Pembrolizumab in patients with rare and ultra-rare sarcomas (AcSé Pembrolizumab): analysis of a subgroup from a non-randomised, open-label, phase 2, basket trial.

BACKGROUND: Sarcoma is a heterogeneous group of diseases with few treatment options. Immunotherapy has shown little activity in studies including unselected sarcomas, but immune checkpoint blockers have shown activity in specific histotypes. We evaluated the activity of pembrolizumab in rare and ultra-rare sarcomas. METHODS: AcSé Pembrolizumab is an ongoing phase 2, basket, multitumour study investigating the activity of pembrolizumab monotherapy in rare cancers. Here, we report the results obtained in patients with selected histotypes of rare sarcomas (incidence of less than one case per 1 000 000 people per year) recruited at 24 French hospitals. Key inclusion criteria were age 15 years or older, Eastern Cooperative Oncology Group performance status of 0-1, and advanced disease that was untreated and resistant to treatment. Patients were given pembrolizumab 200 mg intravenously on day 1 of every 21-day cycle for a maximum of 24 months. The primary endpoint was objective response rate at week 12 using Response Evaluation Criteria in Solid Tumours version 1.1, assessed by local investigators. The primary endpoint and safety were analysed in the intention-to-treat population. The AcSé Pembrolizumab study is registered with ClinicalTrials.gov, NCT03012620. FINDINGS: Between Sept 4, 2017, and Dec 29, 2020, 98 patients were enrolled, of whom 97 received treatment and were included in analyses (median age 51 years [IQR 35-65]; 53 [55%] were male; 44 [45%] were female; no data were collected on race or ethnicity). 34 (35%) patients had chordomas, 14 (14%) had alveolar soft part sarcomas, 12 (12%) had SMARCA4-deficient sarcomas or malignant rhabdoid tumours, eight (8%) had desmoplastic small round cell tumours, six (6%) had epithelioid sarcomas, four (4%) had dendritic cell sarcomas, three (3%) each had clear cell sarcomas, solitary fibrous tumours, and myxoid liposarcomas, and ten (10%) had other ultra-rare histotypes. As of data cutoff (April 11, 2022), median follow-up was 13·1 months (range 0·1-52·8; IQR 4·3-19·7). At week 12, objective response rate was 6·2% (95% CI 2·3-13·0), with no complete responses and six partial responses in the 97 patients. The most common grade 3-4 adverse events were anaemia (eight [8%] of 97), alanine aminotransferase and aspartate aminotransferase increase (six [6%]), and dyspnoea (five [5%]). 86 serious adverse events were reported in 37 patients. Five deaths due to adverse events were reported, none of which were determined to be related to treatment (two due to disease progression, two due to cancer, and one due to unknown cause). INTERPRETATION: Our data show the activity and manageable toxicity of pembrolizumab in some rare and ultra-rare sarcoma histotypes, and support the PD-1/PD-L1 pathway as a potential therapeutic target in selected histotypes. The completion of the basket study will provide further evidence regarding the activity and toxicity of pembrolizumab in identified rare types of cancer. FUNDING: The Ligue contre le cancer, INCa, MSD. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

A non-inferiority randomized phase III trial of standard immunotherapy by checkpoint inhibitors vs. reduced dose intensity in responding patients with metastatic cancer: the MOIO protocol study.

BACKGROUND: Immunotherapy (IO) has become a standard of care for treating various types of metastatic cancers and has significantly improved clinical outcome. With the exception of metastatic melanoma in complete response for which treatment can be stopped at 6 months, these treatments are currently administered until either disease progression for some IO, 2 years for others, or unacceptable toxicity. However, a growing number of studies are reporting maintenance of response despite discontinuation of therapy. There is currently no evidence of a dose effect of IO in pharmacokinetic studies. Maintaining efficacy despite a reduction in treatment intensity by decreasing the frequency of administration in patients with highly selected metastatic cancer, is the hypothesis evaluated in the MOIO study. METHOD/DESIGN: This non-inferiority, randomized phase III study aims to compare the standard regimen to a 3 monthly regimen of variousIO drugs in adult patients with metastatic cancer in partial (PR) or complete response (CR) after 6 months of standard IO dosing (except melanoma in CR). This is a French national study conducted in 36 centers. The main objective is to demonstrate that the efficacy of a three-monthly administration is not unacceptably less efficacious than a standard administration. Secondary objectives are cost-effectiveness, quality of life (QOL), anxiety, fear of relapse, response rate, overall survival and toxicity. After 6 months of standard IO, patients with partial or complete response will be randomized 1:1 between standard IO or a reduced intensity dose of IO, administered every 3 months. The randomization will be stratified on therapy line,, tumor type, IO type and response status. The primary endpoint is the hazard ratio of progression-free survival. With a planned study duration of 6 years, including 36 months enrolment time, 646 patients are planned to demonstrate with a statistical level of evidence of 5% that the reduced IO regimen is non-inferior to the standard IO regimen, with a relative non-inferiority margin set at 1.3. DISCUSSION: Should the hypothesis of non-inferiority with an IO reduced dose intensity be validated, alternate scheduling could preserve efficacy while being cost-effective and allowing a reduction of the toxicity, with an increase in patient's QOL. TRIAL REGISTRATION: NCT05078047.

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.

Lnk adaptor protein down-regulates specific Kit-induced signaling pathways in primary mast cells.

Stem cell factor (SCF) plays critical roles in proliferation, survival, migration, and function of hematopoietic progenitor and mast cells through binding to Kit receptor. Previous studies have implicated the adaptor protein Lnk as an important negative regulator of SCF signaling. However, the molecular mechanism underlying this regulation is unclear. Here, we showed that the Src homology 2 domain (SH2) of Lnk binds directly and preferentially to phosphorylated tyrosine 567 in Kit juxtamembrane domain. Using Lnk(-/-) bone marrow mast cells (BMMCs) transduced with different Lnk proteins, we demonstrated that Lnk down-regulates SCF-induced proliferation with attenuation of mitogen-activated protein kinase (MAPK) and c-jun N-terminal kinase signaling. Furthermore, we showed that Lnk(-/-) BMMCs displayed increased SCF-dependent migration compared with wild-type cells, revealing a novel Lnk-mediated inhibitory function. This correlated with enhanced Rac and p38 MAPK activation. Finally, we found that Lnk domains and carboxy-terminal tyrosine contribute differently to inhibition of in vitro expansion of hematopoietic progenitors. Altogether, our results demonstrate that Lnk, through its binding to Kit tyrosine 567, negatively modulates specific SCF-dependent signaling pathways involved in the proliferation and migration of primary hematopoietic cells.