Phase II trial of domatinostat (4SC-202) in combination with avelumab in patients with previously treated advanced mismatch repair proficient oesophagogastric and colorectal adenocarcinoma: EMERGE

BACKGROUND

Most oesophagogastric adenocarcinomas (OGAs) and colorectal cancers (CRCs) are mismatch repair proficient (MMRp), responding poorly to immune checkpoint inhibition. We evaluated the safety and efficacy of domatinostat (histone deacetylase inhibitor) plus avelumab (anti-PD-L1 antibody) in patients with previously treated inoperable, advanced/metastatic MMRp OGA and CRC.

PATIENTS AND METHODS

Eligible patients were evaluated in a multicentre, open-label dose escalation/dose expansion phase II trial. In the escalation phase, patients received escalating doses of domatinostat [100 mg once daily (OD), 200 mg OD, 200 mg twice daily (BD)] orally for 14 days followed by continuous dosing plus avelumab 10 mg/kg administered intravenously 2-weekly (2qw) to determine the recommended phase II dose (RP2D). The trial expansion phase evaluated the best objective response rate (ORR) during 6 months by RECIST version 1.1 using a Simon two-stage optimal design with 2/9 and 1/10 responses required to proceed to stage 2 in the OGA and CRC cohorts, respectively.

RESULTS

Patients (n = 40) were registered between February 2019 and October 2021. Patients in the dose escalation phase (n = 12) were evaluated to confirm the RP2D of domatinostat 200 mg BD plus avelumab 10 mg/kg. No dose-limiting toxicities were observed. Twenty-one patients were treated at the RP2D, 19 (9 OGA and 10 CRC) were assessable for the best ORR; 2 patients with CRC did not receive combination treatment and were not assessable for the primary endpoint analysis. Six patients were evaluated in the dose escalation and expansion phases. In the OGA cohort, the best ORR was 22.2% (95% one-sided confidence interval lower bound 4.1) and the median duration of disease control was 11.3 months (range 9.9-12.7 months). No responses were observed in the CRC cohort. No treatment-related grade 3-4 adverse events were reported at the RP2D.

CONCLUSIONS

Responses in the OGA cohort met the criteria to expand to stage 2 of recruitment with an acceptable safety profile. There was insufficient signal in the CRC cohort to progress to stage 2.

TRIAL REGISTRATION

NCT03812796 (registered 23rd January 2019).

A survey of liver ablation amongst UK interventional radiologists

AIM

To characterise training for, and conduct of, image-guided liver tumour ablation amongst UK interventional radiologists.

MATERIALS AND METHODS

A web-based survey of British Society of Interventional Radiology members was carried out between 31 August to 1 October 2022. Twenty-eight questions were designed, covering four domains: (1) respondent background, (2) training, (3) current practice, and (4) operator technique.

RESULTS

One hundred and six responses were received, with an 87% completion rate and an approximate response rate of 13% of society members. All UK regions were represented, with the majority from London (22/105, 21%). Seventy-two out of 98 (73%) were either extremely or very interested in learning about liver ablation during training, although levels of exposure varied widely, and 37/103 (36%) had no exposure. Performed numbers of cases also varied widely, between 1-10 cases and >100 cases per operator annually. All (53/53) used microwave energy, and most routinely used general anaesthesia (47/53, 89%). Most 33/53 (62%) did not have stereotactic navigation system, and 25/51(49%) always, 18/51 (35%) never, and 8/51(16%) sometimes gave contrast medium (mean 40, SD 32%) after procedures. Fusion software to judge ablation completeness was never used by 86% (43/55), sometimes used by 9% (5/55), and always used by 13% (7/55) of respondents.

CONCLUSION

Although there are high levels of interest in image-guided liver ablation amongst UK interventional radiologists, training arrangements, operator experience, and procedural technique vary widely. As image-guided liver ablation evolves, there is a growing need to standardise training and techniques, and develop the evidence base to ensure high-quality oncological outcomes.

Percutaneous cryoablation for desmoid fibromatosis: initial experience at a UK centre

AIM

To report the first UK experience of cryoablation in desmoid fibromatosis (DF) with particular focus on technique, safety, and efficacy.

MATERIALS AND METHODS

Patients were selected at multidisciplinary tumour board meetings at a specialist cancer hospital. Radiation dose, procedure duration, and number of cryoprobes were compared for small versus large tumours (>10 cm long axis). Response at magnetic resonance imaging (MRI) was evaluated using different criteria, and percentage agreement with clinical response as assessed in oncology clinic calculated.

