Myasthenia gravis: An emerging toxicity of immune checkpoint inhibitors

The advent of immunotherapy has heralded a number of significant advances in the treatment of particular malignancies associated with poor prognosis (melanoma, non-small-cell lung, renal and head/neck cancers). The success witnessed with therapeutic agents targeting cytotoxic T-lymphocyte-associated protein 4, programmed cell death protein 1 and programmed cell death ligand 1 immune checkpoints has inevitably led to an explosion in their clinical application and the subsequent recognition of specific toxicity profiles distinct from those long recognised with chemotherapy. Consequently, as the utility of such therapies broaden, understanding the nature, timing and management of these immune-related adverse events (irAEs) becomes increasingly significant. Although neurological irAEs are considered relatively rare in comparison with hepatitis, colitis, pneumonitis and endocrinopathies, one emerging side-effect is myasthenia gravis (MG). Among the 23 reported cases of immune checkpoint inhibitor-associated MG, 72.7% were de novo presentations, 18.2% were exacerbations of pre-existing MG and 9.1% were exacerbations of subclinical MG. The average onset of symptoms was within 6 weeks (range 2-12 weeks) of treatment initiation. In addition, there was no consistent association with elevated acetylcholine antibody titres and the development of immune checkpoint inhibitor-related MG. Significantly, there was a 30.4% MG-specific-related mortality, which further emphasises the importance of early recognition and robust treatment of this toxicity. In addition to a review of the existing literature, we present a new case of pembrolizumab-induced MG and provide insights into the underlying mechanisms of action of this phenomenon.

Tecemotide in unresectable stage III non-small-cell lung cancer in the phase III START study: updated overall survival and biomarker analyses

BACKGROUND

Tecemotide is a MUC1-antigen-specific cancer immunotherapy. The phase III START study did not meet its primary end point but reported notable survival benefit with tecemotide versus placebo in an exploratory analysis of the predefined patient subgroup treated with concurrent chemoradiotherapy. Here, we attempted to gain further insight into the effects of tecemotide in START.

PATIENTS AND METHODS

START recruited patients who did not progress following frontline chemoradiotherapy for unresectable stage III non-small-cell lung cancer. We present updated overall survival (OS) data and exploratory analyses of OS for baseline biomarkers: soluble MUC1 (sMUC1), antinuclear antibodies (ANA), neutrophil/lymphocyte ratio (NLR), lymphocyte count, and HLA type.

RESULTS

Updated OS data are consistent with the primary analysis: median 25.8 months (tecemotide) versus 22.4 months (placebo) (HR 0.89, 95% CI 0.77-1.03, P = 0.111), with ∼20 months additional median follow-up time compared with the primary analysis. Exploratory analysis of the predefined subgroup treated with concurrent chemoradiotherapy revealed clinically relevant prolonged OS with tecemotide versus placebo (29.4 versus 20.8 months; HR 0.81, 95% CI 0.68-0.98, P = 0.026). No improvement was seen with sequential chemoradiotherapy. High sMUC1 and ANA correlated with a possible survival benefit with tecemotide (interaction P = 0.0085 and 0.0022) and might have future value as biomarkers. Interactions between lymphocyte count, NLR, or prespecified HLA alleles and treatment effect were not observed.

CONCLUSION

Updated OS data support potential treatment benefit with tecemotide in patients treated with concurrent chemoradiotherapy. Exploratory biomarker analyses suggest that elevated sMUC1 or ANA levels correlate with tecemotide benefit.

CLINICALTRIALSGOV NUMBER

NCT00409188.

Erlotinib in non-small cell lung cancer (NSCLC): Interim safety analysis of the TRUST study

7645

Background: In patients (pts) with relapsed NSCLC, erlotinib 150 mg/d significantly prolonged survival, delayed symptom progression, and improved quality of life versus placebo (Shepherd et al, N Engl J Med 2005;353:123–32). TRUST is an open label, non- randomized trial initiated to provide erlotinib access to pts with advanced NSCLC. Methods: Eligible pts had stage IIIb/IV NSCLC, and had failed or were unsuitable for chemotherapy. Erlotinib (150 mg/d p.o.) was given until disease progression or unacceptable toxicity. Pts were monitored monthly. Results: In November 2006, data were available for 5,015 pts (ITT population) from 51 countries. Median age was 63y (range 19–95). Pt characteristics (%) were: male/female 62/38; Caucasian/Oriental/other 76/19/5; non-smoker/ex- or current-smoker 28/71 (no data 1); ECOG PS 0/1/2/3 21/53/20/6; adenocarcinoma/squamous cell/other 53/25/21; stage IIIb/IV 22/78; erlotinib 1st/2nd/3rd-line/other 14/48/37/1. Safety data were available for 4,423 pts, 55% of whom had at least one adverse event (AE). Only 5% had one or more erlotinib- related serious AEs, the most common being gastrointestinal (GI) disorders (86 pts; 63 grade [gr] 3/4). 6% of pts discontinued treatment due to erlotinib-related AEs: GI disorders in 96 pts (54 gr 3/4), skin disorders in 92 (50 gr 3/4). Unexpected erlotinib-related AEs occurred in 10% of pts (4% gr 1, 3% gr 2, 3% gr 3/4). As expected, rash was observed in 70% of pts, with the majority (84%) being of gr 1/2. 80% pts received >4 weeks of erlotinib. Among 4,405 pts, only 14% had dose reductions, mainly due to rash (83%) and diarrhea (21%). Similar safety results were seen for 2nd-line pts only. Efficacy for all and 2nd-line pts will be presented. Conclusions: These results, achieved through routine clinical use of erlotinib in unselected pts with advanced NSCLC, confirm the favorable tolerability profile seen with erlotinib in selected patients in the clinical trial setting.

