Are intra-pleural bacterial products associated with longer survival in adults with malignant pleural effusions? A systematic review

Engineered lactococcus lactis intrapleural therapy promotes regression of malignant pleural effusion by enhancing antitumor immunity

Intrapleural immunotherapies have emerged as a prominent field in treating malignant pleural effusion (MPE). Among these, bacteria-based intrapleural therapy has exerted an anti-MPE effect by immuno-stimulating or cytotoxic properties. We previously engineered a probiotic Lactococcus lactis (FOLactis) expressing a fusion protein of Fms-like tyrosine kinase 3 and co-stimulator OX40 ligands. FOLactis activates tumor antigen-specific immune responses and displays systemic antitumor efficacy via intratumoral delivery. However, no available lesions exist in the pleural cavity of patients with MPE for intratumoral administration. Therefore, we further optimize FOLactis to treat MPE through intrapleural injection. Intrapleural administration of FOLactis (I-Pl FOLactis) not only distinctly suppresses MPE and pleural tumor nodules, but also significantly extends noticeable survival in MPE-bearing murine models. The proportion of CD103+ dendritic cells (DCs) in tumor-draining lymph nodes increases three-fold in FOLactis group, compared to the wild-type bacteria group. The enhanced DCs recruitment promotes the infiltration of effector memory T and CD8+ T cells, as well as the activation of NK cells and the polarization of macrophages to M1. Programmed death 1 blockade antibody combination further enhances the antitumor efficacy of I-Pl FOLactis. In summary, we first develop an innovative intrapleural strategy based on FOLactis, exhibiting remarkable efficacy and favorable biosafety profiles. These findings suggest prospective clinical translation of engineered probiotics for managing MPE through direct administration into the pleural cavity.

A trial of intra-pleural bacterial immunotherapy in malignant pleural mesothelioma (TILT) - a randomised feasibility study using the trial within a cohort (TwiC) methodology

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive thoracic malignancy with a poor prognosis. Systemic immunotherapy is an effective frontline treatment for MPM, and there is a scientific rationale supporting the possible efficacy of local, i.e. intra-pleural immune modulators. Trial of intra-pleural bacterial immunotherapy (TILT) investigated the feasibility of performing a randomised trial of intra-pleural bacterial immunotherapy in people with MPM, using the trials within cohorts (TwiC) methodology.

METHODS

TILT was a multicentre, three-armed, randomised, feasibility TwiC of intra-pleural OK432, BCG, or usual care in people with MPM. Eligible participants were identified from within the ASSESS-meso study, a prospective, longitudinal, observational cohort study, and were randomly selected to be offered a single dose of OK432 or BCG, via an indwelling pleural catheter. The primary outcome was feasibility, evaluated against prespecified recruitment, attrition and data completeness targets. The acceptability of trial processes and interventions was assessed during qualitative interviews with participants and family members at the end of the trial. TILT was registered prospectively on the European Clinical Trials Registry (EudraCT number 2016-004,727-23) and the ISRCTN Register on 04 December 2017.

RESULTS

Seven participants were randomised from a planned sample size of 12; thus, the 66% recruitment rate target was not met. Two participants withdrew after randomisation, breaching the pre-stated attrition threshold of 10%. It was not possible to maintain blinding of control participants, which negated a fundamental tenet of the TwiC design. The trial processes and methodology were generally acceptable to participants and relatives, despite several recipients of intra-pleural bacterial agents experiencing significant local and systemic inflammatory responses.

CONCLUSION

It was possible to design a clinical trial of an investigational medicinal product based on the TwiC design and to obtain the necessary regulatory approvals. However, whilst acceptable to participants and relatives, the TwiC design was not a feasible method of investigating intra-pleural bacterial immunotherapy in people with MPM. Future trials investigating this topic should consider the eligibility constraints and recruitment difficulties encountered.

TRIAL REGISTRATION

TILT was registered prospectively on the European Clinical Trials Registry (EudraCT number 2016-004727-23 ) and the ISRCTN Register ( 10432197 ) on 04 December 2017.

Narrative review of theoretical considerations regarding HITHOC between past and future

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Survival in patients with malignant pleural effusion undergoing talc pleurodesis

OBJECTIVES

Recent observations indicate a potential survival benefit in patients with malignant pleural effusion (MPE) who achieve successful pleurodesis in comparison to patients who experience effusion recurrence post pleurodesis. This study aimed to explore this observation using two datasets of patients with MPE undergoing talc pleurodesis.

MATERIALS AND METHODS

Dataset 1 comprised patients who underwent talc pleurodesis at Oxford Pleural Unit for MPE. Dataset 2 comprised patients enrolled in the TIME1 clinical trial. Pleurodesis success was defined as absence of need for further therapeutic procedures for MPE in the three months following pleurodesis. Data on various clinical, laboratory and radiological parameters were collected and survival was compared according to pleurodesis outcome (success vs. failure) after adjusting for the aforementioned parameters.

RESULTS

Dataset 1 comprised 60 patients with mean age 74.1±10.3 years. The most common primary malignancies were mesothelioma, breast and lung cancer. 29 patients (48.3%) achieved pleurodesis. The adjusted odds ratio (aOR) for poor survival with pleurodesis failure was 2.85 (95% CI 1.08-7.50, =p 0.034). Dataset 2 comprised 259 patients from the TIME1 trial. The mean age was 70.8±10.3 and the most common primary malignancies were mesothelioma, lung and breast cancer. Pleurodesis was successful in 205 patients (79%). aOR for poor survival was 1.62 (95% CI 1.09-2.39, p = 0.015).

CONCLUSION

Achieving pleurodesis seems to impart a survival benefit in patients with MPE. Further studies are required to explore factors that may contribute to this phenomenon and to address the difference in survival between pleurodesis and indwelling pleural catheter interventions.

Is pleural infection associated with longer survival in mesothelioma? A population-based cohort study using data from Hospital Episode Statistics

BACKGROUND

Historically pleural infection was thought to be associated with longer survival in thoracic malignancies. The aim of this population-based cohort study was to investigate this hypothesis in mesothelioma, using national data from a high incidence country.

METHODS

Case records for all patients with mesothelioma seen in English hospitals between 01/01/2005 and 31/12/2014 were extracted from Hospital Episode Statistics using International Classification of Diseases Tenth Edition (ICD-10) codes. Episodes of pleural infection were identified. Linked mortality data was obtained from the Office of National Statistics. The primary outcome was all-cause mortality. The explanatory variable was pleural infection. Cox proportional hazards model was used to analyse survival, with pleural infection, chemotherapy and thoracic surgery handled as time-variable co-factors.

RESULTS

Of 22,215 patients with mesothelioma, 512 (2.3%) developed pleural infection at some point in their illness. Overall median survival was 7.0 months (IQR 2.3-16.4). Pleural infection was associated with shorter survival in the immediate post-infection period (up to 30 days - HR 1.81, 95% CI 1.45-2.22) and longer term (>30 days - HR 1.81, 95% CI 1.63-1.99). Other factors associated with increased mortality were age, male gender and being diagnosed as an inpatient. Receiving chemotherapy and being less economically deprived were associated with longer survival.

CONCLUSION

Pleural infection occurred in 2.3% of people with mesothelioma and was associated with shorter survival. This refutes previous reports suggesting pleural infection may be associated with better outcomes in thoracic malignancy.