Atezolizumab (Tecentriq▼) and other immune-stimulatory anti-cancer drugs: risk of severe cutaneous adverse reactions (SCARs)

Cases of severe cutaneous adverse reactions, including Stevens-Johnsons syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported in patients treated with immune-stimulatory anti-cancer drugs, including atezolizumab. Advise patients to be vigilant for the signs of severe skin reactions and to seek urgent medical advice if they occur.

Advice for healthcare professionals:

  • severe cutaneous adverse reactions (SCARs), including cases of Stevens-Johnsons syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported in patients treated with immune-stimulatory anti-cancer drugs including atezolizumab
  • advise patients of the need to seek urgent medical assistance if severe skin reactions occur
  • monitor patients for signs and symptoms of severe skin reactions and exclude other causes
  • if a SCAR is suspected, treatment should be withheld, and patients referred to a specialist for diagnosis and treatment
  • if SJS or TEN is confirmed, or for any grade 4 (life-threatening) SCAR, permanently discontinue treatment with the immune-stimulatory drug
  • caution is recommended when considering the use of immune-stimulatory drugs associated with SCARs in patients with previous history of life-threatening SCAR with other immune-stimulatory anti-cancer drugs
  • report suspected adverse drug reactions on a Yellow Card – all suspected adverse drug reactions to black triangle medicines should be reported

Advice for healthcare professionals to provide to patients:

  • contact your doctor straight away if you experience itching, skin blistering, peeling or sores, or ulcers in the mouth or in lining of nose, throat or genital area
  • always read the leaflet that accompanies your medicines and talk to your doctor, nurse, or pharmacist if you are concerned about any side effects

Review of atezolizumab and SCARs

Atezolizumab (Tecentriq▼) is an immune-stimulatory drug indicated for cancers including those of the bladder, lung, and liver – see product information for full indications.

Severe cutaneous adverse reactions (SCARs) were previously known to be potentially associated with the use of atezolizumab. Based on evidence from a recent analysis (see detailed cases in next section), SCARs are now considered to be an identified risk for atezolizumab. The product information, including the Patient Information Leaflet, has been updated to include information about these reactions and a letter sent to prescribers of this medicine.

Although review of the cases worldwide found no reports of SCARs for patients on atezolizumab with a history of these reactions with another immune-stimulatory drug, healthcare professionals are advised to carefully consider the use of atezolizumab in patients who have had a severe or life-threatening SCAR following treatment with an immune-stimulatory anti-cancer drug.

Details of cases reported with atezolizumab

A review of safety data for atezolizumab and risk of SCARs was recently completed in Europe. As of 31 July 2020, a cumulative analysis of the company’s safety database identified 99 cases of SCARs worldwide (97 of which were serious). Of the 99 cases, the majority (48%) were reported from clinical studies, with 30% from post-marketing settings. Approximately 23,654 clinical trial patients and 106,316 patients in post-marketing settings worldwide have been exposed to atezolizumab as of 17 May 2020. [footnote 1]

Of the 99 cases, 35 cases were identified as erythema multiforme, 25 cases as Stevens-Johnsons syndrome (SJS), 12 cases as a toxic skin eruption, 8 cases as toxic epidermal necrolysis (TEN), 7 cases as dermatitis bullous, 6 cases as dermatitis exfoliative generalised, 4 cases as drug reaction with eosinophilia and systemic symptoms (DRESS), and 2 cases as skin necrosis.

Of the 99 cases of SCARs, 36 were confirmed by histopathology or specialist diagnosis. Of which, 5 cases were considered to be of likely causality and 20 cases were possibly temporally related to multiple suspect medications including atezolizumab.

In the majority of cases (55 of 99), the outcome was reported as recovered, in 21 cases the patients were recovering, and in 14 cases the patients had not recovered. One elderly patient who received atezolizumab monotherapy died.

Based on clinical trials and post-marketing data, the most frequently reported range of time to onset was within 1 month after the first dose of atezolizumab (37%; 38 cases). Where reported, atezolizumab treatment was withdrawn or interrupted in 58 cases and the dose was not changed in 16 cases.

The incidence rates of SCARs, regardless of severity, from pooled atezolizumab monotherapy (n=3178) and combination therapy (n=4371) company-sponsored clinical studies was 0.7% and 0.6% respectively.

Risk of SCARs with other immune-stimulatory drugs

Other products used for cancers in the same class as atezolizumab, including cemiplimab, ipilimumab, nivolumab, and pembrolizumab list SCARs (including SJS and TEN) as a possible side effects in the Summary of Product Characteristics (SmPC) with an associated warning and precautions. Avelumab and durvalumab are known to cause other immune-mediated skin adverse reactions. As for the other immune-stimulatory anti-cancer drugs, patients should be monitored for the signs and symptoms of serious skin reactions and treatment withheld or discontinued according to the severity of the event as described in the SmPC for each product.

Since authorisation and up to 13 June 2021, in the UK, Yellow Cards reporting SJS, TEN or DRESS have been received for atezolizumab (n=2), ipilimumab (n=13), nivolumab (n=15), and pembrolizumab (n=9).

In interpreting these data, caution should be exercised and comparisons not drawn between the medicines given different exposures and other factors unrelated to the inherent safety of the medicines that may affect the number of reports. Reporters are asked to submit Yellow Card reports even if they only have a suspicion that the medicine may have caused the adverse drug reaction.

About severe cutaneous adverse reactions (SCARs)

SCARs are a heterogeneous group of delayed hypersensitivity reactions. These events mainly consist of acute generalised exanthematous pustulosis (AGEP), SJS, TEN, and DRESS and can be potentially life-threatening, and lead to severe, potentially chronic sequelae.

Immune-stimulatory anti-cancer drugs

Immune-stimulatory anti-cancer drugs authorised in the UK include: Tecentriq▼(atezolizumab), Bavencio▼ (avelumab), Libtayo▼ (cemiplimab), Imfinzi▼ (durvalumab), Yervoy (ipilimumab), Opdivo (nivolumab), and Keytruda (pembrolizumab).

These medicines are used as monotherapy or combination therapy with other immune-stimulatory drugs or chemotherapeutic drugs and are indicated for a variety of cancers.

Report suspected reactions on a Yellow Card

Please continue to report suspected adverse drug reactions (ADRs) via the Yellow Card website or Yellow Card app (Apple App Store or Google Play Store). All ADRs associated with black triangle medicines should be reported – this will allow quick identification of new safety information.

When reporting please provide as much information as possible, including information about product brand name, batch numbers, medical history, any concomitant medication, onset and, treatment dates.

Report suspected side effects to medicines, vaccines or medical device and diagnostic adverse incidents used in coronavirus (COVID-19) using the dedicated Coronavirus Yellow Card reporting site or the Yellow Card app. See the MHRA website for the latest information on medicines and vaccines for COVID-19.

Article citation: Drug Safety Update volume 14, issue 11: June 2021: 2.

  1. Exposure data used with agreement of Roche, 2021. 

Published 17 June 2021