Radiosensitizing Chemotherapy (Irinotecan) with Stereotactic Body Radiation Therapy for the Treatment of Inoperable Liver and/or Lung Metastases of Colorectal Cancer

UGT1A1 genotype-guided irinotecan dosing during neoadjuvant chemoradiotherapy for locally advanced rectal cancer: A prospective analysis of SN-38 concentration

Irinotecan plays a crucial role in the neoadjuvant chemoradiotherapy (nCRT) of rectal cancer, but its optimal dosing is still unclear. In this study, we included 101 eligible patients with the UGT1A1*28 genotype of UGT1A1*1*1 (74.3%) and UGT1A1*1*28 (25.7%) and UGT1A1*6 genotypes of GG (63.4%), GA (32.7%), and AA (3.9%). All patients received preoperative radiotherapy (50 Gy/25 fractions) with concurrent irinotecan (UGT1A1*1*1: 80 mg/m2 ; UGT1A1*1*28: 65 mg/m2 ) and capecitabine (CapIri). SN-38 concentrations were measured at 1.5, 24, and 49 h post-administration. Patients were divided into four groups (Q1-Q4) based on the SN-38 concentration. The complete-response (CR) rate was the primary endpoint. The analysis demonstrated that the 49 h SN-38 concentration was relatively optimal for predicting efficacy and toxicity. The Q4 group had a significantly higher CR rate than the Q1 group (p = .019), but also higher rates of adverse events (p = .009). We screened the recommended 49 h SN-38, with a 0.5-1.0 ng/mL concentration range. We also validated the correlation between UGT1A1*6 polymorphism and SN-38 concentration, along with the clinical efficacy of irinotecan. In conclusion, our study identified the relatively optimal timepoint and concentration range for monitoring SN38 concentrations and revealed the clinical significance of UGT1A1*6 and UGT1A1*28 polymorphisms in guiding irinotecan administration, offering meaningful insights for personalised irinotecan dosing.

Radiation therapy, tissue radiosensitization, and potential synergism in the era of novel antibody-drug conjugates

Antibody-drug conjugates (ADCs) represent a therapeutic class of agents designed to selectively deliver cytotoxic payloads to cancer cells. With the increasingly positioning of ADCs in the clinical practice, combinations with other treatment modalities, including radiation therapy (RT), will open new opportunities but also challenges. This review evaluates ADC-RT interactions, examining therapeutic synergies and potential caveats. ADC payloads can be radiosensitizing, enhancing cytotoxicity when used in combination with RT. Antigens targeted by ADCs can have various tissue expressions, resulting in possible off-target toxicities by tissue radiosensitization. Notably, the HER-2-directed ADC trastuzumab emtansine has appeared to increase the risk of radionecrosis when used concomitantly with brain RT, as glial cells can express HER2, too. Other possible organ-specific effects are discussed, such as pulmonary and cardiac toxicities. The lack of robust clinical data on the ADC-RT combination raises concerns regarding specific side effects and the ultimate trade-off of toxicity and safety of some combined approaches. Clinical studies are needed to assess ADC-RT combination safety and efficacy.

Multicenter, single-arm, phase II study (CAP) of radiotherapy plus liposomal irinotecan followed by camrelizumab and anti-angiogenic treatment in advanced solid tumors

Introduction

Combination therapeutic mode is likely to be the key to enhance the efficacy of immunotherapy in a wider range of cancer patients. Herein, we conducted an open-label, single-arm, multicenter, phase II clinical trial that enrolled patients with advanced solid tumors who had progressed after standard treatments.

Methods

Radiotherapy of 24 Gy/3 fractions/3-10 days was given to the targeted lesions. Liposomal irinotecan (80mg/m2, dose could be adjusted to 60 mg/m2 for intolerable cases) was intravenously (IV) administered once within 48 hours after radiotherapy. Then, camrelizumab (200mg IV, q3w) and anti-angiogenic drugs were given regularly until disease progression. The primary endpoint was objective response rate (ORR) in the target lesions evaluated by investigators per RECIST 1.1. The secondary endpoints were disease control rate (DCR) and treatment-related adverse events (TRAEs).

Results

Between November 2020 and June 2022, 60 patients were enrolled. The median follow-up was 9.0 months (95% confidence interval (CI) 5.5-12.5). Of 52 evaluable patients, the overall ORR and DCR were 34.6% and 82.7%, respectively. Fifty patients with target lesions were evaluable, the ORR and DCR of the target lesions were 35.3% and 82.4%, respectively. The median progression-free survival was 5.3 months (95% CI 3.6, 6.2), and the median overall survival was not reached. TRAEs (all grades) occurred in 55 (91.7%) patients. The most common grade 3-4 TRAEs were lymphopenia (31.7%), anemia (10.0%), and leukopenia (10.0%).

Conclusion

The combination of radiotherapy, liposomal irinotecan, camrelizumab, and anti-angiogenesis therapy demonstrated promising anti-tumor activity and well tolerance in various advanced solid tumors.

Clinical trial registration

https://clinicaltrials.gov/ct2/home, identifier NCT04569916.

Superparamagnetic Iron Oxide Nanoparticles (SPION): From Fundamentals to State-of-the-Art Innovative Applications for Cancer Therapy

Despite significant advances in cancer therapy over the years, its complex pathological process still represents a major health challenge when seeking effective treatment and improved healthcare. With the advent of nanotechnologies, nanomedicine-based cancer therapy has been widely explored as a promising technology able to handle the requirements of the clinical sector. Superparamagnetic iron oxide nanoparticles (SPION) have been at the forefront of nanotechnology development since the mid-1990s, thanks to their former role as contrast agents for magnetic resonance imaging. Though their use as MRI probes has been discontinued due to an unfavorable cost/benefit ratio, several innovative applications as therapeutic tools have prompted a renewal of interest. The unique characteristics of SPION, i.e., their magnetic properties enabling specific response when submitted to high frequency (magnetic hyperthermia) or low frequency (magneto-mechanical therapy) alternating magnetic field, and their ability to generate reactive oxygen species (either intrinsically or when activated using various stimuli), make them particularly adapted for cancer therapy. This review provides a comprehensive description of the fundamental aspects of SPION formulation and highlights various recent approaches regarding in vivo applications in the field of cancer therapy.