Assessment of Retinal Pigment Epithelium Alterations and Chorioretinal Vascular Network Analyses in Patients under Treatment with BRAF/MEK Inhibitor for Different Malignancies: A Pilot Study

In the last two decades, an increasing number of so-called molecular-targeted therapies have become available for the treatment of patients with advanced malignancies. These drugs have included inhibitors of proteins in the MAPK pathway, such as BRAF and MEK inhibitors, which are characterized by a distinct toxicity profile. The eye is particularly susceptible to adverse effects due to MEK inhibitors, and the term MEKAR (MEK-inhibitor-associated retinopathy) indicates the presence of subretinal fluid, mimicking central serous chorioretinopathy (CSC). The pathogenesis of the retinal alterations related to MAPK pathway inhibitors is still unclear, and questions are still open. The present study aims to assess the presence of retinal pigment epithelium alterations as predictive parameters for retinal toxicity, analyzing, at the same time, the chorioretinal vascular network in patients undergoing BRAF/MEK inhibitor treatment for different malignancies.

P06.05.A Repeated intracranial administration of ipilimumab and nivolumab in patients with recurrent glioblastoma (rGB): A multi-cohort adaptive phase I clinical trial

Background

Perioperative intracerebral (iCE) administration of ipilimumab (IPI) and nivolumab (NIVO) in combination with IV NIVO was shown to be feasible, safe and associated with an encouraging survival benefit (Duerinck et al. JITC 2021). In subsequent cohorts, combination of iCE administration with biweekly intracavitary (iCA, via an Ommaya reservoir) administration of increasing doses of IPI and NIVO was investigated.

Methods

Three cohorts were defined according to resectability and postoperative treatment schedule. Patients (pts) in cohort-A and -C underwent a maximal safe resection, pts in cohort-B stereotactic biopsy only. All pts received iCE administration of 10 mg NIVO and 5 mg IPI at the end of the surgical intervention, after which an OR was implanted and an additional 10mg of NIVO and IPI (1, 5 or 10 mg) was administered iCA in cohort-C. All pts received biweekly postoperative NIVO 10 mg IV and iCA administrations of NIVO (3 dose levels were investigated in cohorts-A and -B: 1, 5, or 10 mg) for up to a maximum of 24w postoperatively. In cohort-C, 10 mg of NIVO was complemented with IPI (1, 5, or 10 mg). NGS and RNA gene expression profiling was performed on all tissue samples.

Results

In total, 44 pts were included (A: n= 16, B: n= 16, C: n= 12 recruitment ongoing). All pts in cohort-A and -B are off study treatment. All pts received the predefined dose of iCE IPI/NIVO and at least one administration of the predefined iCA dose. AE were infrequent and mostly not immune-related. Most common AE were fatigue(n=37), headache(n=25), confusion(n=18) and postoperative fever(n=15). Bacterial colonization of the Ommaya port occurred in 6 pts, subacute neurological deterioration requiring corticosteroids in 8 pts. There were no grade 5 AEs. Median PFS was 13w for cohort-A, 5w in cohort-B and 13w in cohort-C. Median OS is 43weeks in A, 29w in B and is not yet reached in cohort-C after median follow-up of 23w. OS did not differ significantly between study cohorts. OS of pts who underwent surgical resection (cohorts-A and -C) compared favorably to a historical cohort of 469 Belgian patients with rGB (treated in three prospective phase II clinical trials and a large multicenter early acces program for bevacizumab).

Conclusions

iCE followed by repeated iCA administrations of increasing doses of NIVO with/without IPI in rGB is feasible and safe without dose limiting AEs. A potential survival benefit seems restricted to pts amenable to surgical resection.

Intratumoral administration of CD1c (BDCA-1)+ and CD141 (BDCA-3)+ myeloid dendritic cells in combination with talimogene laherparepvec in immune checkpoint blockade refractory advanced melanoma patients: a phase I clinical trial

BACKGROUND

Intratumoral (IT) myeloid dendritic cells (myDCs) play a pivotal role in initiating antitumor immune responses and relicensing of anti-tumor cytotoxic T lymphocytes within the tumor microenvironment. Talimogene laherparepvec (T-VEC) induces immunogenic cell death, thereby providing maturation signals and enhancing the release of tumor antigens that can be captured and processed by CD1c (BDCA-1)⁺ / CD141 (BDCA-3)⁺ myDCs, in order to reinvigorate the cancer-immunity cycle.

METHODS

In this phase I trial, patients with advanced melanoma who failed standard therapy were eligible for IT injections of ≥1 non-visceral metastases with T-VEC on day 1 followed by IT injection of CD1c (BDCA-1)⁺ myDCs +/- CD141 (BDCA-3)⁺ myDCs on day 2. T-VEC injections were repeated on day 21 and every 14 days thereafter. The number of IT administered CD1c (BDCA-1)⁺ myDCs was escalated from 0.5×10⁶, to 1×10⁶, to a maximum of 10×10⁶ cells in three sequential cohorts. In cohort 4, all isolated CD1c (BDCA-1)⁺ / CD141 (BDCA-3)⁺ myDCs were used for IT injection. Primary objectives were safety and feasibility. Repetitive biopsies of treated lesions were performed.

RESULTS

In total, 13 patients were enrolled (cohort 1 n=2; cohort 2 n=2; cohort 3 n=3; cohort 4 n=6). Patients received a median of 6 (range 3-8) T-VEC injections. The treatment was safe with most frequent adverse events being fatigue (n=11 (85%)), fever (n=8 (62%)), and chills/influenza-like symptoms (n=6 (46%)). Nine (69%) and four patients (31%), respectively, experienced pain or redness at the injection-site. Clinical responses were documented in injected and non-injected lesions. Two patients (cohort 3) who previously progressed on anti-PD-1 therapy (and one patient also on anti-CTLA-4 therapy) developed a durable, pathologically confirmed complete response that is ongoing at 33 and 35 months following initiation of study treatment. One additional patient treated (cohort 4) had an unconfirmed partial response as best response; two additional patients had a mixed response (with durable complete responses of some injected and non-injected lesions). On-treatment biopsies revealed a strong infiltration by inflammatory cells in regressing lesions.

CONCLUSIONS

IT coinjection of autologous CD1c (BDCA-1)⁺ +/- CD141 (BDCA-3)⁺ myDCs with T-VEC is feasible, tolerable and resulted in encouraging early signs of antitumor activity in immune checkpoint inhibitor-refractory melanoma patients.

TRIAL REGISTRATION NUMBER

NCT03747744.

A phase I clinical trial on intracranial administration of autologous myeloid dendritic cells (myDC) in combination with ipilimumab and nivolumab in patients with recurrent glioblastoma (rGB)

2033

Background: Intracerebral administration of ipilimumab (IPI) and nivolumab (NIVO) following resection of rGB was demonstrated to be safe and resulted in encouraging survival (Duerinck, Schwarze et al. JITC 2021; Neyns et al. ESMO 2021). CD1c(BDCA-1)+ and CD141(BDCA-3)+ myDC play a pivotal role in initiating an adaptive anti-tumor immune response by re-licensing cytotoxic T lymphocytes within the tumor microenvironment. Methods: Eligible patients (pts)(diagnosed with rGB following radiation and temozolomide treatment; not in need of steroids) underwent a leukapheresis followed by immunomagnetic bead isolation and cryopreservation of CD1c (BDCA-1)+ / CD141(BDCA-3)+ myDC. At the time of surgery, an escalating number of myDC (1, 10, and 20x106 myDC) were injected into the brain tissue lining the resection cavity following maximal safe resection of the rGB (ICer) or injected intratumorally (ITum) following stereotactic biopsy (STx). IPI (5 mg) plus NIVO (10 mg) were co-injected with myDC. NIVO was administered intracavitary (ICav, 10mg) using an Ommaya port and intravenously (IV, 10mg) Q2w (max 12x). Results: Fourteen pts (9 male; median 48y [range 20-78]) were recruited (resection n = 11; STx n = 2) and underwent a successful leukapheresis and isolation of myDC; peroperative administration of myDC was preceded by resection in 10 pts (1 pt did not undergo surgery due to clinical deterioration/cerebral edema), and by STx in 2 pts. Respectively 6 (incl both pts who underwent a STx), 3, and 4 pts were treated at the 3 dose levels. All pts received ITum/ICer/IV-administrations of IPI and NIVO as planned. Median number of postoperative ICav/IV NIVO-administrations was 7 (range 2-11). Most frequent adverse events (AE) were headache (n = 11), fatigue (n = 9), transient dysphasia (n = 6), and nausea (n = 5). Bacterial colonization of the Ommaya occurred in 3 pts necessitating removal. Immune-related AE were infrequent and mild. No G5 AE occurred. No dose-limiting toxicities were seen with increasing numbers of myDC. After a median follow-up of 54w, 3 pts remain progression-free (after 42+, 51+, 54+ weeks of FU), 6 (46%) pts have died; median PFS is 13w (95% CI 0-26), median OS has not been reached; 6-months PFS- and OS-rate are respectively 30% and 84%, 12-months PFS- and OS-rate are respectively 23% and 51%. OS compares favorably to an historical cohort of Belgian rGB patients (n = 469; Log-Rank p = 0.018). Gene expression profiling of resected tissue, analysis of cellular counts, cytokines, NIVO/IPI-concentrations in on-treatment cerebrospinal fluid samples is ongoing. Conclusions: Intracranial administration of autologous myDC plus IPI and NIVO in combination with IV NIVO was found to be feasible, sufficiently safe and associated with encouraging survival justifying further investigation in pts with resectable rGB. Clinical trial information: NCT03233152.

