Antibiotic Treatment is an Independent Poor Risk Factor in NSCLC But Not in Melanoma Patients Who had Received Anti-PD-1/L1 Monotherapy.

BACKGROUND: Antibiotic treatment may reduce the efficacy of cancer immunotherapy by disrupting gut microbiome. We aimed to study the association of antibiotics and survival outcomes in advanced cutaneous melanoma and non-small-cell lung cancer (NSCLC) patients who had received anti-PD-1/L1 monotherapy. PATIENTS AND METHODS: A total of 222 melanoma and 199 NSCLC patients had received anti-PD-1/L1 monotherapy in 5 Finnish hospitals between January 2014 and December 2020. Clinical characteristics, antibiotic and corticosteroid treatment, and survival outcomes were retrospectively collected from hospital and national medical records. RESULTS: There were 32% of melanoma and 31% of NSCLC patients who had received antibiotic treatment (ABT) 3 months before to 1 month after the first anti-PD-1/L1 antibody infusion. In survival analyses, early antibiotic treatment was associated with inferior overall survival (OS) (ABT 19.2 [17.6-43.7] vs. no ABT 35.6 [29.3-NA] months, P = .033) but not with inferior progression-free survival (PFS) (ABT 5.8 [3.0-12.6] vs. no ABT 10.2 [7.7-15.3] months, P = .3) in melanoma patients and with inferior OS (ABT 8.6 [6.4-12.3] vs. no ABT 18.5 [15.1-21.6] months, P < .001) and PFS (ABT 2.8 [2.1-4.5] vs. no ABT 5.6 [4.4-8.0] months, P = .0081) in NSCLC patients. In multivariable analyses, ABT was not an independent risk-factor for inferior OS and PFS in melanoma but was associated with inferior OS (hazard ratio [HR] 2.12 [1.37-3.28]) and PFS (HR 1.65 [1.10-2.47]) in NSCLC after adjusted for other risk factors. CONCLUSIONS: Early ABT was an independent poor risk factor in NSCLC patients who had received anti-PD-1/L1 monotherapy but not in melanoma patients. The weight of ABT as a poor risk factor might depend on other prognostic factors in different cancers.

Circulating tumor DNA is a prognostic biomarker in metastatic melanoma patients treated with chemoimmunotherapy and BRAF inhibitor.

BACKGROUND: Detectable circulating tumor DNA (ctDNA) has been associated with worse prognosis in melanoma patients. MATERIAL AND METHODS: We studied plasma ctDNA as a prognostic biomarker in 19 patients with metastatic melanoma and a detectable tumor mutation (13 BRAF, 5 NRAS, and 1 KRAS). Patients had received chemotherapy, interferon-alpha, and vemurafenib in a prospective clinical trial. Mutant allele frequency (MAF %) was determined with droplet digital PCR from pretreatment and sequential plasma samples. RESULTS: Higher pretreatment plasma ctDNA levels (MAF ≥3%) and detectable plasma ctDNA levels (MAF >0%) at the time of radiologically confirmed best objective response were associated with poor prognosis even when accounting for other relevant prognostic factors including performance status, tumor mutation, metastasis stage, and lactate dehydrogenase levels in multivariable analysis. CONCLUSION: Higher pretreatment plasma ctDNA levels and sustained detectable plasma ctDNA levels during treatment indicated poor prognosis in metastatic melanoma patients.

High-throughput ex vivo drug testing identifies potential drugs and drug combinations for NRAS-positive malignant melanoma.

Therapy options for patients with metastatic melanoma (MM) have considerably improved over the past decade. However, many patients still need effective therapy after unsuccessful immunotherapy, especially patients with BRAF-negative tumors who lack the option of targeted treatment second line. Therefore, the elucidation of efficient and personalized therapy options for these patients is required. In this study, three patient-derived cancer cells (PDCs) were established from NRAS Q61-positive MM patients. The response of PDCs and five established melanoma cell lines (two NRAS-positive, one wild type, and two BRAF V600-positive) was evaluated toward a panel of 527 oncology drugs using high-throughput drug sensitivity and resistance testing. The PDCs and cell lines displayed strong responses to MAPK inhibitors, as expected. Additionally, the PDCs and cell lines were responsive to PI3K/mTOR, mTOR, and PLK1 inhibitors among other effective drugs currently undergoing clinical trials. Combinations with a MEK inhibitor were tested with other targeted agents to identify effective synergies. MEK inhibitor showed synergy with multikinase inhibitor ponatinib, ABL inhibitor nilotinib, PI3K/mTOR inhibitor pictilisib, and pan-RAF inhibitor LY3009120. The application of the patients' cancer cells for functional drug testing ex vivo is one step further in the process of identifying potential agents and agent combinations to personalize treatment for patients with MM. Our preliminary study results suggest that this approach has the potential for larger-scale drug testing and personalized treatment applications in our expansion trial. Our results show that drug sensitivity and resistance testing may be implementable in the treatment planning of patients with MM.

Isolated limb perfusion with melphalan as treatment for regionally advanced melanoma of the limbs: results of 60 patients treated in Finland during 2007-2018.

