Efficacy of sonic hedgehog inhibitors rechallenge, after initial complete response in recurrent advanced basal cell carcinoma: a retrospective study from the CARADERM database

Evaluation of the Tolerability of Hedgehog Pathway Inhibitors in the Treatment of Advanced Basal Cell Carcinoma: A Narrative Review of Treatment Strategies

Hedgehog pathway inhibitors (HHIs) have broadened the treatment options available for patients with advanced basal cell carcinoma (BCC) for whom traditional therapeutic approaches are not feasible or effective. Sonidegib and vismodegib are oral HHIs that were approved for treatment of patients with advanced BCC after demonstrating promising efficacy in the pivotal Phase II BOLT (NCT01327053) and ERIVANCE (NCT00833417) trials, respectively. However, the incidence and types of treatment-emergent adverse events (AEs) observed with these agents may limit continuous use of HHIs and ultimately impact clinical outcomes. In this review, we summarize the safety and tolerability profiles of sonidegib and vismodegib and discuss potential management strategies for HHI class-effect AEs, including muscle spasms, creatine phosphokinase increase, alopecia, and dysgeusia. These AEs primarily occur early in treatment and can lead to treatment discontinuation. Differences in the pharmacokinetic profiles of sonidegib and vismodegib may contribute to the variability noted in times to onset and resolution of these and other AEs. Evidence suggests that protocol modifications, such as treatment interruptions and dose reductions, are effective ways to manage AEs while maintaining disease control. Nonpharmacologic and pharmacologic interventions may also be considered as part of an AE management strategy. Overall, healthcare providers and patients with advanced BCC should be aware of the HHI class-effect AEs and plan effective management strategies to avoid treatment discontinuation and optimize therapeutic response.

Hedgehog Inhibitors Beyond Clinical Complete Response in Basal Cell Carcinoma: Should I Stop or Should I Go?

INTRODUCTION

In advanced basal cell carcinoma (BCC), the issue of whether Hedgehog inhibitors (HHIs) should be stopped or not after clinical complete response (cCR) achievement remains an unmet clinical need.

MATERIALS AND METHODS

We conducted a retrospective, multicenter study across 7 Italian dermato-oncology units including patients with BCC who continued vismodegib after cCR between 2012 and 2019. We assessed the relationship between the duration of vismodegib intake (days to cCR [DTCR], days to stop after cCR [DTS], total treatment days [TTD]), and disease-free survival (DFS). Reasons to stop vismodegib were (R1) toxicity and (R2) disease recurrence. The relationship between DTCR, DTS, TTD, and DFS in the whole population and in R1 subgroup was assessed by Pearson's correlation coefficient (P < .05) and Bayesian statistics (BF10).

RESULTS

Sixty-eight BCC patients with a median (m) age of 75.5 years (39-100) were included. Most patients were male (N = 43, 63%), without Gorlin syndrome (N = 56, 82%) and with head and neck area as primary site (N = 51, 75%). After cCR, out of 68 patients, 90% (N = 61/68) discontinued vismodegib: 82% (N = 50/61) due to toxicity (R1), and 18% (N = 11/61) due to recurrence (R2). Conversely, 10% (N = 7/68) continued vismodegib until last follow-up. In the whole population (N = 68), cCR was achieved with a mDTCR of 180.50 days. DFS showed a significant correlation with DTS (P < .01, BF10 = 39.2) and TTD (P < .01, BF10 = 35566), while it was not correlated to DTCR (BF10 < 0.1). The analysis of R1 subgroup (N = 50) confirmed these results. DFS correlated with DTS in all recurrent patients (N = 38, r = 0.44, P < .01) and in the recurrent patients who stopped vismodegib for toxicity (N = 26, r = 0.665, P < .01). DFS was longer when vismodegib was maintained for >2 months after cCR (mDFS > 2 months, N = 54 vs. ≤ 2 months, N = 14: 470 vs. 175 d, P < .01).

CONCLUSIONS

Our retrospective results suggest that HHIs should be continued after cCR to improve DFS in BCC.

Immunotherapy and Its Timing in Advanced Basal Cell Carcinoma Treatment

For patients with advanced basal cell carcinoma (BCC), including locally advanced or metastatic BCC not amenable to curative surgery or radiotherapy, hedgehog pathway inhibitors (HHI) vismodegib and sonidegib are approved as first-line systemic treatment. Results from clinical trials highlight that the overall discontinuation rate of HHI treatment varies from 88% to 92% with vismodegib and is approximately 92% with sonidegib, and half of patients will discontinue HHI after approximately 8 to 12 months. The main factors weighing in on the decision to discontinue HHI include efficacy (tumor response), adverse events and patient decision. In clinical practice, some of the patients that stop HHI may be re-evaluated if the tumor becomes amenable to surgery, or restart HHI at a later time, while others will need to switch to immunotherapy, depending on the reasons for HHI discontinuation. In this review, we revisit the therapeutic decisions considering a switch from HHI to immunotherapy with anti-PD-1 agent cemiplimab and we highlight the place of cemiplimab in the therapeutic ladder for patients with advanced BCC. We discuss the evidence on the efficacy and safety of anti-PD-1 agents as second-line systemic monotherapy, or in combination with other treatments, and the emergence of checkpoint immunotherapy as a neoadjuvant treatment.