A lead-in safety study followed by a phase 2 clinical trial of dabrafenib, trametinib and hydroxychloroquine in advanced BRAFV600 mutant melanoma patients previously treated with BRAF-/MEK-inhibitors and immune checkpoint inhibitors

Patients with advanced BRAFV600 mutant melanoma who progressed on prior treatment with BRAF-/MEK-inhibitors and programmed cell death 1 or cytotoxic T-lymphocyte-associated antigen 4 immune checkpoint inhibitors can benefit from retreatment with the combination of a BRAF- and a MEK-inhibitor ('rechallenge'). Hydroxychloroquine can prevent autophagy-driven resistance and improve the efficacy of BRAF-/MEK-inhibitors in preclinical melanoma models. This clinical trial investigated the use of combined BRAF-/MEK-inhibition with dabrafenib and trametinib plus hydroxychloroquine in patients with advanced BRAFV600 mutant melanoma who previously progressed on prior treatment with BRAF-/MEK-inhibitors and immune checkpoint inhibitors. Following a safety lead-in phase, patients were randomized in the phase 2 part of the trial between upfront treatment with dabrafenib, trametinib and hydroxychloroquine (experimental arm), or dabrafenib and trametinib, with the possibility to add-on hydroxychloroquine at the time of documented tumor progression (contemporary control arm). Ten and four patients were recruited to the experimental and contemporary control arm, respectively. The objective response rate was 20.0% and the disease control rate was 50.0% in the experimental arm, whereas no responses were observed before or after adding hydroxychloroquine in the contemporary control arm. No new safety signals were observed for dabrafenib and trametinib. Hydroxychloroquine was suspected of causing an anxiety/psychotic disorder in one patient. Based on an early negative evaluation of the risk/benefit ratio for adding hydroxychloroquine to dabrafenib and trametinib when 'rechallenging' BRAFV600mutant melanoma patients, recruitment to the trial was closed prematurely.

Melanoma with genetic alterations beyond the BRAFV600 mutation: management and new insights

PURPOSE OF REVIEW

Molecular-targeted therapy with BRAF-/MEK-inhibitors has shown impressive activity in patients with advanced BRAFV600 mutant melanoma. In this review, we aim to summarize recent data and possible future therapeutic strategies involving small-molecule molecular-targeted therapies for advanced BRAFV600 wild-type melanoma.

RECENT FINDINGS

In patients with NRASQ61 mutant melanoma, downstream MEK-inhibition has shown some albeit low activity. MEK-inhibitors combined with novel RAF dimer inhibitors, such as belvarafenib, or with CDK4/6-inhibitors have promising activity in NRAS mutant melanoma in early-phase trials. In patients with non-V600 BRAF mutant melanoma, MEK-inhibition with or without BRAF-inhibition appears to be effective, although large-scale prospective trials are lacking. As non-V600 BRAF mutants signal as dimers, novel RAF dimer inhibitors are also under investigation in this setting. MEK-inhibition is under investigation in NF1 mutant melanoma. Finally, in patients with BRAF/NRAS/NF1 wild-type melanoma, imatinib or nilotinib can be effective in cKIT mutant melanoma. Despite preclinical data suggesting synergistic activity, the combination of the MEK-inhibitor cobimetinib with the immune checkpoint inhibitor atezolizumab was not superior to the immune checkpoint inhibitor pembrolizumab.

SUMMARY

As of today, no molecular-targeted therapies have shown to improve survival in patients with advanced BRAFV600 wild-type melanoma. Combinatorial strategies, involving MEK-inhibitors, RAF dimer inhibitors and CDK4/6-inhibitors, are currently under investigation and have promising activity in advanced BRAFV600 wild-type melanoma.

COVID-19 and Cushing's disease in a patient with ACTH-secreting pituitary carcinoma

SUMMARY

The pandemic caused by severe acute respiratory syndrome coronavirus 2 is of an unprecedented magnitude and has made it challenging to properly treat patients with urgent or rare endocrine disorders. Little is known about the risk of coronavirus disease 2019 (COVID-19) in patients with rare endocrine malignancies, such as pituitary carcinoma. We describe the case of a 43-year-old patient with adrenocorticotrophic hormone-secreting pituitary carcinoma who developed a severe COVID-19 infection. He had stabilized Cushing's disease after multiple lines of treatment and was currently receiving maintenance immunotherapy with nivolumab (240 mg every 2 weeks) and steroidogenesis inhibition with ketoconazole (800 mg daily). On admission, he was urgently intubated for respiratory exhaustion. Supplementation of corticosteroid requirements consisted of high-dose dexamethasone, in analogy with the RECOVERY trial, followed by the reintroduction of ketoconazole under the coverage of a hydrocortisone stress regimen, which was continued at a dose depending on the current level of stress. He had a prolonged and complicated stay at the intensive care unit but was eventually discharged and able to continue his rehabilitation. The case points out that multiple risk factors for severe COVID-19 are present in patients with Cushing's syndrome. 'Block-replacement' therapy with suppression of endogenous steroidogenesis and supplementation of corticosteroid requirements might be preferred in this patient population.

LEARNING POINTS

Comorbidities for severe coronavirus disease 2019 (COVID-19) are frequently present in patients with Cushing's syndrome. 'Block-replacement' with suppression of endogenous steroidogenesis and supplementation of corticosteroid requirements might be preferred to reduce the need for biochemical monitoring and avoid adrenal insufficiency. The optimal corticosteroid dose/choice for COVID-19 is unclear, especially in patients with endogenous glucocorticoid excess. First-line surgery vs initial disease control with steroidogenesis inhibitors for Cushing's disease should be discussed depending on the current healthcare situation.

CTIM-17. INTRA-CRANIAL ADMINISTRATION OF CTLA-4 AND PD-1 IMMUNE CHECKPOINT-INHIBITING MONOCLONAL ANTIBODIES IN RECURRENT GLIOBLASTOMA PATIENTS: A MULTI-COHORT ADAPTIVE PHASE I CLINICAL TRIAL

BACKGROUND: Intracerebral (iCE) administration of nivolumab (NIVO) and ipilimumab (IPI) after resection of recurrent glioblastoma (rGB), followed by repeated intravenous(IV) NIVO was recently shown to be feasible, safe and associated with encouraging survival. Subsequent cohorts were defined to investigate the addition of biweekly intracavitary (iCA) or intrathecal (iTH) NIVO +/- IPI administrations. METHODS Four groups were defined according to rGB resectability and postoperative treatment schedule. Group A and D underwent biopsy, B and C maximal safe resection. All patients received iCE injections of 10 mg/1ml NIVO + 5 mg/1ml IPI at the end of surgery, after which an Ommaya catheter was implanted iCA (A, B and C) or iTH (D). Following surgery, all patients received biweekly IV low-dose NIVO(10mg) combined with iCA/iTH 10 mg NIVO (A and B) + 1, 5 or 10 mg IPI (C and D) for up to 24 weeks. NIVO/IPI concentrations were dosed in the cerebrospinal fluid (CSF). Gene sequencing and RNA gene expression profiling were performed on all tissue samples RESULTS 39pts(27 male; 16 in A, 16 in B, 4 in C, 3 in D; recruitment ongoing in C+D) were enrolled. All patients received the predefined dose of iCE IPI/NIVO. Most frequent AEs were fatigue (n=30), headache (n=19), confusion (n=14), dysphasia (n=13), and fever (n=10). Ommaya infection occurred in 5patients, subacute neurological deterioration requiring corticosteroids in 6patients. There were no G5 AEs. irAEs were infrequent and mild. Median PFS and OS were 5w(95% CI 1-8) and 23w(95% CI 0-53) in A and 13w(95% CI 7-19) and 42w(95% CI 30-54) in B, respectively. >90% of CSF samples had elevated protein levels and lymphocytic pleocytosis. There was no evidence for accumulation of NIVO/IPI in the CSF. CONCLUSION Repeated intracavitary or intrathecal administration of NIVO +/- IPI in rGB is feasible and safe. Favourable survival outcome is seen in patients amenable to surgical resection.

