Isatuximab plus atezolizumab in patients with advanced solid tumors: results from a phase I/II, open-label, multicenter study

BACKGROUND

The anti-CD38 antibody isatuximab is approved for the treatment of relapsed/refractory multiple myeloma, but there are no data on its efficacy in solid tumors. This phase I/II study (NCT03637764) assessed the safety and activity of isatuximab plus atezolizumab (Isa + Atezo), an anti-programmed death-ligand 1 (PD-L1) antibody, in patients with immunotherapy-naive solid tumors: epithelial ovarian cancer (EOC), glioblastoma (GBM), hepatocellular carcinoma (HCC), and squamous cell carcinoma of the head and neck (SCCHN).

PATIENTS AND METHODS

Phase I assessed safety, tolerability, pharmacokinetics, pharmacodynamics, and the recommended phase II dose (RP2D) of isatuximab 10 mg/kg intravenously (i.v.) every week for 3 weeks followed by once every 3 weeks + atezolizumab 1200 mg i.v. every 3 weeks. Phase II used a Simon's two-stage design to assess the overall response rate or progression-free survival rate at 6 months (GBM cohort). Interim analysis was carried out at 6 months following first dose of the last enrolled patient in each cohort. Pharmacodynamic biomarkers were tested for CD38, PD-L1, tumor-infiltrating immune cells, and FOXP3+ regulatory T cells (Tregs) in the tumor microenvironment (TME).

RESULTS

Overall, 107 patients were treated (EOC, n = 18; GBM, n = 33; HCC, n = 27; SCCHN, n = 29). In phase I, Isa + Atezo showed an acceptable safety profile, no dose-limiting toxicities were observed, and RP2D was confirmed. Most patients experienced ≥1 treatment-emergent adverse event (TEAE), with ≤48.5% being grade ≥3. The most frequent TEAE was infusion reactions. The study did not continue to stage 2 based on prespecified targets. Tumor-infiltrating CD38+ immune cells were reduced and almost cleared after treatment. Isa + Atezo did not significantly modulate Tregs or PD-L1 expression in the TME.

CONCLUSIONS

Isa + Atezo had acceptable safety and tolerability. Clinical pharmacodynamic evaluation revealed efficient target engagement of isatuximab via treatment-mediated reduction of CD38+ immune cells in the TME. Based on clinical data, CD38 inhibition does not improve responsiveness to PD-L1 blockade in these patients.

PL02.1.A EO2401, a novel microbiome-derived therapeutic vaccine for patients with recurrent glioblastoma: ROSALIE study

Background

EO2401 (EO) was designed to activate existing commensal memory T-cells cross-reacting with tumor associated antigens (TAAs). EO includes microbial-derived, synthetically produced peptides corresponding to HLA-A2 restricted epitopes with molecular mimicry to three TAAs upregulated in glioblastoma (GB), IL13Rα2, BIRC5 and FOXM1, with the CD4 helper peptide UCP2 and the adjuvant Montanide. Pre-clinically EO generated strong immune responses and cross-reactive CD8 cells recognizing the targeted TAAs.

Methods

This ongoing Ph 1/2 trial (NCT04116658) investigates the safety and tolerability (primary) of EO (300 µg/peptide, SC Q2W X 4, then Q4W), EO with nivolumab (3 mg/kg Q2W; EN), and EN with bevacizumab (10 mg/kg Q2W; ENB) among four Cohorts (Cs) of pts with GB at first progression/recurrence after radiotherapy/temozolomide. Treatment was delivered until progression, or 24 months. After the Ph 1 of EO followed by EN (C1), C2 investigated EN without (C2a) or with (C2b) surgery while C3 investigated ENB (population as C2a).

Results

Among 40 treated pts (C1 n=3, C2a n=23, C2b n=3, C3 n=11), median age was 60 years, 53% were male, 40% had KPS 90-100%, 35% had O6-methylguanine DNA-methyltransferase promotor hypermethylated tumors, and 5% isocitrate dehydrogenase 1 mutated tumors. All evaluable pts demonstrated strong CD8 T-cell ELISPOT responses against the 3 vaccine peptides; response was shown with tetramer staining of specific CD8 in 24/25 investigated pts after in vitro stimulation and in 19/20 pts directly ex vivo. Cross-reactivity against targeted TAAs was confirmed in 20/21 pts. Majority of response were detected by week 4 after 1st dose and as early as 2 weeks in some pts. EO, EN, and ENB were well tolerated (max exposure EN 86 wks, ENB 47 wks) with EO associated toxicity limited to local administration site reactions (48%; all grade 1-2). The frequency and severity of nivolumab- or bevacizumab-associated AEs was consistent with historical single-agent profiles. With a median follow-up of 13.6 months, median progression-free survival (mPFS), and median survival for EN (C1+C2a+C2b) were 1.8 months (2 ongoing at 7.3, and 18.5 months), and 11.0 months (survival at 12 months 42%), respectively. With a median follow-up of 7.3 months (range, 3.0-10.5), pts on ENB (C3) have mPFS and survival at 6 months of 5.5 months (3 ongoing at 5.6, 7.3 and 9.1 months), and 82% (9/11 alive), respectively. ORR/DCR (ORR+SD) for EN and ENB were 10%/34% and 55%/82%, respectively.

