Bone marrow toxicity and immune reconstitution in melanoma and non-melanoma solid cancer patients after non-myeloablative conditioning with chemotherapy and checkpoint inhibition

Real-World Assessment of Recommended COVID-19 Vaccination Waiting Period after Chemotherapy

There is a knowledge gap concerning the proper timing for COVID-19 vaccination in cancer patients undergoing chemotherapy. We aimed to evaluate the suitability of the guidelines that recommend waiting at least three months after undergoing chemotherapy before receiving a COVID-19 vaccine. This retrospective cohort study used aggregated data from the TriNetX US Collaboratory network. Participants were grouped into two groups based on the interval between chemotherapy and vaccination. The primary outcome assessed was infection risks, including COVID-19; skin, intra-abdominal, and urinary tract infections; pneumonia; and sepsis. Secondary measures included healthcare utilization and all causes of mortality. Kaplan-Meier analysis and the Cox proportional hazard model were used to calculate the cumulative incidence and hazard ratio (HR) and 95% confidence intervals for the outcomes. The proportional hazard assumption was tested with the generalized Schoenfeld approach. Four subgroup analyses (cancer type, vaccine brand, sex, age) were conducted. Sensitivity analyses were performed to account for competing risks and explore three distinct time intervals. Patients receiving a vaccine within three months after chemotherapy had a higher risk of COVID-19 infection (HR: 1.428, 95% CI: 1.035-1.970), urinary tract infection (HR: 1.477, 95% CI: 1.083-2.014), and sepsis (HR: 1.854, 95% CI: 1.091-3.152) compared to those who adhered to the recommendations. Hospital inpatient service utilization risk was also significantly elevated for the within three months group (HR: 1.692, 95% CI: 1.354-2.115). Adhering to a three-month post-chemotherapy waiting period reduces infection and healthcare utilization risks for cancer patients receiving a COVID-19 vaccine.

Tumor-Infiltrating Lymphocytes and Adoptive Cell Therapy: State of the Art in Colorectal, Breast and Lung Cancer

Our knowledge of tumor-infiltrating lymphocytes (TILs) is dramatically expanding. These cells have proven prognostic and therapeutic value for many cancer outcomes and potential to treat also disseminated breast, colorectal, or lung cancer. However, the therapeutical outcome of TILs is negatively affected by tumor mutational burden and neoantigens. On the other hand, it can be improved in combination with checkpoint blockade therapy. This knowledge and rapid detection techniques alongside gene editing allow us to classify and modify T cells in many ways. Hence, to tailor them precisely to the patient´s needs as to program T cell receptors to recognize specific tumor-associated neoantigens and to insert them into lymphocytes or to select tumor neoantigen-specific T cells, for the development of vaccines that recognize tumor-specific antigens in tumors or metastases. Further studies and clinical trials in the field are needed for an even better-detailed understanding of TILs interactions and aiming in the fight against multiple cancers.

TIL Therapy: Facts and Hopes

After a positive phase III trial, it is evident that treatment with tumor-infiltrating lymphocytes (TIL) is a safe, feasible, and effective treatment modality for patients with metastatic melanoma. Further, the treatment is safe and feasible in diverse solid tumors, regardless of the histologic type. Still, TIL treatment has not obtained the regulatory approvals to be implemented on a larger scale. Therefore, its availability is currently restricted to a few centers worldwide. In this review, we present the current knowledge of TIL therapy and discuss the practical, logistic, and economic challenges associated with implementing TIL therapy on a larger scale. Finally, we suggest strategies to facilitate the widespread implementation of TIL therapy and approaches to develop the next generation of TILs.

First in man study: Bcl-Xl_42-CAF®09b vaccines in patients with locally advanced prostate cancer

Background

The B-cell lymphoma-extra-large (Bcl-XL) protein plays an important role in cancer cells’ resistance to apoptosis. Pre-clinical studies have shown that vaccination with Bcl-XL-derived peptides can induce tumor-specific T cell responses that may lead to the elimination of cancer cells. Furthermore, pre-clinical studies of the novel adjuvant CAF®09b have shown that intraperitoneal (IP) injections of this adjuvant can improve the activation of the immune system. In this study, patients with hormone-sensitive prostate cancer (PC) received a vaccine consisting of Bcl-XL-peptide with CAF®09b as an adjuvant. The primary aim was to evaluate the tolerability and safety of IP and intramuscular (IM) administration, determine the optimal route of administration, and characterize vaccine immunogenicity.