C-reactive protein as a biomarker for immune-related adverse events in melanoma patients treated with immune checkpoint inhibitors in the adjuvant setting

The objective of this study was to evaluate the utility of serum C-reactive protein (CRP) as biomarker for the early diagnosis of immune-related adverse events (irAEs) in melanoma patients treated with immune checkpoint inhibitors (ICIs) in the adjuvant setting, and its potential correlation with relapse-free survival (RFS). Prospectively collected data from 72 melanoma patients treated with adjuvant ICIs were pooled. CRP values at diagnosis of 10 irAEs were descriptively analysed. Correlations between RFS and the occurrence of irAEs, the grade of the irAE, the extent of CRP-elevation and the use of corticosteroids for irAE treatment were investigated. A total of 191 irAEs (grade 1/2, n = 182; grade 3/4, n = 9) occurred in 64 patients [skin toxicity (n = 70), fatigue (n = 50), thyroiditis (n = 12), musculoskeletal toxicity (n = 11), sicca syndrome (n = 10), other (n = 23), pneumonitis (n = 6), colitis (n = 4), hepatitis (n = 3) and hypophysitis (n = 2)]. In pneumonitis and hypophysitis, the median CRP levels at diagnosis exceeded the upper limit of normal (ULN, 5 mg/L). After a median follow-up of 26.5 months, 28 patients (39%) had been diagnosed with a melanoma relapse. Patients who experienced no irAE were at the highest risk for relapse (P = 0.008). A trend was observed for patients diagnosed with an irAE that was associated with an elevated CRP (>2xULN) to be at higher risk for relapse as compared to those diagnosed with an irAE and CRP Collapse

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MESH Headings

• Biomarkers, Tumor/metabolism
• C-Reactive Protein/metabolism
• Female
• Humans
• Immune Checkpoint Inhibitors/adverse effects
• Immune Checkpoint Inhibitors/pharmacology
• Male
• Melanoma/complications
• Melanoma/drug therapy
• Melanoma/pathology
• Skin Neoplasms/complications
• Skin Neoplasms/drug therapy
• Skin Neoplasms/pathology

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Grants Collapse

Affiliation(s)

Justine Lauwyck UZ Brussel
Aline Beckwée Vrije Universiteit Brussel, Brussels Health Campus, Jette, Belgium
Arno Santens Vrije Universiteit Brussel, Brussels Health Campus, Jette, Belgium
Julia Katharina Schwarze UZ Brussel
Gil Awada UZ Brussel
Valérie Vandersleyen UZ Brussel
Sandrine Aspeslagh UZ Brussel
Bart Neyns UZ Brussel

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Intracerebral administration of CTLA-4 and PD-1 immune checkpoint blocking monoclonal antibodies in patients with recurrent glioblastoma: a phase I clinical trial

Background

Patients with recurrent glioblastoma (rGB) have a poor prognosis with a median overall survival (OS) of 30–39 weeks in prospective clinical trials. Intravenous administration of programmed cell death protein 1 and cytotoxic T-lymphocyte-associated antigen 4 inhibitors has low activity in patients with rGB. In this phase I clinical trial, intracerebral (IC) administration of ipilimumab (IPI) and nivolumab (NIVO) in combination with intravenous administration of NIVO was investigated.

Methods

Within 24 hours following the intravenous administration of a fixed dose (10 mg) of NIVO, patients underwent a maximal safe resection, followed by injection of IPI (10 mg; cohort-1), or IPI (5 mg) plus NIVO (10 mg; cohort-2) in the brain tissue lining the resection cavity. Intravenous administration of NIVO (10 mg) was repeated every 2 weeks (max. five administrations). Next generation sequencing and RNA gene expression profiling was performed on resected tumor tissue.

Results

Twenty-seven patients were enrolled (cohort-1: n=3; cohort-2: n=24). All patients underwent maximal safe resection and planned IC administrations and preoperative NIVO. Thirteen patients (cohort-1: n=3; cohort-2: n=10) received all five postoperative intravenous doses of NIVO. In cohort-2, 14 patients received a median of 3 (range 1–4) intravenous doses. Subacute postoperative neurological deterioration (n=2) was reversible on steroid treatment; no other central nervous system toxicity was observed. Immune-related adverse events were infrequent and mild. GB recurrence was diagnosed in 26 patients (median progression-free survival (PFS) is 11.7 weeks (range 2–152)); 21 patients have died due to progression. Median OS is 38 weeks (95% CI: 27 to 49) with a 6-month, 1-year, and 2-year OS-rate of, respectively, 74.1% (95% CI: 57 to 90), 40.7% (95% CI: 22 to 59), and 27% (95% CI: 9 to 44). OS compares favorable against a historical cohort (descriptive Log-Rank p>0.003). No significant difference was found with respect to PFS (descriptive Log-Rank test p>0.05). A higher tumor mRNA expression level of B7-H3 was associated with a significantly worse survival (multivariate Cox logistic regression, p>0.029).

Conclusion

IC administration of NIVO and IPI following maximal safe resection of rGB was feasible, safe, and associated with encouraging OS.

Trial registration

NCT03233152.

Acute exudative polymorphous vitelliform maculopathy during pembrolizumab treatment for metastatic melanoma: a case report

Background

The use of immunomodulating therapy to treat various cancers has been on the rise and these immune checkpoint inhibitors are known to cause ocular side effects. In this article a case of acute exudative polymorphous vitelliform maculopathy (AEPVM) is reported which developed during a first line treatment with pembrolizumab.

Case presentation

A 54-year-old woman was referred because of blurry vision in both eyes with a yellow spot in the central visual field of the left eye. These symptoms started after four treatments with pembrolizumab (a monoclonal antibody against the programmed cell death receptor-1) for a metastatic recurrent vaginal mucosal melanoma. Her best corrected visual acuity was 10/10 in both eyes with a correction of + 2.00 bilaterally. There were no inflammatory findings in the anterior segment or the vitreous. Fundoscopy revealed an attenuation of the foveal reflex with subtle yellow-white subretinal macular deposits (vitelliform lesions) in both eyes. Fluorescein angiography did not show staining or leakage in the mid-phase, neither a late staining. Spectral-domain optical coherence tomography of the macula illustrated bilateral neurosensory retinal detachment with a thick, highly reflective band at the outer photoreceptor segment. En face structural OCT at the level of the photoreceptors showed focal areas of increased signal corresponding to hyperreflective vitelliform material. The treatment with pembrolizumab was ceased immediately. During the following visits we slowly saw an improvement of the neurosensory retinal detachment. After almost four months a total resolution of the subretinal fluid was visualized in both eyes without the use of additional treatment, though the vitelliform deposits persisted.

Conclusions

The development of AEPVM in melanoma patients could be triggered by treatment with Pembrolizumab. Pembrolizumab has the potential to disturb indirectly the retinal pigment epithelium homeostasis with accumulation of lipofuscin deposits and subretinal fluid, both signs of AEPVM.

A phase 2 clinical trial on trametinib and low-dose dabrafenib in advanced pretreated BRAFV600/NRASQ61R/K/L wild-type melanoma (TraMel-WT): Interim efficacy and safety results

9529

Background: The mitogen-activated protein kinase (MAPK) pathway can be activated by alternative driver mutations in BRAFV600/ NRASQ61R/K/L wild-type (wt) melanoma. MEK-inhibitor monotherapy has activity in BRAFV600/ NRASQ61R/K/L wt melanoma, but is associated with considerate skin toxicity. Skin toxicity associated with the MEK-inhibitor trametinib (T) can be effectively mitigated by adding a low dose (50 mg BID) of the BRAF-inhibitor dabrafenib (LD-D) (Awada et al. Ann Oncol 2020). Methods: This two-stage, single-center phase 2 trial investigated T 2 mg QD in patients (pts) with advanced BRAFV600/ NRASQ61R/K/L wt melanoma who previously progressed on treatment with checkpoint inhibitors. In case of dose-limiting T-related skin toxicity, LD-D (50 mg BID) was added to T (pre-amend). The trial was amended in June 2019 to administer T upfront with LD-D (post-amend). Objective response rate (ORR, by RECIST v1.1) served as the primary endpoint. A Simon’s two-stage optimal design was used (p0 0.10; p1 0.30; alpha 0.05; power 0.80): in case of > 1 OR in the first 10 pts, 19 additional pts would be included in stage 2. The trial is considered positive if > 5 OR are observed. Results: As of February 9, 2021, 16 pts (3 pre-amend; 13 post-amend) were included (median age 56.5; male 56.3%; stage IIIB 6.3%, IV-M1a-c 68.8%, IV-M1d 25.0%; ECOG performance status 0-1 93.8%; normal lactate dehydrogenase 56.3%). Median duration of follow-up is 17.9 weeks (wks; range 1.9-90.1). The ORR in 14 evaluable pts is 42.9% (5 confirmed and 1 unconfirmed partial response), the disease control rate is 71.4%. Four OR are ongoing after a median follow-up of 8.0 wks (range 0.0-77.0), 2 responding pts progressed on therapy after respectively 16.6 and 24.0 wks. Four out of 6 OR are observed in pts with MAPK-pathway activating mutations (3 class II BRAF and 1 GNAQ mutation). Eight pts (50.0%) have progressed (median progression-free survival 16.4 wks [95% confidence interval [CI] 6.9-25.9]); 4 pts (25.0%) have died (median overall survival 54.7 wks [95% CI 37.6-71.8]). Adverse events (AE) are observed in all pts (grade [G] 3-4 9 [56.3%]). Two pre-amend pts added on LD-D due to dose-limiting T-related skin toxicity; no clinically relevant T-related skin toxicity was observed post-amend with the upfront addition of LD-D. The most frequent AE were creatine kinase increase (G1-2 11 [68.8%]; G3-4 1 [6.3%]), and anemia and acneiform rash (both G1-2 7 [43.8%]; G3-4 0). Therapy was temporarily interrupted due to AE in 11 pts (68.8%) and permanently interrupted in 1 pt (6.3%) due to recurrent pneumonitis. Conclusions: In this two-stage phase 2 trial, T plus LD-D was found to have promising antitumor activity and acceptable toxicity in pts with advanced pretreated BRAFV600/ NRASQ61R/K/L wt melanoma, especially in the presence of identifiable somatic MAPK-pathway activating mutations. Clinical trial information: NCT04059224.

