E. Routier

Safety profiles of anti-CTLA-4 and anti-PD-1 antibodies alone and in combination

Inhibition of immune checkpoints using anti-programmed cell death-1 (PD-1) or anti cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibodies has revolutionized the management of patients with advanced-stage melanoma and is among the most promising treatment approaches for many other cancers. Use of CTLA-4 and PD-1 inhibitors, either as single agents, or in combination, has been approved by the US FDA for the treatment of metastatic melanoma. Treatment with these novel immunotherapies results in a unique and distinct spectrum of adverse events, which are mostly related to activation of the immune system and are, therefore, an unwanted consequence of their mechanisms of action. Adverse effects of CTLA-4 and/or PD-1 inhibition are most commonly observed in the skin, gastrointestinal tract, liver and endocrine systems and include pruritus, rash, nausea, diarrhoea and thyroid disorders. In this Review, the authors describe the adverse event profile of checkpoint inhibitors targeting CTLA-4 and PD-1, used both as monotherapies and in combination and aim to provide some general guidelines, based upon the mechanisms of action of these therapies and on the management of these immune-related adverse events.

Experience in daily practice with ipilimumab for the treatment of patients with metastatic melanoma: an early increase in lymphocyte and eosinophil counts is associated with improved survival

BACKGROUND Ipilimumab is a recently approved immunotherapy that has demonstrated an improvement in the overall survival (OS) of patients with metastatic melanoma. We report a single-institution experience in patients treated in a compassionate-use program. PATIENTS AND METHODS In this prospective study, patients were treated between June 2010 and September 2011. Inclusion criteria were a diagnosis of unresectable stage III or IV melanoma, at least one previous line of chemotherapy, and survival 12 weeks after the first perfusion. Four courses of ipilimumab were administered at a dose of 3 mg/kg every 3 weeks. RESULTS Seventy-three patients were included. Median OS was 9.1 months (95% CI 6.4-11.3) from the start of ipilimumab. Immune-related adverse events were observed in 45 patients (62%), including 19 grade 3-4 events (26%). No drug-related death occurred. A lymphocyte count >1000/mm(3) at the start of the second course and an increase in the eosinophil count >100/mm(3) between the first and second infusions were correlated with an improved OS. CONCLUSION Ipilimumab toxic effect is manageable in real life. Biological data such as lymphocyte and eosinophil counts at the time of the second ipilimumab infusion appear to be early markers associated with better OS.

eIF4F is a nexus of resistance to anti-BRAF and anti-MEK cancer therapies

In BRAF(V600)-mutant tumours, most mechanisms of resistance to drugs that target the BRAF and/or MEK kinases rely on reactivation of the RAS–RAF–MEK–ERK mitogen-activated protein kinase (MAPK) signal transduction pathway, on activation of the alternative, PI(3)K–AKT–mTOR, pathway (which is ERK independent) or on modulation of the caspase-dependent apoptotic cascade. All three pathways converge to regulate the formation of the eIF4F eukaryotic translation initiation complex, which binds to the 7-methylguanylate cap (m7G) at the 5′ end of messenger RNA, thereby modulating the translation of specific mRNAs. Here we show that the persistent formation of the eIF4F complex, comprising the eIF4E cap-binding protein, the eIF4G scaffolding protein and the eIF4A RNA helicase, is associated with resistance to anti-BRAF, anti-MEK and anti-BRAF plus anti-MEK drug combinations in BRAF(V600)-mutant melanoma, colon and thyroid cancer cell lines. Resistance to treatment and maintenance of eIF4F complex formation is associated with one of three mechanisms: reactivation of MAPK signalling, persistent ERK-independent phosphorylation of the inhibitory eIF4E-binding protein 4EBP1 or increased pro-apoptotic BCL-2-modifying factor (BMF)-dependent degradation of eIF4G. The development of an in situ method to detect the eIF4E–eIF4G interactions shows that eIF4F complex formation is decreased in tumours that respond to anti-BRAF therapy and increased in resistant metastases compared to tumours before treatment. Strikingly, inhibiting the eIF4F complex, either by blocking the eIF4E–eIF4G interaction or by targeting eIF4A, synergizes with inhibiting BRAF(V600) to kill the cancer cells. eIF4F not only appears to be an indicator of both innate and acquired resistance but also is a promising therapeutic target. Combinations of drugs targeting BRAF (and/or MEK) and eIF4F may overcome most of the resistance mechanisms arising in BRAF(V600)-mutant cancers.

