NEJM original articles

Background. Among patients with mismatch repair-deficient (dMMR), locally advanced rectal cancer, neoadjuvant checkpoint blockade eliminated the need for surgery in a high proportion of patients. Whether this approach can be extended to all early-stage dMMR solid tumors, regardless of tumor site, is unknown.

Methods. We conducted a phase 2 study in which patients with stage I, II, or III dMMR solid tumors that were amenable to curative-intent surgery were treated with neoadjuvant dostarlimab, a programmed cell death 1 (PD-1) blocking agent, for 6 months. The response to treatment was assessed in two cohorts: patients in cohort 1 had dMMR, locally advanced rectal cancer, and patients in cohort 2 had dMMR nonrectal solid tumors. Patients with a clinical complete response could elect to proceed with nonoperative management; those with residual disease were to undergo resection. In this analysis, the primary end point, assessed in cohort 1, was a sustained clinical complete response at 12 months. Recurrence-free survival and safety were evaluated.

Results. A total of 117 patients were included in the analysis. In cohort 1, all 49 patients who completed treatment had a clinical complete response and elected to proceed with nonoperative management. A total of 37 patients had a sustained clinical complete response at 12 months, a finding that met the criterion for efficacy. In cohort 2, a total of 35 of 54 patients who completed treatment had a clinical complete response, and 33 elected to proceed with nonoperative management. Among the 103 patients who completed treatment across both cohorts, 84 had a clinical complete response, and 82 did not undergo surgery. Among the 117 total patients, recurrence-free survival at 2 years was 92% (95% confidence interval, 86 to 99); the median follow-up for recurrence was 20.0 months (range, 0 to 60.8). The majority of patients (95%) had reversible, grade 1 or 2 adverse events (60%) or had no adverse events (35%). The option for curative resection was not compromised during or after treatment in any of the patients.

Conclusions. Among patients with early-stage dMMR solid tumors that were amenable to curative-intent surgery, neoadjuvant PD-1 blockade led to organ preservation in a high proportion of patients. (Funded by Swim Across America and others; ClinicalTrials.gov number, NCT04165772.).

Background. Autoimmune generalized myasthenia gravis is a disease that manifests with fluctuating muscle weakness. Inebilizumab is a monoclonal antibody that depletes CD19+ B cells, which are central to disease pathogenesis.

Methods. In this phase 3, double-blind, randomized, placebo-controlled trial, we enrolled participants with myasthenia gravis who had anti-acetylcholine receptor antibodies or anti-muscle-specific kinase antibodies. Participants were randomly assigned, in a 1:1 ratio, to receive intravenous inebilizumab (300 mg administered on days 1 and 15 for all, and additionally on day 183 for participants who were acetylcholine receptor antibody-positive) or matching placebo for 52 weeks (in participants who were acetylcholine receptor antibody-positive) or 26 weeks (in those who were muscle-specific kinase antibody-positive). Glucocorticoid therapy was tapered, starting at week 4, to a target of 5 mg per day by week 24. The primary end point was the change from baseline in the score on the Myasthenia Gravis Activities of Daily Living scale (MG-ADL; scores range from 0 to 24, with higher scores indicating greater disease activity) at week 26 in the combined acetylcholine receptor antibody-positive and muscle-specific kinase antibody-positive trial populations. A key secondary end point was the change from baseline in the score on the Quantitative Myasthenia Gravis scale (QMG; scores range from 0 to 39, with higher scores indicating greater disease activity) at week 26 in the combined population. Safety was assessed.

Results. A total of 238 participants underwent randomization (119 per group). Participants who received inebilizumab had a greater reduction in the MG-ADL score than those who received placebo (least-squares mean change, -4.2 vs. -2.2; adjusted difference, -1.9; 95% confidence interval [CI], -2.9 to -1.0; P<0.001) at week 26. Participants who received inebilizumab had a greater reduction in the QMG score than those who received placebo (least-squares mean change, -4.8 vs. -2.3; adjusted difference, -2.5; 95% CI, -3.8 to -1.2; P<0.001). The most common adverse events with inebilizumab were headache, cough, nasopharyngitis, infusion-related reactions, and urinary tract infections. Inebilizumab was not associated with a higher incidence of serious adverse events.

Conclusions. In participants with acetylcholine receptor antibody-positive or muscle-specific kinase antibody-positive generalized myasthenia gravis, inebilizumab improved function and reduced disease severity. (Funded by Amgen; MINT ClinicalTrial.gov number, NCT04524273.).

Background. Innovative oral targeted therapies are warranted for patients with human epidermal growth factor receptor 2 (HER2)-mutant non-small-cell lung cancer (NSCLC). Zongertinib is an oral, irreversible, HER2-selective tyrosine kinase inhibitor that has been shown to have efficacy in persons with advanced or metastatic solid tumors with HER2 alterations in a phase 1 study.

Methods. We evaluated zongertinib in a multicohort, phase 1a-1b trial involving patients with advanced or metastatic HER2-mutant NSCLC. Here we report the primary analysis of zongertinib in previously treated patients: those with tumors harboring a mutation in the tyrosine kinase domain (cohort 1), those with tumors harboring a mutation in the tyrosine kinase domain previously treated with a HER2-directed antibody-drug conjugate (cohort 5), and those with tumors harboring a non-tyrosine kinase domain mutation (cohort 3). In cohort 1, patients were initially randomly assigned to receive zongertinib at a dose of 120 mg or 240 mg once daily. Patients in cohorts 5 and 3 initially received 240 mg daily. After an interim analysis of data from cohort 1, subsequently recruited patients across all cohorts received zongertinib at a dose of 120 mg. The primary end point was an objective response assessed by blinded independent central review (cohorts 1 and 5) or by investigator review (cohort 3). Secondary end points included the duration of response and progression-free survival.