A Phase 2 Clinical Trial of Trametinib and Low-Dose Dabrafenib in Patients with Advanced Pretreated NRASQ61R/K/L Mutant Melanoma (TraMel-WT)

BACKGROUND

MEK-inhibitor monotherapy has activity in advanced NRAS^Q61R/K/L mutant melanoma but is associated with dose-limiting cutaneous toxicity. The combination of a BRAF- with a MEK-inhibitor at their full dose (as in BRAF^V600E/K mutant melanoma) has low cutaneous toxicity. It is unknown whether a low dose of BRAF-inhibitor can mitigate the skin toxicity associated with full-dose MEK-inhibitor treatment in patients with advanced NRAS^Q61R/K/L mutant melanoma.

METHODS

This two-stage phase 2 clinical trial investigated trametinib 2 mg once daily in patients with advanced NRAS^Q61R/K/L mutant melanoma who were pretreated with immune checkpoint inhibitors. In case of trametinib-related cutaneous toxicity, low-dose dabrafenib (50 mg twice daily) was added to prevent recurrent cutaneous toxicity (pre-amendment). Following an amendment, trametinib was combined upfront with low-dose dabrafenib (post-amendment). Objective response rate (ORR) served as the primary endpoint.

RESULTS

All 6 patients enrolled pre-amendment developed trametinib-related cutaneous toxicity, necessitating treatment interruption. Combining trametinib with low-dose dabrafenib prevented recurrent skin toxicity thereafter. Trametinib-related skin toxicity was effectively mitigated in all 10 patients post-amendment. In all 16 included patients, the ORR and disease control rate was 6.3% (1 partial response) and 50.0%, respectively. The trial was halted after the first stage.

CONCLUSIONS

Combining full-dose trametinib with low-dose dabrafenib can mitigate MEK-inhibitor-related skin toxicity but was insufficiently active in this patient population. This combination can be of further interest for the treatment of MEK-inhibitor-sensitive tumors.

Choriocapillaris Assessment In Patients Under Mek-Inhibitor Therapy For Cutaneous Melanoma: An Optical Coherence Tomography Angiography Study

PURPOSE

The present study investigates by optical coherence tomography angiography (OCTA) the retinal capillary plexus and choriocapillaris flow voids and their possible correlation with MEKAR.

METHODS

34 eyes of 17 patients (61.5 years [30.4-77.4]) with stage IV cutaneous melanoma were included prospectively. All patients showed disease progression under treatment with Nivolumab/Ipilimumab and were subsequently treated with the MEK-inhibitor Trametinib 2 mg once daily. At the start and every 6 weeks during follow-up of 4 months, patients underwent a complete ophthalmologic exam, OCTA and when needed fluorescein angiography.

RESULTS

Statistical analysis was performed on 17 eyes of 9 patients. Eight patients were excluded due to missing OCTA images or due to drop-out because of decease or change of treatment. Comparing vessel area density (P = .625 and 0.681, respectively), vessel skeleton density (P = .996 and 0.766, respectively) of the superficial and deep capillary plexus, flow void number and total flow void area (mm² and %) (P = .495; 0.197 and 0.298, respectively) of choriocapillaris slab, before and after treatment, revealed no significant difference. The evolution of choriocapillaris flow void parameter did not significantly differ in patients, who developed MEKAR compared to patients who did not.

CONCLUSION

In patients receiving MEK-inhibitor with and without MEKAR, no significant different characteristics of the retinal capillary plexus and choriocapillaris were found. These data suggest that the development of MEKAR, has no correlation with vascular alteration.

A Comprehensive Analysis of Baseline Clinical Characteristics and Biomarkers Associated with Outcome in Advanced Melanoma Patients Treated with Pembrolizumab

Simple Summary

Pembrolizumab, a monoclonal antibody targeting programmed cell death 1, improves the survival of patients with advanced melanoma. This study aimed to investigate the association of baseline clinical characteristics, laboratory and imaging variables, and gene expression profiling scores on tumor tissue analysis of advanced melanoma patients who were treated with pembrolizumab, with survival using univariate and multivariate analysis. Baseline organ function (reflected by the presence of active brain metastases, number of metastatically affected organs, albumin) and systemic inflammatory/immunologic status (reflected by albumin, C-reactive protein, absolute lymphocyte count, neutrophil-to-lymphocyte ratio) are the most important clinical and/or laboratory parameters predictive of survival. Novel biomarkers include the baseline presence of BRAF^V600 or NRAS^Q61/G12/G13 mutant circulating tumor DNA and baseline total metabolic tumor volume assessed by whole-body ¹⁸F-FDG-PET/CT. Gene expression profiling scores by the NanoString PanCancer IO360 panel were not conclusive in our patient population.

Abstract

Background: Pembrolizumab improves the survival of patients with advanced melanoma. A comprehensive analysis of baseline variables that predict the benefit of pembrolizumab monotherapy has not been conducted. Methods: Survival data of patients with advanced melanoma who were treated with pembrolizumab in a single university hospital were collected. A multivariate Cox regression analysis was performed to correlate baseline clinical, laboratory, and radiologic characteristics and NanoString IO360 gene expression profiling (GEP) with survival. Results: 183 patients were included (stage IV 85.2%, WHO performance status ≥1 31.1%; pembrolizumab first-line 25.7%), of whom 112 underwent baseline ¹⁸F-FDG-PET/CT imaging, 58 had circulating tumor DNA (ctDNA) assessments, and GEP was available in 27 patients. Active brain metastases, a higher number of metastatic sites, lower albumin and absolute lymphocyte count (ALC), higher C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio, higher total metabolic tumor volume (TMTV), and higher ctDNA levels were associated with worse survival. Elevated lactate dehydrogenase (LDH) ≥ 2ULN (upper limit of normal), CRP ≥ 10ULN, or ALC < 750/mm³ delineate a subpopulation where treatment with pembrolizumab is futile. A TMTV ≥ 80 mL encompassed 17/21 patients with LDH ≥ 2ULN, CRP ≥ 10ULN, or ALC < 750/mm³. No significant associations were observed between baseline GEP scores and survival. Conclusion: Multiple baseline variables correlate with survival on pembrolizumab. TMTV is a more comprehensive baseline biomarker than CRP, LDH, or ALC in predicting the futility of pembrolizumab.

Immune checkpoint inhibitor therapy for ACTH-secreting pituitary carcinoma: a new emerging treatment?

BACKGROUND

Pituitary carcinomas are rare but aggressive and require maximally coordinated multimodal therapies. For refractory tumors, unresponsive to temozolomide (TMZ), therapeutic options are limited. Immune checkpoint inhibitors (ICI) may be considered for treatment as illustrated in the present case report.

CASE

We report a patient with ACTH-secreting pituitary carcinoma, progressive after multiple lines of therapy including chemotherapy with TMZ, who demonstrated disease stabilization by a combination of ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) ICI therapy.

DISCUSSION

Management of pituitary carcinoma beyond TMZ remains ill-defined and relies on case reports. TMZ creates, due to hypermutation, more immunogenic tumors and subsequently potential candidates for ICI therapy. This case report adds support to the possible role of ICI in the treatment of pituitary carcinoma.

CONCLUSION

ICI therapy could be a promising treatment option for pituitary carcinoma, considering the mechanisms of TMZ-induced hypermutation with increased immunogenicity, pituitary expression of CTLA-4 and PD-L1, and the frequent occurrence of hypophysitis as a side effect of ICI therapy.