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Anemia before and during concurrent chemoradiotherapy in patients with cervical carcinoma: Effect on progression-free survival

To determine the impact of anemia before and during chemoradiation in patients with cervical cancer, we collected data on hemoglobin (Hb) levels before and during treatment from 60 unselected patients with cervical carcinoma. All patients had FIGO stage IB to IVA disease and were treated with concurrent chemoradiation for the aim of cure. Patients with an Hb value below or equal to the lower 25th quartile were considered anemic. Progression-free survival (PFS) was evaluated by univariate and multivariate analyses. After a median follow-up of 26.3 months, 20 patients developed disease progression. The lowest Hb during chemoradiation (nadir Hb), the stage of disease, and parametrial involvement were correlated significantly with PFS. On multivariate analysis, the nadir Hb (relative risk [RR] 0.29) and tumor stage (RR 3.4) remained the only prognostically relevant factors predicting PFS. At 60 months the PFS was 39.1% for anemic patients and 48.0% for nonanemic patients (P < 0.0002). In patients undergoing chemoradiation for cervical carcinoma, a low nadir Hb is highly predictive of shortened PFS, whereas the Hb before treatment is prognostically not significant.

Anemia before and during concurrent chemoradiotherapy in patients with cervical carcinoma: Effect on progression-free survival

To determine the impact of anemia before and during chemoradiation in patients with cervical cancer, we collected data on hemoglobin (Hb) levels before and during treatment from 60 unselected patients with cervical carcinoma. All patients had FIGO stage IB to IVA disease and were treated with concurrent chemoradiation for the aim of cure. Patients with an Hb value below or equal to the lower 25th quartile were considered anemic. Progression-free survival (PFS) was evaluated by univariate and multivariate analyses. After a median follow-up of 26.3 months, 20 patients developed disease progression. The lowest Hb during chemoradiation (nadir Hb), the stage of disease, and parametrial involvement were correlated significantly with PFS. On multivariate analysis, the nadir Hb (relative risk [RR] 0.29) and tumor stage (RR 3.4) remained the only prognostically relevant factors predicting PFS. At 60 months the PFS was 39.1% for anemic patients and 48.0% for nonanemic patients (P < 0.0002). In patients undergoing chemoradiation for cervical carcinoma, a low nadir Hb is highly predictive of shortened PFS, whereas the Hb before treatment is prognostically not significant.

Impact of hemoglobin levels before and during concurrent chemoradiotherapy on the response of treatment in patients with cervical carcinoma: preliminary results

BACKGROUND

In patients undergoing radiation for cervical carcinoma, there is evidence that anemia is associated with an impaired outcome. For patients undergoing chemoradiation, there are no data available. The objective of this retrospective study was to examine the impact of anemia before and during chemoradiation in patients with cervical carcinoma.

METHODS

The authors collected data on hemoglobin (Hb) levels before and during treatment from 57 patients with cervical carcinoma. The stage of disease ranged between Stage IB and Stage IVA. All patients were treated with concurrent chemoradiation. Response to chemoradiation was evaluated by univariate and multivariate analyses.

RESULTS

The mean Hb level at the time of presentation was 12.9 +/- 1.6 g/dL in patients with a complete clinical response (CCR) and 12.1 +/- 1.4 g/dL in those with persistent disease (P = 0.126). In patients with a CCR, the mean nadir Hb level was 11.1 +/- 1.3 g/dL, and in patients with treatment failure, it was 9.8 +/- 1.8 g/dL (P = 0.008). A univariate logistic regression model demonstrated that the nadir Hb level was the most predictive factor for treatment failure (relative risk, 1.92; P = 0.015) followed by disease stage (relative risk, 0.51; P = 0.074). In a multivariate model, the nadir Hb level remained the only prognostically relevant factor predicting the response to chemoradiation. Only patients with nadir Hb values > 11 g/dL throughout chemoradiation had a more than 90% chance of achieving a CCR.

CONCLUSIONS

In patients undergoing chemoradiation for cervical carcinoma, the nadir Hb level is highly predictive of response to treatment, whereas the Hb level at the time of presentation is prognostically not significant.