Conclusion

EO2401 generated strong systemic immune responses and was well tolerated in combination with nivolumab ± bevacizumab. Preliminary ORR/DCR and mPFS for ENB, and survival for EN seem encouraging. Updated results from the current 40 patients and results from additional 35 patients who already started treatment with EN with the option for low-dose bevacizumab edema treatment at neurological symptoms will be presented.

P14.58 Efficacy and safety of lomustine versus fotemustine as first and second line treament in relapsed glioblastoma patients

BACKGROUND

Glioblastoma (GB) is the most aggressive primary brain tumour. Despite the survival benefit associated with adjuvant therapy, most of patients (pts) relapse after initial therapy. Nitrosoureas (NU) are the standard treatment at relapse in Europe. Both fotemustine (FM) (Addeo schema) and lomustine (LM) (administered orally every 6 weeks) are used in this context.

MATERIAL AND METHODS

This retrospective cohort study included pts diagnosed with GB treated with NU at relapse in four Catalonia hospitals from 2010 to 2020. Clinical and pathological data were collected from medical records. We analysed 6months-progression-free survival (6m-PFS), progression-free survival (PFS) and overall survival (OS) from the start of NU to progression or death respectively. Differences in toxicity grade using CTCAE v5.0 were analysed globally as ‘non-toxicity’, ‘mild toxicity (grade 1 or 2)’ and ‘high toxicity (grade 3 or 4)’.

RESULTS

We identified 236 GB pts with a median age of 58 years old. 29% of the pts presented MGMT promotor methylation and only 3%(n=7) had IDH mutation. After a median follow-up of 20 months, 94% of the pts were dead at the time of the analyses. At first line, 83 pts were treated with FM and 18 with LM. Pts treated with FM had better performance status (PS) than those treated with LM (p=.010). Median PFS was 2 months and 6m-PFS was 12% vs 6% in FM and LM group respectively (p=.87). Median OS was 3 months with LM vs 6 months with FM, with no statistically significant differences even adjusted for prognostic factors (p=.79 HR:0.9 CI 95% 0.41–1.96).At second line, 78 were treated with FM and 24 with LM, no differences between groups. Median PFS was 2 months in both groups and median OS was 3 vs 5 months for pts treated with LM vs FM respectively, with no significant differences. 6m-PFS was 13% for LM vs 0% for the FM group (p=.39).Pts received a mean of 1.7 cycles (every 6 weeks) and 4.1 cycles (every 2 weeks) in LM and FM group, respectively. Thrombocytopenia was the most common serious side-effect, with a higher proportion of grade 1–2 toxicity in the FM group (p=.03) that also required more treatment delays (p=.01).

CONCLUSION

Despite being retrospective study and a few pts were treated with LM, there were no differences neither in PFS nor in OS in pts treated with LM vs FM at first or second line. Higher G1-2 thrombocytopenia was shown in the FM group probably due to a higher number of hematology samples collected.

SEOM clinical guideline for management of adult medulloblastoma (2020)

Recent advances in molecular profiling, have reclassified medulloblastoma, an undifferentiated tumor of the posterior fossa, in at least four diseases, each one with differences in prognosis, epidemiology and sensibility to different treatments. The recommended management of a lesion with radiological characteristics suggestive of MB includes maximum safe resection followed by a post-surgical MR < 48 h, LCR cytology and MR of the neuroaxis. Prognostic factors, such as presence of a residual tumor volume > 1.5 cm2, presence of micro- or macroscopic dissemination, and age > 3 years as well as pathological (presence of anaplastic or large cell features) and molecular findings (group, 4, 3 or p53 SHH mutated subgroup) determine the risk of relapse and should guide adjuvant management. Although there is evidence that both high-risk patients and to a lesser degree, standard-risk patients benefit from adjuvant craneoespinal radiation followed by consolidation chemotherapy, tolerability is a concern in adult patients, leading invariably to dose reductions. Treatment after relapse is to be considered palliative and inclusion on clinical trials, focusing on the molecular alterations that define each subgroup, should be encouraged. Selected patients can benefit from surgical rescue or targeted radiation or high-dose chemotherapy followed by autologous self-transplant. Even in patients that are cured by chemorradiation presence of significant sequelae is common and patients must undergo lifelong follow-up.