Intratumoral Combinatorial Administration of CD1c (BDCA-1)+ Myeloid Dendritic Cells Plus Ipilimumab and Avelumab in Combination with Intravenous Low-Dose Nivolumab in Patients with Advanced Solid Tumors: A Phase IB Clinical Trial

Intratumoral (IT) myeloid dendritic cells (myDCs) play a pivotal role in re-licensing antitumor cytotoxic T lymphocytes. IT injection of the IgG₁ monoclonal antibodies ipilimumab and avelumab may induce antibody-dependent cellular cytotoxicity, thereby enhancing the release of tumor antigens that can be captured and processed by CD1c (BDCA-1)⁺ myDCs. Patients with advanced solid tumors after standard care were eligible for IT injections of ≥1 lesion with ipilimumab (10 mg) and avelumab (40 mg) and intravenous (IV) nivolumab (10 mg) on day 1, followed by IT injection of autologous CD1c (BDCA-1)⁺ myDCs on day 2. IT/IV administration of ipilimumab, avelumab, and nivolumab was repeated bi-weekly. Primary objectives were safety and feasibility. Nine patients were treated with a median of 21 × 10⁶ CD1c (BDCA-1)⁺ myDCs, and a median of 4 IT/IV administrations of ipilimumab, avelumab, and nivolumab. The treatment was safe with mainly injection-site reactions, but also immune-related pneumonitis (n = 2), colitis (n = 1), and bullous pemphigoid (n = 1). The best response was a durable partial response in a patient with stage IV melanoma who previously progressed on checkpoint inhibitors. Our combinatorial therapeutic approach, including IT injection of CD1c (BDCA-1)⁺ myDCs, is feasible and safe, and it resulted in encouraging signs of antitumor activity in patients with advanced solid tumors.

Axitinib plus avelumab in the treatment of recurrent glioblastoma: a stratified, open-label, single-center phase 2 clinical trial (GliAvAx)

BACKGROUND

No treatment demonstrated to improve survival in patients with recurrent glioblastoma (rGB) in a randomized trial. Combining axitinib with the programmed cell death ligand 1 blocking monoclonal antibody avelumab may result in synergistic activity against rGB.

METHODS

Adult patients with rGB following prior surgery, radiation therapy and temozolomide chemotherapy were stratified according to their baseline use of corticosteroids. Patients with a daily dose of ≤8 mg of methylprednisolone (or equivalent) initiated treatment with axitinib (5 mg oral two times per day) plus avelumab (10 mg/kg intravenous every 2 weeks) (Cohort-1). Patients with a higher baseline corticosteroid dose initiated axitinib monotherapy; avelumab was added after 6 weeks of therapy if the corticosteroid dose could be tapered to ≤8 mg of methylprednisolone (Cohort-2). Progression-free survival at 6 months (6-m-PFS%), per immunotherapy response assessment for neuro-oncology criteria, served as the primary endpoint.

RESULTS

Between June 2017 and August 2018, 54 patients (27 per cohort) were enrolled and initiated study treatment (median age: 55 years; 63% male; 91% Eastern Cooperative Oncology Group Performance Status 0-1). Seventeen (63%) patients treated in Cohort-2 received at least one dose of avelumab. The 6-m-PFS% was 22.2% (95% CI 6.5% to 37.9%) and 18.5% (95% CI 3.8% to 33.2%) in Cohort-1 and Cohort-2, respectively; median overall survival was 26.6 weeks (95% CI 20.8 to 32.4) in Cohort-1 and 18.0 weeks (95% CI 12.5 to 23.5) in Cohort-2. The best objective response rate was 33.3% and 22.2% in Cohort-1 and Cohort-2, respectively, with a median duration of response of 17.9 and 19.0 weeks. The most frequent treatment-related adverse events were dysphonia (67%), lymphopenia (50%), arterial hypertension and diarrhea (both 48%). There were no grade 5 adverse events.

CONCLUSION

The combination of avelumab plus axitinib has an acceptable toxicity profile but did not meet the prespecified threshold for activity justifying further investigation of this treatment in an unselected population of patients with rGB.

Durable Complete Response of a Recurrent Mesencephalic Glioblastoma Treated with Trametinib and Low-Dose Dabrafenib in a Patient with Neurofibromatosis Type 1

Patients with neurofibromatosis type 1 (NF1) have an increased lifetime risk for the development of nervous system tumors, including high-grade gliomas (glioblastoma). NF1 is associated with the loss of expression of neurofibromin 1 (NF1 gene product). This hyperactivates the mitogen-activated protein kinase pathway, leading to cellular proliferation and survival. MEK-inhibitor monotherapy is a promising treatment strategy in this setting, but is associated with distinct adverse events, most prominently cutaneous toxicity. We report the case of a young NF1 patient with a recurrent, heavily pretreated mesencephalic glioblastoma who was treated with the MEK-inhibitor trametinib (2 mg once daily). A partial response was documented, but unfortunately, he developed dose-limiting cutaneous toxicity (rash, paronychia). Based on interim results of a phase 2 trial in advanced BRAF^V600 wild-type melanoma indicating that a low dose of the BRAF-inhibitor dabrafenib is able to counter trametinib-related cutaneous toxicity, dabrafenib 50 mg twice daily was added. The cutaneous adverse events gradually recovered after addition of dabrafenib to trametinib. The patient eventually achieved a durable complete response, has excellent tolerance of his treatment and remains fully active.

Baseline biomarkers correlated with outcome in advanced melanoma treated with pembrolizumab monotherapy

e22041

Background: Pembrolizumab (PEMBRO) improves survival in advanced melanoma (MEL). This research investigates baseline (BL) biomarkers that predict long-term benefit on PEMBRO monotherapy. Methods: Outcome data on patients (pts) with advanced cutaneous/mucosal MEL treated with PEMBRO in our institution were collected after pt consent. Responses were evaluated using the immune-related response criteria. Total metabolic tumor volume (TMTV), assessed by 18-fluorodeoxyglucose positron emission tomography/computed tomography, was calculated as the sum of all tumor-associated voxels with a standardized uptake value (SUV) above the mean SUV measured in a reference region in normal liver tissue plus 3 standard deviations using Syngo.via software (Siemens Healthcare). The NanoString PanCancer IO360 panel was used for gene expression profiling (GEP). Results: A total of 196 pts was included in this analysis (median age 60; cutaneous 86%, mucosal 3%, unknown primary 12%; stage III 14%, IV-M1a/b/c 60%, IV-M1d 26%; first-line 24%). Median progression-free survival (PFS) in the population was 20.4 w (95% CI 10.2-30.7); median overall survival (OS) was 143.6 w (95% CI NR-NR). BL WHO Performance Status (PS) > 0 (HR 1.63 [95% CI 1.13-2.37]), C-reactive protein (CRP) > ULN (HR 1.92 [95% CI 1.33-2.77]), absolute lymphocyte count (ALC) < 750/mm³ (HR 2.45 [95% CI 1.32-4.55]) and > 1 metastatic site (HR 1.84 [95% CI 1.23-2.77]) were associated (P≤0.01) with worse PFS in multivariate analysis (Cox regression); BL WHO PS > 0 (HR 2.77 [95% CI 1.82-4.24]), lactate dehydrogenase (LDH) > ULN (HR 1.80 [95% CI 1.16-2.79]) and > 1 metastatic site (HR 1.95 [95% CI 1.16-3.25]) were associated with worse OS (P≤0.011). BL TMTV data were available in 118 pts (60%): BL CRP > ULN (HR 1.83 [95% CI 1.13-2.96]), ALC < 750/mm³ (HR 2.49 [95% CI 1.02-6.08]), > 1 metastatic site (HR 1.71 [95% CI 1.04-2.82]) and BL corticosteroid use (HR 4.62 [95% CI 1.38-15.45]) were associated with worse PFS (P < 0.05). BL WHO PS > 0 (HR 2.82 [95% CI 1.57-5.08]), ALC < 750/mm³ (HR 2.62 [95% CI 1.06-6.51]), history of brain metastases (HR 2.59 [95% CI 1.37-4.91]) and TMTV > 80 mL (HR 3.56 [95% CI 1.82-6.95]) were all associated with worse OS (P≤0.038). GEP data on a representative BL tumor sample were available in 27 pts (14%). Higher apoptosis signature scores were associated with increased probability of OS (HR 0.45 [95% CI 0.33-0.73], P < 0.01). Conclusions: BL TMTV > 80 mL identifies a subgroup of advanced MEL pts with worse outcome on PEMBRO. Increased apoptosis gene signature scores in a subset of patients predict increased OS.