Long-term strategies for management of advanced basal cell carcinoma with hedgehog inhibitors

Basal cell carcinoma (BCC), the most common type of skin cancer, is characterized by aberrant activation of the hedgehog molecular pathway. Systemic therapy is indicated when local approaches, such as surgery and radiation, are inappropriate. In this article, a group of clinical experts recommends the long-term management strategy for advanced BCC patients treated with systemic therapy. The hedgehog inhibitors sonidegib and vismodegib are first-line treatments for advanced BCC with a long-lasting response, but long-term treatment with hedgehog inhibitors is often challenged by tolerability issues. However, several strategies for adverse effect management are available, such as dose interruptions, on-label alternate-day dosing and supportive medications. In conclusion, although BCC shows a high tumor mutational burden that favors a response to immunotherapy, experts recommend keeping patients on hedgehog inhibitors limiting immunotherapy to those who developed resistance during hedgehog inhibitor therapy or in case of persisting toxicity despite long-term management of adverse events.

Prognostic and Predictive Biomarkers in Head and Neck Squamous Cell Carcinoma Treated with Radiotherapy-A Systematic Review

Background: Radiotherapy is a mainstay in head and neck squamous cell carcinoma (HNSCC) treatment but is mostly applied without stratification by molecular diagnostics. Development of reliable biomarkers may have the potential to improve radiotherapy (RT) efficacy and reduce toxicity. We conducted a systematic review to summarize the field of biomarkers in HNSCC treated by RT. Methods: Pubmed and EMBASE were searched independently by two researchers following pre-defined inclusion and exclusion criteria. Z curves were generated to investigate publication bias. OncoKB was used for identification of druggable targets. Results: 134 manuscripts remained for data extraction. 12% of tumors were AJCC/UICC stage I-II and 82% were stage III-IV. The most common biomarkers were proteins (39%), DNA (14%) and mRNA (9%). Limiting analysis to prospective data and statistically significant results, we found three potentially druggable targets: ERCC2, PTCH1 and EGFR. Regarding data quality, AJCC/UICC stage was missing in 32% of manuscripts. 73% of studies were retrospective and only 7% were based on prospective randomized trials. Z-curves indicated the presence of publication bias. Conclusion: An abundance of potential biomarkers in HNSCC is available but data quality is limited by retrospective collection, lack of validation and publication bias. Improved study design and reporting quality might accelerate successful development of personalized treatments in HNSCC.

Safety and efficacy of nivolumab, an anti-PD1 immunotherapy, in patients with advanced basal cell carcinoma, after failure or intolerance to sonic Hedgehog inhibitors: UNICANCER AcSé NIVOLUMAB trial

BACKGROUND

Basal cell carcinoma (BCC) is the most common human malignancy. In most cases, BCC has slow progression and can be definitively cured by surgery or radiotherapy. However, in rare cases, it can become locally advanced or, even more rarely, metastatic. The alternative recommended treatments are Sonic Hedgehog pathway inhibitors; however, the response is often short-lived.

METHODS

This was a phase 2 basket study (NCT03012581) evaluating the efficacy and safety of nivolumab in a cohort of 32 advanced BCC patients, enrolled after failure of Sonic Hedgehog inhibitors, including 29 laBCC (91%) and 3 mBCC (9%).

RESULTS

Compared to previously published studies, our population consisted of severe patients with a poor prognosis because they had already received multiple lines of treatment: all patients received previous Sonic Hedgehog inhibitors, 53% of patients already had chemotherapy and 75% radiotherapy. At 12 weeks, we reported 3.1% of complete responses, 18.8% of partial responses, and 43.8% of stable diseases. The best response rate to nivolumab reached 12.5% of complete responses (four patients), 18.8% of partial responses (three patients), and 43.8% of stable diseases (14 patients). Adverse events (AE) were mostly grade 2 or 3, slightly different to the adverse events observed in the treatment of metastatic melanoma (higher rate of diabetes, no thyroid dysfunction).

CONCLUSION

Nivolumab is a relevant therapeutic option for patients with advanced relapsing/refractory BCC.