Phase I study of CC-90010, a reversible, oral BET inhibitor in patients with advanced solid tumors and relapsed/refractory non-Hodgkin's lymphoma

BACKGROUND

Bromodomain and extra-terminal (BET) proteins are epigenetic readers that regulate expression of genes involved in oncogenesis. CC-90010 is a novel, oral, reversible, small-molecule BET inhibitor.

PATIENTS AND METHODS

CC-90010-ST-001 (NCT03220347; 2015-004371-79) is a phase I dose-escalation and expansion study of CC-90010 in patients with advanced or unresectable solid tumors and relapsed/refractory (R/R) non-Hodgkin's lymphoma (NHL). We report results from the dose escalation phase, which explored 11 dose levels and four dosing schedules, two weekly (2 days on/5 days off; 3 days on/4 days off), one biweekly (3 days on/11 days off), and one monthly (4 days on/24 days off). The primary objectives were to determine the safety, maximum tolerated dose (MTD) and/or recommended phase II dose (RP2D) and schedule. Secondary objectives were to evaluate signals of early antitumor activity, pharmacokinetics, and pharmacodynamics.

RESULTS

This study enrolled 69 patients, 67 with solid tumors and two with diffuse large B-cell lymphoma (DLBCL). The median age was 57 years (range, 21-80) and the median number of prior regimens was four (range, 1-9). Treatment-related adverse events (TRAEs) were mostly mild and manageable; grade 3/4 TRAEs reported in more than two patients were thrombocytopenia (13%), anemia, and fatigue (4% each). Six patients had dose-limiting toxicities. MTDs were 15 mg (2 days on/5 days off), 30 mg (3 days on/11 days off), and 45 mg (4 days on/24 days off). The RP2D and schedule selected for expansion was 45 mg (4 days on/24 days off). As of 8 October 2019, one patient with grade 2 astrocytoma achieved a complete response, one patient with endometrial carcinoma had a partial response, and six patients had prolonged stable disease ≥11 months.

CONCLUSIONS

CC-90010 is well tolerated, with single-agent activity in patients with heavily pretreated, advanced solid tumors.

Association of breast cancer and obesity in a homogeneous population from Spain

OBJECTIVE

To evaluate for the first time in Spain if the association between obesity and breast cancer prognosis is similar to that reported in other countries with non Mediterranean dietary patterns.

METHODS

Weight and height and other variables of interest, tumor characteristics and current clinical status 3 yr after diagnosis were retrieved from medical files of breast cancer women diagnosed during 2006. A total of 159 cases with complete information were studied and categorized according to the World Health Organization criteria in normal-/under-weight, overweight, and obese.

RESULTS

Among breast cancer patients, 70.4% were classified as overweight/ obese and 29.6% as normal weight. Prevalence of obesity was high (38.4%) in comparison with information reported for healthy women of the same region (27.11%) and was higher among post-menopausal patients and in women with low level of alcohol and tobacco consumption. Moreover, overweight/ obese cases (79.5%) tended to have more often human epidermal growth factor receptor 2 status negative when compared with those with normal weight (70.2%; p=0.097) and the survival curves tended to be influenced by body mass index although without statistical significance.

CONCLUSIONS

Overweight/obesity in a Mediterranean country is highly prevalent among breast cancer patients. Our results support a putative influence of obesity per se and not the alimentary patterns as a prognostic factor in breast cancer patients justifying the need to perform larger prospective studies.

[Anesthesia with sevoflurane for tonsillectomy in a boy with Duchenne muscular dystrophy]

A 6-year-old boy with Duchenne muscular dystrophy (DMD) and foreseen difficult tracheal intubation underwent tonsillectomy under general inhaled anesthesia with sevoflurane. No neuromuscular blockers were administered and no perioperative complications emerged. In spite of advances in genetic diagnosis there continue to be patients with DMD because of spontaneous mutation of the dystrophin gene. Late detection leaves them vulnerable to administration of drugs like succinylcholine that can trigger fatal reactions involving hyperpotassemia, rhabdomyolysis, and malignant hyperthermia. Total intravenous anesthesia seems the best way to provide general anesthesia for a patient with DMD. Inhaled anesthesia is an alternative. Although halogenated agents can lead to rhabdomyolysis and malignant hyperthermia, the frequency seems low if we bear in mind that the use of sevoflurane is widespread in pediatrics. In this case sevoflurane induction facilitated safe tracheal intubation.