A phase I clinical trial on intratumoral and intracavitary administration of ipilimumab and nivolumab in patients with recurrent glioblastoma

2534

Background: Intravenous (IV) administration of ipilimumab (IPI) and nivolumab (NIVO) has low activity in recurrent glioblastoma (rGB). Intratumoral (IT) and intracavitary (IC) administration of IPI and NIVO is under evaluation in the GlITIpNi phase I clinical trial. Methods: Patients (pts) with resectable rGB were recruited to cohorts C1, C2 and C4; pts with non-resectable rGB were recruited in C3 (biopsy only). IT administration (brain tissue lining the resection cavity during surgery) of IPI (10 mg)(C1), or IPI (5 mg) plus NIVO (10 mg)(C2, C3 and C4), was followed by IC administration of NIVO at escalating doses of 1, 5 or 10 mg Q2w in both C3 and C4 (via an Ommaya reservoir). In all cohorts, pts received 10 mg NIVO IV Q2w (6x in C1/C2, and 12x in C3/C4). Corticosteroids were contraindicated. Results: Forty-six pts (31 male; median age 56y (38-74); IDH1 R132H mutation in 2 pts in C1/C2; NGS somatic mutation analysis for C3/C4 ongoing) with rGB following resection, RT and temozolomide were enrolled (3, 24, 13 and 6 pts in C1, C2, C3 and C4, respectively). All pts received IT administrations. Pts in C1/C2 received a median of 5 IV NIVO administrations. Study treatment has been completed in all pts in C1/C2, in 9 pts in C3, and in 3 pts in C4; pts received a median of 4 (0-10) and 3 (0-7) postoperative IC/IV administrations in C3 and C4, respectively. Two pts in C2 and 1 pt in C3 had an increased perilesional cerebral edema (G3) with neurological deterioration after surgery/IT-injection, that was reversible with steroids. Most frequent AE were fatigue (32 pts, 64%), fever (20 pts, 44%), and headache (25 pts, 50%). In 4 pts from C3, the Ommaya was removed because of bacterial colonization (asymptomatic). There were no G5 AE. There was no dose/AE correlation with increasing IC NIVO doses in C3/C4. Repetitive CSV analysis during therapy (C3/C4) revealed increased lymphocyte counts in 4 pts; scRNA- and TCR-sequencing is ongoing. Gene expression profiling for C1/C2, and pharmacokinetic analysis of NIVO and IPI in CSV for C3/C4 are ongoing. After a median FU of 62w (16-165) for pts in C1/C2, 16 pts have died; median OS is 71w (95% CI 8-134), 1- and 2y-OS% are respectively 51% (95% CI 31-71), and 34% (95% CI 10-59). OS compares favorably to a historical cohort of Belgian rGB pts (n = 469; Log-Rank p .001). After a median FU of 10w (1-37) for pts in C3/C4, 2 pts have died; median OS has not been reached. One pt in C3 achieved a PR that is ongoing at 12m. Conclusions: IT/IC administration of NIVO and IPI is feasible and sufficiently safe to warrant further investigation in pts with rGB. Clinical trial information: NCT03233152 .

SUN-923 Combination Immune Checkpoint Inhibitor Therapy for ACTH-Secreting Pituitary Carcinoma

Introduction

Pituitary carcinoma is a rare yet serious entity with poor prognosis despite multimodal therapies. Cerebrospinal and/or systemic metastases are present by definition, making adjuvant systemic therapy necessary. Novel treatments are urgently needed for refractory cases. Immunotherapy with immune checkpoint inhibitors (ICI) targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed cell death 1 (PD-1) or its ligand (PD-L1) has been a revolution in multiple malignancies. The expression of CTLA-4 and PD-L1 has been elucidated in pituitary adenomas and could be implicated in pituitary carcinomas as well. Hypophysitis is also a frequent endocrine immune-related adverse event, especially during CTLA-4 blockade (with ipilimumab) or combination ICI. However, the efficacy of ICI in the treatment of refractory pituitary tumors has yet to be established. In 2018, Lin et al. successfully treated a first case of a hypermutated aggressive ACTH-secreting pituitary carcinoma with ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) combination immunotherapy.

Clinical Case

We report a 40-year old male, diagnosed with an invasive ACTH-secreting pituitary macroadenoma in 2012, initially treated by transsphenoidal and transcranial surgery, followed by adjuvant stereotactic radiotherapy and several courses of ketoconazole. In 2017, he presented to our clinic for a recurrent Cushing’s phenotype despite maximal dosing of ketoconazole. Therapy both with pasireotide and cabergoline was unable to normalize cortisol levels and a bilateral (subtotal) adrenalectomy was performed. In June 2018, he presented to our emergency department with acute diplopia due to a left abducens nerve palsy. Imaging revealed recurrent invasion of the tumor into the sella turcica and cavernous sinus, together with cerebellar and drop metastases at the cervical spine. Temozolomide (TMZ) was initiated for a total of 9 cycles. Progressive disease was observed with development of new onset right oculomotor nerve palsy after the last TMZ cycle, and persistence of elevated serum ACTH-cortisol and urinary cortisol levels, despite the absence of radiological progression. Therefore, he was started in a compassionate use setting with a combination ICI therapy with ipilimumab 3 mg/kg and nivolumab 1 mg/kg (for 4 cycles), followed by maintenance nivolumab therapy (240 mg) every two weeks. He has stable disease (both radiographically and hormonally) five months after the initiation of the immunotherapy.

Clinical Lesson(s) or Conclusion(s)

We report the second case of ACTH-secreting pituitary carcinoma treated with combination ICI therapy. The disease status of the patient is stable up until now, suggesting at least disease control by the immunotherapy. Checkpoint blockade inhibitors are a promising novel treatment modality for refractory pituitary tumors and should be further studied.

SCIDOT-30. GLITIPNI: A PHASE 1B CLINICAL TRIAL COMBINING SURGICAL RESECTION WITH DIRECT INTRACEREBRAL INJECTION OF IMMUNE CHECKPOINT INHIBITORS IN PATIENTS WITH RECURRENT GLIOBLASTOMA

INTRODUCTION

Intravenous (iv) administration of PD-1 blocking mAb is largely ineffective for the treatment of recurrent glioblastoma (rGB). Combination of iv-ipilimumab (IPI) plus nivolumab (NIVO) is associated with a high incidence of irAE. Intracerebral (ic) administration of immune-checkpoint inhibiting mAb following the resection of rGB could be a more effective and safer alternative to iv-dosing.

METHODS

Patients underwent maximal safe resection of their rGB followed by ic-injection of 10mg IPI (cohort-1) or 5mg IPI plus 10mg NIVO (cohort-2) in the wall of the resection cavity. In both cohorts 10mg nivolumab was administered iv for a max of 6 doses, starting 1 day pre-operatively.

RESULTS

21 pts were included (3 in C-1, 18 in C-2; 8F/13M; median age 56y [range 38–72]; 17 de novo GB, 4 secGB). All patients underwent maximal safe surgical resection followed by ic-injection of IPI and NIVO as planned. Median number of iv-administrations of NIVO was 5 (range 1–8). Treatment was generally well tolerated. Postoperatively, 2 patients experienced a G3 symptomatic increase in perilesional cerebral edema with neurological deterioration, reversible upon steroid treatment. One patient had worsening neurological symptoms related to an inflammatory intracerebral cyst at the resection site, requiring surgical decompression 4 months post-study treatment. Most frequent AEs were fatigue (2pts G3, 8pts G2), postoperative fever (11pts G1) and headache (3pts G2); 1pt developed G3 pneumonitis. No other immune-related AEs or treatment-related deaths occurred. After median follow-up of 60 weeks, median PFS is 14.4 weeks (95% CI 11.2–17.6); 11/21 patients are alive, and 1- and 2y-OS% are respectively 46% (95% CI 19- 73%), and15% (95% CI 0–42%).

CONCLUSION

This is the first study demonstrating the safety and activity of combined surgical resection of rGB with local intracerebral administration of immune checkpoint-inhibiting mAb. Survival compares favorably to historical controls justifying further investigation of this experimental therapy.

ATIM-38. GLITIPNI: A PHASE 1B CLINICAL TRIAL COMBINING SURGICAL RESECTION WITH DIRECT INTRACEREBRAL INJECTION OF IMMUNE CHECKPOINT INHIBITORS IN PATIENTS WITH RECURRENT GLIOBLASTOMA

INTRODUCTION

Intravenous (iv) administration of PD-1 blocking mAb is largely ineffective for the treatment of recurrent glioblastoma (rGB). Combination of iv-ipilimumab (IPI) plus nivolumab (NIVO) is associated with a high incidence of irAE. Intracerebral (ic) administration of immune-checkpoint inhibiting mAb following the resection of rGB could be a more effective and safer alternative to iv-dosing.

METHODS

Patients underwent maximal safe resection of their rGB followed by ic-injection of 10mg IPI (cohort-1) or 5mg IPI plus 10mg NIVO (cohort-2) in the wall of the resection cavity. In both cohorts 10mg nivolumab was administered iv for a max of 6 doses, starting 1 day pre-operatively.