Reinduction of Hedgehog Inhibitors after Checkpoint Inhibition in Advanced Basal Cell Carcinoma: A Series of 12 Patients

For patients with advanced basal cell carcinoma (aBCC) first-line treatment with hedgehog inhibitors (HHIs) and second-line treatment with PD1 inhibitors (PD1i) is available, offering combination and sequencing options. Here, we focus on the efficacy and safety of HHI reinduction after PD1i failure. Retrospective data analysis was performed with 12 patients with aBCC (locally advanced (n = 8)/metastatic (n = 4)). These patients (male:female 6:6, median age 68 years) initially received HHIs, leading to complete/partial response (66%) or stable disease (33%). Median treatment duration was 20.8 (2-64.5) months until discontinuation due to progression (n = 8), adverse events (n = 3), or patient request (n = 1). Subsequent PD1 inhibition (pembrolizumab 42%, cemiplimab 58%) yielded a partial response (8%), stable disease (33%), or progression (59%). Median treatment duration was 4.1 (0.8-16.3) months until discontinuation due to progression (n = 9), adverse events (n = 1), patient request (n = 1), or missing drug approval (n = 1). HHI reinduction resulted in complete/partial response (33%), stable disease (50%), or progression (17%). Median treatment duration was 3.6 (1-29) months. Response duration in the four responding patients was 2-29+ months. Thus, a subgroup of patients with aBCC responded to reinduction of HHI following PD1i failure. Therefore, this sequential treatment represents a feasible treatment option.

Sonidegib in the Treatment of Locally Advanced Basal Cell Carcinoma: a Retrospective Study

Sonidegib, a hedgehog pathway inhibitor, is indicated for treatment of locally advanced basal cell carcinoma, based on the results of the BOLT study. However, to date, no real-world study of sonidegib has been reported. An observational, retrospective, single-centre study (PaSoS study) was conducted. The primary objective was to evaluate the efficacy of sonidegib for treatment of locally advanced basal cell carcinoma in a real-world setting. Secondary objectives included modalities of use, tolerability, tumour evolution, and management after discontinuation. A total of 21 patients treated with sonidegib were included from March 2018 to January 2021. The median follow-up was 18.7 months and median exposure 7.0 months. Objective response (OR) rate was 81.0% (n = 17) including 6 (29%) patients with a complete response (CR). Disease control rate was 100%. First tumour response was rapid, with a median time of 2.3 months. Nine (43%) patients underwent surgery after sonidegib discontinuation, and no relapse was observed. All the patients experienced at least 1 adverse event (AE). Muscle spasms were the most frequent AE (n = 14; 67%), followed by dysgeusia (n = 8; 38%) and alopecia (n = 12; 57%). The efficacy and safety profile of sonidegib in this first-to-date real-life trial are consistent with prior results. Overall, real-world evidence corroborated sonidegib efficacy and tolerability as a first-line treatment for locally advanced basal cell carcinoma.

Clinical activity of PD-1 inhibition in the treatment of locally advanced or metastatic basal cell carcinoma

Background

Basal cell carcinoma (BCC) is the most common malignancy worldwide, yet the management of patients with advanced or metastatic disease is challenging, with limited treatment options. Recently, programmed death receptor 1 (PD-1) inhibition has demonstrated activity in BCC after prior Hedgehog inhibitor treatment.

Methods

We conducted a multicenter, retrospective analysis of BCC patients treated with PD-1 inhibitor therapy. We examined the efficacy and safety of PD-1 therapy, as well as clinical and pathological variables in association with outcomes. Progression-free survival (PFS), overall survival (OS) and duration of response (DOR) were calculated using Kaplan-Meier methodology. Toxicity was graded per Common Terminology Criteria for Adverse Events V.5.0.

Results

A total of 29 patients with BCC who were treated with PD-1 inhibition were included for analysis, including 20 (69.0%) with locally advanced and 9 (31.0%) with metastatic disease. The objective response rate was 31.0%, with five partial responses (17.2%), and four complete responses (13.8%). Nine patients had stable disease (31.0%), with a disease control rate of 62.1%. The median DOR was not reached. Median PFS was 12.2 months (95% CI 0.0 to 27.4). Median OS was 32.4 months (95% CI 18.1 to 46.7). Two patients (6.9%) developed grade 3 or higher toxicity, while four patients (13.8%) discontinued PD-1 inhibition because of toxicity. Higher platelets (p=0.022) and any grade toxicity (p=0.024) were significantly associated with disease control rate.

Conclusions

The clinical efficacy of PD-1 inhibition among patients with advanced or metastatic BCC in this real-world cohort were comparable to published trial data. Further investigation of PD-1 inhibition is needed to define its optimal role for patients with this disease.