increased for HPV-U. Improvements in overall survival (OS) were observed for HPV-R (all stages) and HPV-U (regional and distant) HNSCC treated by radiotherapy (RT) from 1973–2003, but were more marked for HPV-R HNSCC, e.g. absolute increase in two-year OS for regional disease of 24.4% (vs. 5.8% for HPV-U). OS for HPV-R (local and regional) was significantly better than HPV-U HNSCC if treated by RT, but worse if not so treated. Conclusions: The proportion of HNSCC that is potentially HPV- R increased in the US from 1973–2003, particularly among recent birth cohorts, perhaps due to changing sexual and smoking behaviors. Recent improvements in locoregional control with RT-based therapy may be due in part to a gradual shift in the etiology of the underlying disease.

No significant financial relationships to disclose.