RESULTS

21 pts were included (3 in C-1, 18 in C-2; 8F/13M; median age 56y [range 38–72]; 17 de novo GB, 4 secGB). All patients underwent maximal safe surgical resection followed by ic-injection of IPI and NIVO as planned. Median number of iv-administrations of NIVO was 5 (range 1–8). Treatment was generally well tolerated. Postoperatively, 2 patients experienced a G3 symptomatic increase in perilesional cerebral edema with neurological deterioration, reversible upon steroid treatment. One patient had worsening neurological symptoms related to an inflammatory intracerebral cyst at the resection site, requiring surgical decompression 4 months post-study treatment. Most frequent AEs were fatigue (2pts G3, 8pts G2), postoperative fever (11pts G1) and headache (3pts G2); 1pt developed G3 pneumonitis. No other immune-related AEs or treatment-related deaths occurred. After median follow-up of 60 weeks, median PFS is 14.4 weeks (95% CI 11.2–17.6); 11/21 patients are alive, and 1- and 2y-OS% are respectively 46% (95% CI 19- 73%), and15% (95% CI 0–42%).

CONCLUSION

This is the first study demonstrating the safety and activity of combined surgical resection of rGB with local intracerebral administration of immune checkpoint-inhibiting mAb. Survival compares favorably to historical controls justifying further investigation of this experimental therapy.

Undetectable circulating tumor DNA (ctDNA) levels correlate with favorable outcome in metastatic melanoma patients treated with anti-PD1 therapy

BACKGROUND

Treatment with anti-PD1 monoclonal antibodies improves the survival of metastatic melanoma patients but only a subgroup of patients benefits from durable disease control. Predictive biomarkers for durable benefit could improve the clinical management of patients.

METHODS

Plasma samples were collected from patients receiving anti-PD1 therapy for ctDNA quantitative assessment of BRAFV600 and NRASQ61/G12/G13 mutations.

RESULTS

After a median follow-up of 84 weeks 457 samples from 85 patients were analyzed. Patients with undetectable ctDNA at baseline had a better PFS (Hazard ratio (HR) = 0.47, median 26 weeks versus 9 weeks, p = 0.01) and OS (HR = 0.37, median not reached versus 21.3 weeks, p = 0.005) than patients with detectable ctDNA. Additionally, the HR for death was lower after the ctDNA level became undetectable during follow-up (adjusted HR: 0.16 (95% CI 0.07-0.36), p-value < 0.001). ctDNA levels > 500 copies/ml at baseline or week 3 were associated with poor clinical outcome. Patients progressive exclusively in the central nervous system (CNS) had undetectable ctDNA at baseline and at subsequent assessments. In multivariate analysis adjusted for LDH, CRP, ECOG and number of metastatic sites, the ctDNA remained significant for PFS and OS. A positive correlation was observed between ctDNA levels and total metabolic tumor volume (TMTV), number of metastatic sites and total tumor burden.

CONCLUSIONS

Assessment of ctDNA baseline and during therapy was predictive for tumor response and clinical outcome in metastatic melanoma patients and reflected the tumor burden. ctDNA evaluation provided reliable complementary information during anti-PD1 antibody therapy.

A phase Ib clinical trial on intratumoral administration of autologous CD1c (BDCA-1)+ myeloid dendritic cells (myDC) in combination with ipilimumab (IPI) and avelumab (AVE) plus intravenous low-dose nivolumab (NIVO) in patients with advanced solid tumors

e14012

Background: Intratumoral (IT) myDC play a pivotal role in initiating antitumor immune responses and "re-licensing” of antitumor cytotoxic T-lymphocytes within the tumor microenvironment. IT injection of anti-PD-L1 IgG1 mAb AVE and anti-CTLA-4 IgG1 mAb IPI may reduce the number of regulatory T cells and lyse PD-L1+ tumor cells, thereby releasing tumor antigens that can be captured and processed by IT co-administered CD1c (BDCA-1)+ myDC, reinvigorating the cancer immunity cycle. Methods: Patients (pts) with advanced solid tumors who failed standard therapy were eligible for IT injections of ≥1 non-visceral metastasis with IPI (max total dose of 10 mg) and AVE (max total dose of 40 mg) plus IV NIVO (10 mg) on day 1 followed by IT injection of autologous, non-substantially manipulated CD1c (BDCA-1)+ myDC on day 2. Administration of AVE, IPI, and NIVO was repeated every 14 days thereafter. Primary endpoints were safety and feasibility. Repetitive FNA cytology/IHC of treated lesions was performed. Results: In this ongoing trial, 6 pts (3x melanoma, 1x epithelial ovarian carcinoma, 2x triple negative breast carcinoma) were treated with IT injection of a median of 27,2x106 (range 10-43x106) CD1c (BDCA-1)+ myDC and a median of 5 (range 2-10) study drug administrations. At time of this analysis 3 pts are evaluable for response: an ongoing PR ( > 8 months) was documented in a melanoma pt who previously progressed on PD-1 and CTLA-4 inhibitors. In 2 other melanoma pts regression of the injected metastases coincided with progression of non-injected metastases. Adverse events consisted of transient grade(G)2 local pain at injection site in 2 pts, G1 pruritus in 2 pts, G2 pneumonitis in 1 pt, G1 rash in 1 pt, and pruritus and redness of the skin overlaying the injected lesion in 1 pt. Analysis of cytology/IHC results is ongoing. Conclusions: IT injection of autologous CD1c (BDCA-1)+ myDC with IT co-injection of AVE and IPI plus IV low-dose NIVO is feasible and tolerable and resulted in encouraging early signs of anti-tumor activity in injected as well as non-injected lesions. Clinical trial information: NCT03707808.

A sequential dual cohort phase II clinical trial on adjuvant low-dose nivolumab with or without low-dose ipilimumab as adjuvant therapy following the resection of melanoma macrometastases (MM)

9585

Background: Optimal dosing and duration of adjuvant treatment with anti-PD-1 checkpoint inhibitors, e.g. nivolumab (NIVO), following complete resection of melanoma (MEL) lymph node metastases has not been established. We investigated a regimen of low-dose NIVO with/without low-dose ipilimumab (IPI) as adjuvant therapy in MEL pts. Methods: After complete resection of MM, pts were treated with IPI 50mg (fixed dose, 1x) plus NIVO 10mg (fixed dose, Q2w x4) (Cohort-A), or NIVO 10mg (Q2w x9, Q8w x4) (Cohort-B). One-year relapse-free survival (RFS) rate served as primary endpoint. Sample size (34 pts) was calculated according to a Fleming one-stage clinical trial design. Recruitment to Cohort-B was closed prematurely following registration of NIVO in the adjuvant setting by EMA. Secondary endpoints were safety, distant metastasis-free survival (DMFS) and overall survival (OS). Quantitative measurement of BRAF/ NRAS mutant circulating tumor DNA (ctDNA), as well as tumor gene expression profiling were performed. Results: 34 pts (15M/19F, 31 stage III/3 stage IV) and 22 pts (12M/10F, 21 stage III/1 stage IV) were enrolled in Cohort-A/-B, respectively. After a median follow-up of 86w for Cohort-A and 36w for Cohort-B, estimated 12 months (m) RFS-rate was respectively 55% (95% CI, 39–72) and 78% (95% CI, 73-82), 12m OS-rate was 97% (95% CI, 94-100) and 100%, and 12m DMFS-rate was 79% (95% CI, 92-65), no distant metastases occurred in Cohort-B. Median RFS for Cohort-A was 84w (95%, CI 28-139), not-reached in -B. Median DMFS and OS had not been reached at time of analysis in either cohort. All grade treatment-related adverse events were observed in 21 (61%)/17 (77%) with 3 (8%)/1 (4%) grade 3 irAE in Cohort-A/-B, respectively. One patient in Cohort-A had a detectable level of ctDNA at baseline and relapsed 33w after initiating treatment. Tumor profiling is ongoing at time of submission. Conclusions: The investigated adjuvant low-dose regimens have an acceptable safety profile. Survival rates resemble those of standard regimens. These regimens could be economically advantageous alternatives for pts without access to standard regimens. Clinical trial information: NCT02941744.