Association of Vitiligo With Tumor Response in Patients With Metastatic Melanoma Treated With Pembrolizumab

IMPORTANCE Vitiligo is an autoimmune skin disorder that reacts against melanocytes. The association of vitiligo with tumor response in patients with melanoma who undergo immunotherapy has been reported but is still controversial. OBJECTIVE To prospectively evaluate the appearance of vitiligo in patients receiving pembrolizumab, a monoclonal antibody directed against the programmed death cell receptor. DESIGN, SETTING, AND PARTICIPANTS This prospective observational study was conducted from January 1, 2012, through September 24, 2013, in a single tertiary care hospital with a unit dedicated to patients with melanoma. Sixty-seven patients with metastatic melanoma who received pembrolizumab treatment in the context of a phase 1 study were included and screened for the emergence of vitiligo. Data were collected from January 1, 2012, to February 28, 2014, and analyzed from February through December 2014. MAIN OUTCOMES AND MEASURES Objective tumor response with regard to the occurrence of vitiligo in patients receiving pembrolizumab therapy. Correlation between vitiligo occurrence and overall survival was also estimated using the Kaplan-Meier product-limit method and compared with a log-rank test. To prevent guarantee- or lead-time bias, a landmark analysis approach after 12, 16, and 20 weeks of treatment was retained. RESULTS Of the 67 patients included in the study, 17 (25%) developed vitiligo during pembrolizumab treatment and 50 (75%) did not. An objective (complete or partial) response to treatment was associated with a higher occurrence of vitiligo (12 of 17 [71%] vs 14 of 50 [28%]; P = .002). The time to onset of vitiligo ranged from 52 to 453 (median, 126) days from the start of treatment. Of the 17 patients with vitiligo, 3 (18%) had a complete response, 9 (53%) had a partial response, 3 (18%) had stable disease, and 2 (12%) had progressive disease at the final follow-up. All the patients treated with pembrolizumab who developed vitiligo were alive at the time of analysis, with a median follow-up of 441 days. CONCLUSIONS AND RELEVANCE Vitiligo, a clinically visible immune-related adverse event could be associated with clinical benefit in the context of pembrolizumab treatment.

Kidney injuries related to ipilimumab

SummaryMonoclonal antibodies directed against the immune checkpoint protein cytotoxic T-lymphocyte antigen-4 (CTLA-4; CD152) have been investigated in metastatic melanoma and other cancers and have shown promising results. Inhibition of CTLA-4 characteristically induces well-known side effects called “immune-related adverse events” (irAEs). IrAEs mainly include colitis, dermatitis, hepatitis, endocrinopathies; uveitis, iridocyclitis, neuropathies, and inflammatory myopathy have occasionally been reported. Kidney involvement is rare. We report 2 cases of acute granulomatous interstitial nephritis and present, based on literature review, renal disorders related to Ipilimumab therapy. Autoimmune symptoms have to be carefully checked for patients treated with CTLA-4 inhibitors. In order to reduce the risk of sequelae, early recognition of irAEs and treatment initiation are crucial.

First-in-Human, Phase I Dose-Escalation Study of the Safety, Pharmacokinetics, and Pharmacodynamics of RO5126766, a First-in-Class Dual MEK/RAF Inhibitor in Patients with Solid Tumors

Purpose: This phase I study assessed the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), safety, pharmacokinetics, pharmacodynamics, and clinical activity of the first-in-class dual MEK/RAF inhibitor, RO5126766. Experimental Design: Initial dose-escalation was conducted using once daily dosing over 28 consecutive days in 4-week cycles. Further escalation was completed using 2 intermittent dosing schedules [7 days on treatment followed by 7 days off (7on/7off); 4 days on treatment followed by 3 days off (4on/3off)]. Results: Fifty-two patients received RO5126766 at doses of 0.1 to 2.7 mg once daily, 2.7 to 4.0 mg (4 on/3 off), or 2.7 to 5.0 mg (7 on/7 off). The most common DLTs were elevated creatine phosphokinase (CPK) and blurred vision. The MTD for each dosing schedule was 2.25 mg once daily, 4.0 mg (4 on/3 off), and 2.7 mg (7 on/7 off). The dose/schedule recommended for phase II (RP2D) investigation was 2.7 mg (4 on/3 off). Frequent adverse events included rash-related disorders (94.2%), elevated CPK (55.8%), and diarrhea (51.9%). Cmax occurred 1 to 2 hours after dosing and mean terminal half-life was approximately 60 hours. Pharmacodynamic changes included reduced ERK phosphorylation, an increase in apoptosis in tumor tissue, and a reduction in fluorodeoxyglucose (FDG) uptake after 15 days of dosing. Three partial responses were seen: two in BRAF-mutant melanoma tumors and one in an NRAS-mutant melanoma. Conclusion: This first-in-human study shows that oral RO5126766 has manageable toxicity, a favorable pharmacokinetic/pharmacodynamic profile, and encouraging preliminary antitumor activity in this population of heavily pretreated patients, achieving tumor shrinkage in around 40% of patients across all dose levels and all tumor types. Clin Cancer Res; 18(17); 4806–19. ©2012 AACR.

Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab

Background Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity. Patients and methods Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel. Results A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A. Conclusion Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.

Vemurafenib and Radiosensitization

IMPORTANCE The BRAF inhibitor, vemurafenib, was recently approved for the treatment of patients with BRAFV600 metastatic melanoma. Wider use of this drug and longer follow-up periods of treatment are resulting in the emergence of a growing number of reports detailing new adverse effects. Cutaneous adverse effects are preeminent with UV-A-dependent phototoxicity, hyperkeratotic folliculitis, hand-foot skin reaction, hair changes, verrucous papillomas, keratoacanthomas, and squamous cell carcinomas. OBSERVATIONS We report 2 cases of dermatitis occurring on a previously irradiated skin area in patients treated with vemurafenib for a BRAFV600-mutated metastatic melanoma. The first case occurred 10 days after a low dose of radiation was delivered that usually does not induce any radiodermatitis, suggesting radiosensitization by vemurafenib. The second case occurred 30 days after radiotherapy and was diagnosed as radiation recall dermatitis. CONCLUSIONS AND RELEVANCE Vemurafenib should be considered a potential cutaneous radiosensitizer and an inducer of radiation recall dermatitis. However, these adverse effects are easily managed with topical corticosteroids. Dose reduction or interruption of vemurafenib is not required. Further studies and reports will enlighten us as to whether this pharmacodynamic interaction between x-rays and vemurafenib is also seen with other BRAF or MEK inhibitors on the same mitogen-activated protein kinase pathway currently under development.

Secondary Tumors Arising in Patients Undergoing BRAF Inhibitor Therapy Exhibit Increased BRAF–CRAF Heterodimerization

BRAF inhibitors (BRAFi) elicit therapeutic responses in metastatic melanoma, but alarmingly, also induce the formation of secondary benign and malignant skin tumors. Here, we report the emergence and molecular characterization of 73 skin and extracutaneous tumors in 31 patients who underwent BRAFi therapy. The majority of patients presented with classic epidermal tumors such as verrucous papillomas, keratoacanthomas, and squamous cell carcinomas (SCC). However, 15 patients exhibited new or rapidly progressing tumors distinct from these classic subtypes, such as lymph node metastasis, new melanomas, and genital and oral mucosal SCCs. Genotyping of the tumors revealed that oncogenic RAS mutations were found in 58% of the evaluable tumor samples (38/66) and 49% of the control tumors from patients not treated with BRAFi (30/62). Notably, proximity ligation assays demonstrated that BRAF-CRAF heterodimerization was increased in fixed tumor samples from BRAFi-treated patients compared with untreated patients. Our findings reveal that BRAF-CRAF complex formation is significantly associated with BRAFi treatment, and may therefore serve as a useful biomarker of BRAFi-induced cutaneous and extracutaneous tumor formation.

Onset of connective tissue disease following anti-PD1/PD-L1 cancer immunotherapy

Although treatment with immune checkpoint inhibitors (ICIs) is associated with better survival in many cancer settings, these therapeutics can induce immune-related adverse events (IrAEs).1 ,2 REISAMICi is a French, prospective, multicentre, academic registry sponsored by the Gustave Roussy Institute cancer centre. The objective is to better detect, document and manage IrAEs. Connective tissue diseases (CTD) have not previously been reported in patients treated with anti-PD1/PDL-1 agents. The REISAMIC registry was screened for reports of CTD. Of the 447 patients supervised in the REISAMIC registry, three have developed CTD: two cases of Sjogrens syndrome and one case of cryoglobulinemic vasculitis as a complication of suspected Sjogrens syndrome (table 1). A case of ANA+ myositis registered in REISAMIC by another investigating centre …