Patients and methods

Twenty patients were included. A total of six vaccinations were scheduled: in Group A (IM to IP injections), ten patients received three vaccines IM biweekly; after a three-week pause, patients then received three vaccines IP biweekly. In Group B (IP to IM injections), ten patients received IP vaccines first, followed by IM under a similar vaccination schedule. Safety was assessed by logging and evaluating adverse events (AE) according to Common Terminology Criteria for Adverse Events (CTCAE v. 4.0). Vaccines-induced immune responses were analyzed by Enzyme-Linked Immunospot and flow cytometry.

Results

No serious AEs were reported. Although an increase in T cell response against the Bcl-XL-peptide was found in all patients, a larger proportion of patients in group B demonstrated earlier and stronger immune responses to the vaccine compared to patients in group A. Further, we demonstrated vaccine-induced immunity towards patient-specific CD4, and CD8 T cell epitopes embedded in Bcl-XL-peptide and an increase in CD4 and CD8 T cell activation markers CD107a and CD137 following vaccination. At a median follow-up of 21 months, no patients had experienced clinically significant disease progression.

Conclusion

The Bcl-XL-peptide-CAF®09b vaccination was feasible and safe in patients with l hormone-sensitive PC. In addition, the vaccine was immunogenic and able to elicit CD4 and CD8 T cell responses with initial IP administration eliciting early and high levels of vaccine-specific responses in a higher number og patients.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT03412786.

Tumor-infiltrating lymphocytes for adoptive cell therapy: recent advances, challenges, and future directions

INTRODUCTION

Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) is a highly personalized type of cancer immunotherapy. TIL-based ACT exploits naturally occurring TILs, derived from the patients' tumor. This treatment has shown consistent clinical responses in melanoma, and recent results point toward a potential use in multiple cancer diagnoses. However, several limitations have restricted the clinical development and adaptation of TIL-based ACT.

AREAS COVERED

In this review, we present the principles of TIL-based ACT and discuss the most significant limitations for therapeutic efficacy and its widespread application. The topics of therapeutic resistance (both innate and acquired), treatment-related toxicity, and the novel research topic of metabolic barriers in the tumor microenvironment (TME) are covered.

EXPERT OPINION

There are many ongoing areas of research focusing on improving clinical efficacy and optimizing TIL-based ACT. Many strategies have shown great potential, particularly strategies advancing TIL efficacy (such as increasing and harnessing ex vivo the sub-population of tumor-reactive TILs) and manufacturing processes. Novel approaches can help overcome current limitations and potentially result in TIL-based ACT entering the mainstream of cancer therapy across tumor types.

Adoptive cell therapy with tumor-infiltrating lymphocytes supported by checkpoint inhibition across multiple solid cancer types

Background

Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TILs) has shown remarkable results in malignant melanoma (MM), while studies on the potential in other cancer diagnoses are sparse. Further, the prospect of using checkpoint inhibitors (CPIs) to support TIL production and therapy remains to be explored.

Study design

TIL-based ACT with CPIs was evaluated in a clinical phase I/II trial. Ipilimumab (3 mg/kg) was administered prior to tumor resection and nivolumab (3 mg/kg, every 2 weeks ×4) in relation to TIL infusion. Preconditioning chemotherapy was given before TIL infusion and followed by low-dose (2 10e6 international units (UI) ×1 subcutaneous for 14 days) interleukin-2 stimulation.

Results

Twenty-five patients covering 10 different cancer diagnoses were treated with in vitro expanded TILs. Expansion of TILs was successful in 97% of recruited patients. Five patients had sizeable tumor regressions of 30%–63%, including two confirmed partial responses in patients with head-and-neck cancer and cholangiocarcinoma. Safety and feasibility were comparable to MM trials of ACT with the addition of expected CPI toxicity. In an exploratory analysis, tumor mutational burden and expression of the alpha-integrin CD103 (p=0.025) were associated with increased disease control. In vitro tumor reactivity was seen in both patients with an objective response and was associated with regressions in tumor size (p=0.028).

Conclusion

High success rates of TIL expansion were demonstrated across multiple solid cancers. TIL ACTs were found feasible, independent of previous therapy. Tumor regressions after ACT combined with CPIs were demonstrated in several cancer types supported by in vitro antitumor reactivity of the TILs.

Trial registration numbers

NCT03296137, and EudraCT No. 2017-002323-25.