Isolated limb perfusion (ILP) is widely accepted as treatment for recurrent melanoma limited to the limbs. The use of ILP has decreased in recent years with the introduction of potentially effective new systemic therapies. We evaluated retrospectively if ILP still may be a treatment option in locally advanced melanoma. In Finland, ILP is centralized to the Comprehensive Cancer Center of Helsinki University Hospital. We included all ILP patients treated at our hospital between 2007 and 2018. Clinical factors and treatment outcomes were retrospectively evaluated. Altogether 60 patients received ILP. Toxicity was mostly transient. The overall response rate was 77% with 35% complete responses and 42% partial responses. The median progression-free survival (PFS) was 6.1 months (range 0.6-116.5 months) and the median melanoma-specific survival (MSS) was 29.9 months (range 3.5-138.7 months). Patients with CR had superior median PFS (19.7 months, range 2.5-116.5 vs. 4.5 months, range 0.6-39.7 months, P = 0.00003) and median MSS (median MSS not reached vs. 25.9 months, range 3.5-98.7 months, P = 0.0005) compared to other responders. Younger patients (<69 years) had longer median MSS (47.2 months, range 3.5-138.7 vs. 25.9 months, range 8.4-125.4 months, P = 0.015) compared to patients over 69 years. Treatment outcomes of Finnish ILP patients were comparable to earlier studies and some long-term survivors were observed in the group of complete responders. Median PFS and OS were longer for patients achieving a CR. Treatment was well-tolerated also among older patients.

BRAF inhibitor treatment is feasible in the oldest-old advanced melanoma patients.

Although new compounds have improved the treatment landscape of metastatic melanoma, very limited data exist on the efficacy and safety of treating older patients with novel agents. Here, we provide results of BRAF (BRAFi) ± MEK (MEKi) inhibitor treatment in patients over 75 years (oldest-old patients) with metastatic melanoma. Between 2011 and 2020, 34 consecutive patients with metastatic melanoma over 75 years of age (range 75-89) were treated with BRAFi ± MEKi at the Comprehensive Cancer Center of Helsinki University Hospital. Data on clinical and histopathological features, toxicity, response rate (RR), progression-free survival (PFS) and overall survival (OS) were collected. Patients were treated with BRAFi (n = 22) or BRAFi in combination with MEK inhibitor (MEKi) (n = 12). Grade 1-2 adverse events occurred in 68% of the patients, 32% had grade 3 adverse effects, dose reductions were made for 41% of patients and 29% terminated treatment due to toxicity. Overall, the RR was 62%. Complete responses were achieved in 27% of the patients, and 35% had partial responses. The median PFS was 8 months (range 0-57), and the median OS was 15 months (range 0-71). Tailored BRAFi ± MEKi treatment for older patients is feasible. Adverse effects occur frequently but are manageable by dose adjustment. The occurrence of toxicity of monotherapy was similar to that of combination therapy. The RR and median OS from our retrospective study are comparable with those reported in clinical trials and combination therapy produced somewhat more and longer-lasting responses. Hence, it seems that older patients may benefit from BRAFi treatment.

Age-associated changes in the immune system may influence the response to anti-PD1 therapy in metastatic melanoma patients.

Anti-PD1 treatment has improved the survival of metastatic melanoma patients, yet it is unknown which patients benefit from the treatment. In this exploratory study, we aimed to understand the effects of anti-PD1 therapy on the patients' immune system and discover the characteristics that would result in successful treatment. We collected peripheral blood (PB) samples from 17 immuno-oncology-naïve metastatic melanoma patients before and after 1 and 3 months of anti-PD1 therapy. In addition, matching tumor biopsies at the time of diagnosis were collected for tissue microarray. The complete blood counts, PB immunophenotype, serum cytokine profiles, and tumor-infiltrating lymphocytes were analyzed and correlated with the clinical data. Patients were categorized based on their disease control into responders (complete response, partial response, stable disease > 6 months, N = 11) and non-responders (progressive disease, stable disease ≤ 6 months, N = 6). During therapy, the PB natural killer T (NKT) cell frequency, expression of CD25 and CD45RO on cytotoxic natural killer (NK) cells, and serum CXC chemokine levels were significantly increased in responders. Furthermore, higher age together with age-associated characteristics from PB, lower frequency of PB-naïve CD8+ T cells, and elevated levels of serum MCP-4 and OPG were discovered as baseline predictors of treatment response. We therefore propose that in addition to T cells, anti-PD1 treatment is associated with NK- and NKT-cell population dynamics, and that the age-associated characteristics from PB together with older age may contribute to prolonged PFS in anti-PD1-treated melanoma patients.

Limited-duration anti-PD-1 therapy for patients with metastatic melanoma.

Purpose: To date, no clinical study has reported on the optimal treatment duration of PD-1 blockade in patients with metastatic melanoma. Worldwide, concern has been expressed that due to the high cost of anti-PD-1 therapy, it is not available for all patients. After approval of anti-PD-1 therapy as a first-line treatment, the Helsinki University Hospital institutional board for new drugs decided to treat the first patient cohort within a limited treatment duration program in order to offer this treatment to as many patients as possible.Patients and methods: The first 40 patients with metastatic melanoma initiating treatment at Helsinki University Hospital were to be treated within a six months maximum limited duration program. Patient follow-up was systematic according to a prospectively planned treatment protocol to enable evaluation of treatment efficacy and the safety of this treatment approach.Results: Thirty-eight patients were treated within the program. Seventeen out of these 38 patients completed the six-month regimen. Five discontinued treatment early due to toxicity, and 16 discontinued due to progressive disease. The response rate (RR) for all patients was 39%, but only 33% of these responses are ongoing. Median progression-free survival (PFS) for patients who completed the six-month therapy was 12 months (range, two to 44 months), and median overall survival (OS) has not yet been reached.Conclusions: Although RR is comparable to published data, the response duration is shorter. Based on our results, limiting treatment to only six months may increase the risk of shortening response duration.