RESULTS

Thirteen procedures were performed in 10 patients (eight women, median age 51 years, IQR 42-69 years) between February 2019 and August 2021. Procedures for large tumours had higher radiation dose (2,012 ± 1,012 versus 1,076 ± 519 mGy·cm, p=0.048) used more cryoprobes (13 ± 7 versus 4 ± 2, p=0.009), and were more likely to have residual unablated tumour (38 ± 37% versus 7.5 ± 10%, p=0.045). Adverse events were minor apart from one transient radial nerve palsy. Eight of 10 patients had symptomatic benefit at clinical follow-up (median 353 days, IQR 86-796 days), and three started systemic therapy mean 393 days later. All patients who had complete ablation demonstrated symptomatic response, with no instances of repeat treatment, recurrence, or need for systemic therapy during the study period. All progression occurred outside ablation zones.

CONCLUSION

Cryoablation for symptomatic DF is a reproducible technique with low, transient toxicity, where one or two treatments can achieve a meaningful response. Where possible, the ablation ice ball should fully cover DF tumours.

Multiparametric whole-body 3.0-T MRI in newly diagnosed intermediate- and high-risk prostate cancer: diagnostic accuracy and interobserver agreement for nodal and metastatic staging

OBJECTIVES

To determine the diagnostic accuracy and interobserver concordance of whole-body (WB)-MRI, vs. 99mTc bone scintigraphy (BS) and 18fluoro-ethyl-choline (18F-choline) PET/CT for the primary staging of intermediate/high-risk prostate cancer.

METHODS

An institutional review board approved prospective cohort study carried out between July 2012 and November 2015, whereby 56 men prospectively underwent 3.0-T multiparametric (mp)-WB-MRI in addition to BS (all patients) ± 18F-choline PET/CT (33 patients). MRI comprised pre- and post-contrast modified Dixon (mDixon), T2-weighted (T2W) imaging, and diffusion-weighted imaging (DWI). Patients underwent follow-up mp-WB-MRI at 1 year to derive the reference standard. WB-MRIs were reviewed by two radiologists applying a 6-point scale and a locked sequential read (LSR) paradigm for the suspicion of nodal (N) and metastatic disease (M1a and M1b).

RESULTS

The mean sensitivity/specificity of WB-MRI for N1 disease was 1.00/0.96 respectively, compared with 1.00/0.82 for 18F-choline PET/CT. The mean sensitivity and specificity of WB-MRI, 18F-choline PET/CT, and BS were 0.90/0.88, 0.80/0.92, and 0.60/1.00 for M1b disease. ROC-AUC did not show statistically significant improvement for each component of the LSR; mean ROC-AUC 0.92, 0.94, and 0.93 (p < 0.05) for mDixon + DWI, + T2WI, and + contrast respectively. WB-MRI had an interobserver concordance (κ) of 0.79, 0.68, and 0.58 for N1, M1a, and M1b diseases respectively.

CONCLUSIONS

WB-MRI provides high levels of diagnostic accuracy for both nodal and metastatic bone disease, with higher levels of sensitivity than BS for metastatic disease, and similar performance to 18F-choline PET/CT. T2 and post-contrast mDixon had no significant additive value above a protocol comprising mDixon and DWI alone.

KEY POINTS

• A whole-body MRI protocol comprising unenhanced mDixon and diffusion-weighted imaging provides high levels of diagnostic accuracy for the primary staging of intermediate- and high-risk prostate cancer. • The diagnostic accuracy of whole-body MRI is much higher than that of bone scintigraphy, as currently recommended for clinical use. • Staging using WB-MRI, rather than bone scintigraphy, could result in better patient stratification and treatment delivery than is currently provided to patients worldwide.