GLIAVAX: A stratified phase II clinical trial of avelumab and axitinib in patients with recurrent glioblastoma

2034

Background: Patients (pts) with recurrent glioblastoma (rGB) have a poor prognosis, and no treatment option demonstrated to improve survival in a randomized trial. Axitinib (AXI), an oral VEGFR 1-3 inhibitor has demonstrated single agent activity in rGB and reduces the need for corticosteroids (CS). Avelumab (AVE) is a fully human anti-PD-L1 IgG1 antibody with clinical activity in various tumor types. Combination of AXI and AVE may improve the outcome of pts with rGB. Methods: This open-label, dual-strata, single-center phase 2 clinical trial investigated the activity of AXI plus AVE in adult pts with rGB following prior surgery, RT and temozolomide. Pts were stratified according to their baseline use of CS. Pts without baseline need for CS initiated treatment with AXI (5 mg oral BID) plus AVE (10 mg/kg IV Q2W) (cohort-1). Pts in need of CS initiated AXI as a monotherapy; AVE could be added to AXI after 6 wks if the CS dose could be tapered to a physiologic dose level or less (cohort-2). Six-month-PFS served as the primary endpoint (with a prespecified threshold of ≥ 50% for cohort-1) according to Fleming one-stage design. Results: Between Jun 2017 and Aug 2018, 54 pts (27 per cohort) were enrolled (med age 55 y [range 19-75]; 63% male; 91% WHO PS 0-1). All pts in cohort-1 and 16 pts (59%) in cohort-2 received at least 1 dose of AVE. The 6-month-PFS was 18% (95% CI 4-33) in both cohorts. At the time of analysis, 2 pts were progression-free and continuing study treatment. Median OS in cohort-1 and -2 was respectively 26 wks (95% CI 21-32) and 18 wks (95% CI 14-22). No clear relation was found between baseline cognitive functioning (Cogstate subtests) and PFS/OS. The best overall response rate (iRANO) was 41% and 26% respectively for pts in cohort-1 and -2. The most frequent all-grade treatment-related adverse events (TRAE) were dysphonia (67%), lymphopenia (50%), diarrhea (48%), hypertension (48%), and fatigue (46%). The incidence of grade 3-4 TRAE was 30%; there were no grade 5 AE. Conclusions: The combination of AVE plus AXI is sufficiently well tolerated but did not meet the threshold for activity justifying further investigation in an unselected population of patients with rGB. Clinical trial information: NCT03291314.

Emotional and cognitive disturbances in long-term melanoma survivors treated with ipilimumab

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Background: Immunotherapy with the CTLA-4 blocking mAb ipilimumab (IPI) has improved the long-term (>3 y) survival of a subpopulation (15-20%) of patients (pts) with metastatic melanoma. Little is known about the psychosocial outcome and the long-term effects of immune-related adverse events in these survivors. Methods: Pts with advanced melanoma (AJCC stages IIIC or IV) who were in complete remission for at least 2 y after treatment initiation, were eligible for this ongoing study. Data on health related quality of life (HRQOL), psychosocial outcome and neurocognitive function (NCF) were collected using 5 validated questionnaires, a semi-structured psychiatric examination (SSPE), and computer-based NCF testing. Results: Test results from 17 pts (5 F/12 M), median age 57 y (range 33-86) were analyzed. Median time since start of IPI was 5.5 y (range 2-7). Seven pts (41%) had elevated scores on the Cognitive Failure Questionnaire (CFQ). Nine pts (53%) had elevated scores on the Hospitalization Depression Scale (HADS) indicating moderate anxiety (4 pts), severe anxiety (2 pts), and moderate depression (3 pts). The SSPE revealed that all 10 pts who were professionally active at the time of diagnosis, had to change or stop work due to their illness. Nine pts (53%) reported persisting emotional distress: anxiety, existential problems, survivor guilt, post-traumatic stress symptoms or daily worrying about the disease. Three pts were referred for suicidal ideation in relation with their disease. Four pts (24%) developed hypophysitis and suffered from comorbid depression (1 pt), adjustment disorder (2 pt), or post-traumatic stress disorder related to the symptoms of hypopituitarism (1 pt). Five years after the incidence of hypophysitis, all pts had elevated scores on the Fatigue Severity Scale, the HADS; and 3 pts on the CFQ. All cases of skin toxicity (8 pts), hepatitis (2 pts), colitis (2 pts), sarcoidosis (2 pts), and Guillain-Barre syndrome (1 pt) resolved without long-term impact on HRQOL. Conclusions: A majority of melanoma survivors treated with IPI continues to suffer from emotional distress and cognitive problems impacting their HRQOL. Timely detection and providing adaptive care is imperative.

Pharmacologic measures in the prevention of left ventricular dysfunction associated with molecular-targeted therapies in the treatment of cancer patients

INTRODUCTION

Left ventricular dysfunction (LVD) is an infrequent but significant side effect of certain molecular-targeted cancer therapies and may lead to treatment modification and impact on disease prognosis. There may be a role for beta blockers (BB), angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) in the prevention of LVD. Areas covered: There are multiple definitions for LVD based on clinical and/or imaging features. Molecular-targeted therapies cause reversible LVD. Therapies with well-reported LVD are inhibitors of human epidermal growth factor 2 (HER2), angiogenesis, Abelson murine leukemia viral oncogene homolog (ABL) and the proteasome. BB, ACEI and ARB seem to have a role in the prevention of LVD associated with anthracyclines. Few trials have investigated the role of BB, ACEI and ARB as primary prevention of LVD in molecular-targeted therapies. Their results are not conclusive but a beneficial role cannot be excluded. Expert opinion: Because of inconclusive data, future interventional studies should not include all treated patients with molecular-targeted therapy, but focus on patients at risk for developing LVD. Another option is to study patients who show early signs of LVD to prevent progression to overt heart failure.

The second wave of immune checkpoint inhibitor tsunami: advance, challenges and perspectives

After the first wave of the tsunami of immune checkpoint inhibitors, 2016 was marked by the second wave, revealed by numerous US FDA approvals, publications and abstracts in relation with these drugs in different cancers and settings. First, we reported all new indications of anti-CTLA4, anti-programmed cell death protein 1 and anti-PDL1 approved by the FDA, the positive clinical trials published and the abstracts reported at important scientific meetings during 2016. Then, we highlighted the updates on debatable issues related to checkpoint inhibitors, since the first wave published in a previous issue. We focused on the predictive biomarkers, combination therapies, tumor response patterns and efficacy in particular settings and the side effect management. Finally, the impact of checkpoint inhibitors development on the care management of cancer centers will be discussed.

Checkpoint inhibitors in the treatment of brain metastases of non-small-cell lung cancer and melanoma

Brain metastases (BMs) are representing a new challenge for the oncologist; their incidence is increasing due to the better overall survival and systemic disease control in many malignancies, consequent to new potent cytotoxic and targeted therapies. In the era of immunotherapies, checkpoint inhibitors are representing a new therapeutic option in different solid tumors and settings; preliminary results showed potential activity of these agents in patients with BM, when administered as single agent or in combination with radiation therapy. After presenting the arguments in favor of this new strategy, we reported the preliminary results of the trials evaluating these agents in BM, we described the ongoing trials and we discussed the potential role of these agents in the BM treatment.

Emerging drugs targeting human epidermal growth factor receptor 2 (HER2) in the treatment of breast cancer

INTRODUCTION

Human epidermal growth factor 2 (HER2) overexpression is present in 20% of breast cancer patients. It is associated with more aggressive disease and worse clinical outcome. New drugs are thus needed. Approved and future treatments will be discussed in this review.

AREAS COVERED

The monoclonal antibodies trastuzumab and pertuzumab, the tyrosine kinase inhibitor lapatinib and the antibody-drug conjugate trastuzmab emtansine are approved for HER2 positive breast cancer. The combination of trastuzumab, pertuzumab and docetaxel is currently the first-line treatment in the metastatic setting. New therapies are still needed due to frequent relapse and resistance. These include mammalian target of rapamycin inhibitors, heat shock protein 90 inhibitors, pan-HER2 tyrosine kinase inhibitors, antibody-drug conjugates, immunotherapy agents (antibodies and vaccines), radioimmunotherapy and HER2 specific affinity proteins. Possible developmental issues are the complexity of the molecular biology of the HER2 positive cancer cell, the occurrence of resistance, toxicity and the high cost.

EXPERT OPINION

The determination of the right sequence of use of old and new therapies remains a challenging issue. The selection of patients who do or don't benefit from potentially toxic chemotherapy is also difficult. Central nervous system metastases are a common problem in HER2 positive breast cancer that needs to be addressed in future trials.

Novel mechanisms and approaches in the medical therapy of solid cancers

Major advances in cancer research in the last two decades have provided us with a better understanding of the dynamics of the cancer cell and its microenvironment. This has consequently led to the development of new therapies and treatment strategies either targeting the cancer cell or the tumor microenvironment. In this review we will discuss the major existing and promising future treatment approaches in medical oncology. Therapies targeting the cancer cell include hormonal therapies, small molecules, and monoclonal antibodies. They are used mostly in the advanced disease setting. Strategies developed more recently are antibody drug conjugates (trastuzumab emtansine and radioimmunotherapy) and oncolytic viruses. Molecular therapies targeting the tumor microenvironment include angiogenesis inhibitors and the new agents and approaches that interfere with the immune system (immune checkpoint inhibitors and adoptive cell therapy). The development of resistance (primary and acquired) to targeted therapies is unfortunately a common phenomenon that can be overcome or delayed using multiple strategies like the use of second- or third-generation molecular therapies targeting the emerging resistant mutations or genetic abnormalities, multitargeted drugs, and drug combinations targeting the same or different proteins, and/or the use of modern immunotherapy. Molecular targeted therapies have a distinct array of side effects that can be mechanism-based, but can also be unpredictable. Although the progress in research brings a vast amount of new information about cancer and its environment, it renders the field of oncologic research more and more complex with fragmentation of tumor entities. These are important challenges for future research and precision oncology.