Lumeneye digital proctoscopy is safe and streamlines management of immune checkpoint inhibitor induced colitis

Introduction

Immune checkpoint inhibitors (CPI) have transformed cancer outcomes, but at the cost of inducing CPI-colitis in up to 46%, frequently leading to morbidity and CPI discontinuation. Diagnosis is via endoscopy, with >90% exhibiting inflammation involving the distal colon. The rising prevalence of CPI-colitis has increased pressure on endoscopy services, delaying patient management. Use of the Lumeneye, a low-cost GI digital proctoscope with biopsy ports, may be valuable in streamlining patient pathways.

Methods

A single centre, prospective observational feasibility study (Royal Marsden Hospital, London UK). Consecutive patients with CPI-induced diarrhoea underwent Lumeneye proctoscopy and rectal biopsy sampling in the outpatient clinic. Digital photographs +/- video recordings were captured, and clinical data obtained from the electronic patient record. Patient reported comfort scores were assessed using the Modified Gloucester Comfort Scale (MGCS) and where applicable, compared to standard lower GI endoscopy.

Results

Twenty-two Lumeneye procedures were performed on 18 patients (11 males, 7 females, median age 64 years). Cancers included melanoma (n=8), renal (n=2), upper GI (n=1), head and neck (n=1), prostate (n=2), pancreatic (n=1) or lung cancer (n=3). Nine received anti-PD-1/PD-L1 monotherapy, 9 received combination anti-CTLA-4/anti-PD-1. The mean time from referral to either Lumeneye examination or lower GI endoscopy was 5 (IQR 3–7) and 28 days (IQR 18–34) respectively (p<0.001). The mean procedure time was 3 (IQR 2–4) minutes. Lumeneye was well tolerated and associated with a significantly lower MGCS score compared to standard lower GI endoscopy (2 -minimal discomfort vs 3-mild discomfort, respectively, p<0.05). Endoscopic findings included normal mucosa in 11, with the remainder exhibiting varying degrees of oedema, erythema and erosions (figure 1). Four patients had lower GI endoscopy within 3 weeks of Lumeneye, with excellent concordance between endoscopic and histological findings. In 2 patients awaiting flexible sigmoidoscopy, Lumeneye expedited a diagnosis of severe CPI-colitis that necessitated escalation to anti-TNF therapy. In another 6, presence of macroscopically normal mucosa informed the rationale for a rapid corticosteroid taper with administration of topical corticosteroids (Clipper).

Conclusion

Examination of patients with CPI-colitis in the physician’s office using Lumeneye was safe, well tolerated and reduced the burden on endoscopy services. Lumeneye streamlined the patient pathway by facilitating early diagnosis allowing timely escalation or de-escalation of immunosuppressive therapy.