Results. In cohort 1, a total of 75 patients received zongertinib at a dose of 120 mg. At the data cutoff (November 29, 2024), 71% of these patients (95% confidence interval [CI], 60 to 80; P<0.001 against a ≤30% benchmark) had a confirmed objective response; the median duration of response was 14.1 months (95% CI, 6.9 to not evaluable), and the median progression-free survival was 12.4 months (95% CI, 8.2 to not evaluable). Grade 3 or higher drug-related adverse events occurred in 13 patients (17%). In cohort 5 (31 patients), 48% of the patients (95% CI, 32 to 65) had a confirmed objective response. Grade 3 or higher drug-related adverse events occurred in 1 patient (3%). In cohort 3 (20 patients), 30% of the patients (95% CI, 15 to 52) had a confirmed objective response. Grade 3 or higher drug-related adverse events occurred in 5 patients (25%). Across all three cohorts, no cases of drug-related interstitial lung disease occurred.

Conclusions. Zongertinib showed clinical benefit with mainly low-grade adverse events in patients with previously treated HER2-mutant NSCLC. (Funded by Boehringer Ingelheim; Beamion LUNG-1 ClinicalTrials.gov number, NCT04886804.).

Background. A surge of cases of Corynebacterium diphtheriae infection was observed in reception centers for migrants in Europe beginning in the summer of 2022. Most of the cases were cutaneous, although some respiratory cases as well as one death were reported. A pan-European consortium was created to assess the clinical, epidemiologic, and microbiologic features of this outbreak.

Methods. We assessed cases of toxigenic C. diphtheriae infection that were reported in 10 European countries from January through November 2022. Data regarding countries of origin and transit routes were obtained from interviews with the patients. Whole-genome sequencing and antimicrobial-susceptibility testing were performed on bacterial isolates that were obtained from the patients. The phylogenetic relationships of the isolates and their antimicrobial-resistance genes were evaluated.

Results. A total of 363 toxigenic C. diphtheriae isolates were identified among 362 patients during the study period. Clinical data were available for 346 patients (95.6%): 268 (77.5%) had cutaneous diphtheria, 53 (15.3%) had respiratory diphtheria (11 [3.2%] had a pseudomembrane), and 9 (2.6%) had both respiratory and cutaneous symptoms. Four major genetic clusters were identified, which indicated the multiclonal nature of the outbreak. The ermX gene (which codes for erythromycin resistance) and the pbp2m and blaOXA-2 genes (which code for beta-lactam resistance) were detected in a subgroup of isolates. Isolates that carried ermX were resistant to erythromycin, and isolates that carried pbp2m were resistant to penicillin but were susceptible to amoxicillin. On the basis of the genomic variation within the four genetic clusters, their most recent common ancestors were estimated to have existed between 2017 and 2020.

Conclusions. The distribution of each genetic cluster of C. diphtheriae isolates across multiple countries in Europe showed repeated cross-border spread. The large number of C. diphtheriae infections among migrants is a cause for concern, particularly given that antimicrobial-resistance phenotypes threaten the efficacy of first-line treatments. (Funded by the Bavarian State Ministry of Health, Care, and Prevention and others.).

Background. Hereditary leiomyomatosis and renal-cell cancer (HLRCC) is an inherited disorder characterized by germline pathogenic variants in the gene encoding fumarate hydratase and an increased risk of papillary renal-cell carcinoma. No effective therapy is known for patients with advanced HLRCC-associated papillary renal-cell carcinoma, and most patients die from progressive disease.

Methods. In this open-label, phase 2 study, we evaluated the efficacy of bevacizumab (10 mg per kilogram of body weight every 2 weeks) and erlotinib (150 mg once daily) in patients with advanced HLRCC-associated or sporadic papillary renal-cell carcinoma. The primary end point was overall response; secondary end points included progression-free and overall survival.

Results. A total of 43 patients with HLRCC-associated papillary renal-cell carcinoma and 40 patients with sporadic papillary renal-cell carcinoma were enrolled. A confirmed response occurred in 31 patients (72%; 95% confidence interval [CI], 57 to 83) with HLRCC-associated papillary renal-cell carcinoma; the median progression-free survival was 21.1 months (95% CI, 15.6 to 26.6), and the median overall survival was 44.6 months (95% CI, 32.7 to could not be estimated). A confirmed response occurred in 14 patients (35%; 95% CI, 22 to 51) with sporadic papillary renal-cell carcinoma, with a median progression-free survival of 8.9 months (95% CI, 5.5 to 18.3) and a median overall survival of 18.2 months (95% CI, 12.6 to 29.3). The most common treatment-related adverse events were acneiform rash (93%), diarrhea (89%), and proteinuria (78%). The most common treatment-related adverse events of grade 3 or higher were hypertension (34%) and proteinuria (17%).

Conclusions. The combination of bevacizumab and erlotinib showed antitumor activity in patients with HLRCC-associated or sporadic papillary renal-cell carcinoma. Toxic effects were those known to be associated with this combination. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT01130519.).