Perivascular extension of microwave ablation zone: demonstrated using an ex vivo porcine perfusion liver model<sup/>

Microwave ablation (MWA) has been proposed to suffer less from the heat sink effect compared to radiofrequency ablation but has been reported to cause extension of the ablation zone along intrahepatic vessels in clinical practice. To study this effect in detail, eight fresh porcine livers were perfused in an ex vivo organ perfusion system. Livers were perfused with oxygenated, O-positive human blood at 37 °C. Perfusion was discontinued immediately before ablation in the non-perfused group (n = 4) whilst in the perfused group (n = 4) perfusion was maintained during MWA (140 W X 2 min). Large intrahepatic vessels (> 6 mm) were avoided using ultrasound. MWA zones were bisected within 30 min of perfusion termination and sections were fixed in formalin and stained with H&E and NADH to assess cell viability. Magnetic resonance imaging (MRI) was performed on two livers (one perfused, one non-perfused) to provide imaging correlation before sectioning. Twenty-one out of a total of 30 MW ablation zones (70%) showed extension of the ablation zone along a vessel. There was no statistically significant difference (p = 1) in the incidence of ablation zone extension between perfused (9/13, 69%) and non-perfused organs (12/17, 71%). MRI also demonstrated ablation zone extension along blood vessels correlating with macroscopy in two livers. NADH staining also confirmed extension of the ablation zone. Liver MWA appears to be commonly associated with propagated thermal injury along adjacent vessels and occurs independent of active blood flow. In order to avoid possible complications through non-target tissue injury, this effect requires further investigation.

Apparatus for Histological Validation of In Vivo and Ex Vivo Magnetic Resonance Imaging of the Human Prostate

This article describes apparatus to aid histological validation of magnetic resonance imaging studies of the human prostate. The apparatus includes a 3D-printed patient-specific mold that facilitates aligned in vivo and ex vivo imaging, in situ tissue fixation, and tissue sectioning with minimal organ deformation. The mold and a dedicated container include MRI-visible landmarks to enable consistent tissue positioning and minimize image registration complexity. The inclusion of high spatial resolution ex vivo imaging aids in registration of in vivo MRI and histopathology data.

Perivascular parenchymal extension of the ablation zone following liver microwave ablation

A 69-year-old man who presented with abdominal discomfort was, on examination, found to have a palpable abdominal mass. Contrast-enhanced CT showed a mass arising from the inferior vena cava, which biopsy confirmed to be a leiomyosarcoma. One month after chemoradiotherapy, CT demonstrated a new 15 mm solitary central right liver metastasis. Microwave ablation (MWA) of the metastasis was performed using an Acculis Sulis V system (Angiodynamics, USA) at a power of 140 Watts for 4 min, with no immediate complications. After 1 month, MRI with gadolinium was performed to assess the liver ablation zone. The MRI demonstrated thrombosis of a right inferior hepatic vein branch leading to the ablation zone and extension of the ablation zone 1 cm into the tissue around the thrombosed vessel.

Excimer laser treatment of spherical hyperopia: PRK or LASIK?

PURPOSE

To compare the efficacy and safety of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in the treatment of spherical hyperopia with use of the VISX STAR S2 excimer laser.

METHODS

A review of 15 consecutive patients (22 eyes) receiving PRK and 22 consecutive patients (26 eyes) receiving LASIK (median follow-up, 12 months).

RESULTS

Mean age was 52 +/- 7 years for patients receiving PRK and 55 +/- 9 years for patients receiving LASIK. Mean preoperative spherical equivalent was +2.25 +/- 1.16 D for PRK patients and +1.81 +/- 0.92 D for LASIK patients. Mean deviation from intended correction was -0.82 +/- 0.89 D after PRK and +0.19 +/- 0.47 D after LASIK at 1 month (P < .01); +0.16 D +/- 0.37 D after PRK and +0.29 +/- 0.51 D after LASIK at 6 months (P = .906); +0.20 +/- 0.35 D after PRK and +0.37 +/- 0.44 D after LASIK at 1 year (P = .301). At 1 year, 83.3% of PRK eyes and 61.5% of hyperopic LASIK eyes were within +/- 0.50 D of intended correction (P = 1.0). At 1 year, all eyes in both groups had acuity of 20/40 or better uncorrected, and 47.1% of PRK eyes and 54.5% of LASIK eyes had acuity of 20/20 or better uncorrected (P = 1.0). At last follow-up (minimum, 6 months), 2 eyes in each group had lost 2 lines of best spectacle-correct visual acuity, but none had lost more than 2 lines. All PRK patients experienced significant postoperative pain that required systemic medication. LASIK patients had only minor, transient discomfort.

CONCLUSION

LASIK and PRK are of comparable efficacy and safety. However, PRK was associated with significant post-operative pain, an initial and temporary myopic overshoot peaking at 1 month, and stability not occurring before 6 months. LASIK was less painful and was associated with more rapid stability (at 1 month) and a trend toward better uncorrected visual acuity, although not statistically significant.