NEJM original articles

Background. Patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer and residual disease after neoadjuvant therapy are at high risk for recurrence.

Methods. In a phase 3, open-label, international, randomized trial, we investigated postneoadjuvant trastuzumab deruxtecan (T-DXd; 5.4 mg per kilogram of body weight) as compared with trastuzumab emtansine (T-DM1; 3.6 mg per kilogram), the current standard treatment, in patients with HER2-positive breast cancer with residual invasive disease and node-positive disease at surgery or inoperable disease at diagnosis. The primary end point was invasive disease-free survival, and the key secondary end point was disease-free survival (including survival free from noninvasive breast cancers and second primary nonbreast cancers). Other end points included overall survival, distant recurrence-free interval, brain metastasis-free interval, and safety.

Results. A total of 1635 patients were randomly assigned (in a 1:1 ratio) to receive T-DXd (818 patients) or T-DM1 (817 patients). At the data-cutoff date, the median duration of follow-up was approximately 30 months in each group. Invasive-disease events or deaths were reported in 51 patients (6.2%) in the T-DXd group and 102 patients (12.5%) in the T-DM1 group (hazard ratio, 0.47; 95% confidence interval [CI], 0.34 to 0.66; P<0.001); 3-year invasive disease-free survival was 92.4% and 83.7%, respectively. Invasive-disease events, noninvasive-disease events, or deaths were reported in 52 patients (6.4%) in the T-DXd group and 103 patients (12.6%) in the T-DM1 group (hazard ratio, 0.47; 95% CI, 0.34 to 0.66; P<0.001); 3-year disease-free survival was 92.3% and 83.5%, respectively. The most common adverse events were nausea (71.3% of patients), constipation (32.0%), decreased neutrophil count (31.6%), and vomiting (31.0%) with T-DXd and increased liver-enzyme levels (aspartate aminotransferase [50.2%] and alanine aminotransferase [45.3%]) and decreased platelet count (49.8%) with T-DM1. The incidence of adjudicated drug-related interstitial lung disease was higher with T-DXd than with T-DM1 (9.6% vs. 1.6%). Two patients with interstitial lung disease in the T-DXd group died.

Conclusions. In patients with high-risk, residual invasive HER2-positive breast cancer, postneoadjuvant T-DXd resulted in a significantly higher likelihood of invasive disease-free survival than T-DM1; toxic effects were mainly gastrointestinal and hematologic. An important identified risk of T-DXd is interstitial lung disease, which requires appropriate monitoring and management. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast05 ClinicalTrials.gov number, NCT04622319.).

Background. Randomized trials of long-acting injectable antiretroviral therapy (ART) in persons with human immunodeficiency virus (HIV) who face challenges with adherence to oral medication are lacking.

Methods. We conducted an open-label, randomized trial involving persons with HIV who had inadequate adherence to ART (a persistent HIV-1 RNA level of >200 copies per milliliter or loss to follow-up). Participants received up to 24 weeks of adherence support, conditional economic incentives, and standard care with oral ART (step 1). Participants who had an HIV-1 RNA level of 200 copies per milliliter or lower in step 1 were randomly assigned in a 1:1 ratio to either continue standard care or switch to monthly injections of long-acting cabotegravir plus rilpivirine with or without oral lead-in therapy (step 2). The primary outcome was regimen failure, defined as confirmed virologic failure (two consecutive HIV-1 RNA measurements of >200 copies per milliliter) or treatment discontinuation during step 2.

Results. In step 1 of the trial, we enrolled 453 participants; the median age was 40 years, 63% were Black, and 29% had been assigned female sex at birth. In step 2, a total of 306 participants underwent randomization; 152 were assigned to receive cabotegravir-rilpivirine and 154 to receive standard care. Step 2 randomization was stopped early on the basis of the superiority of cabotegravir-rilpivirine to standard care in secondary outcomes at a prespecified analysis performed after a median follow-up of 48 weeks. The cumulative incidence of regimen failure by week 48 was 22.8% in the cabotegravir-rilpivirine group and 41.2% in the standard-care group (difference, -18.4 percentage points; 98.4% confidence interval [CI], -32.4 to -4.3; P = 0.002). The cumulative incidence of an adverse event was 43.5% in the cabotegravir-rilpivirine group and 42.4% in the standard-care group (difference, 1.1 percentage points; 95% CI, -12.7 to 15.0). Resistance-associated mutations developed in 2 participants with confirmed virologic failure in each group.

Conclusions. Monthly injections of long-acting cabotegravir-rilpivirine were superior to standard oral ART in reducing the risk of regimen failure among persons with HIV who had adherence challenges. (Funded by the National Institute of Allergy and Infectious Diseases; LATITUDE ClinicalTrials.gov number, NCT03635788.).

Background. Rezatapopt is an investigational, first-in-class, oral, selective p53 reactivator that specifically binds to Y220C-mutated p53, which stabilizes p53 in its wild-type conformation and restores its functionality.

Methods. In this phase 1, single-group, dose-escalation and dose-optimization study, we assigned heavily pretreated patients with locally advanced or metastatic solid tumors harboring a TP53 Y220C mutation to receive rezatapopt during continuous 21-day treatment cycles. The primary objectives were to determine the maximum tolerated dose and recommended phase 2 dose. Primary end points included dose-limiting toxic effects and adverse events. Secondary end points included preliminary efficacy and pharmacokinetic features.

Results. A total of 77 patients received rezatapopt at one of eight escalating doses: 150 mg, 300 mg, 600 mg, 1150 mg, 1500 mg, 2000 mg, or 2500 mg once daily or 1500 mg twice daily. The maximum tolerated dose was 1500 mg twice daily. On the basis of safety, efficacy, and pharmacokinetic data, 2000 mg once daily with food was selected as the recommended phase 2 dose. During the treatment period, 76 patients (99%) had at least one adverse event and 29 (38%) had an adverse event of grade 1 or 2. The most common adverse events were nausea (in 58% of patients), vomiting (in 44%), an increased blood creatinine level (in 39%), fatigue (in 39%), and anemia (in 36%). Treatment-related adverse events occurred in 67 patients (87%) and those of grade 1 or 2 in 48 (62%); 2 patients (3%) discontinued rezatapopt because of a treatment-related adverse event. Most gastrointestinal adverse events resolved with the treatment of symptoms and were less frequent when rezatapopt was given with food. Anemia was the most common adverse event of grade 3 or higher during the treatment period, occurring in 16% of patients. The overall response (complete or partial response) was 20% among all patients and 30% among those who had a KRAS wild-type tumor and received a dose of at least 1150 mg once daily. Confirmed responses were seen across multiple tumor types, including ovarian and breast cancers. All patients with a response had a solid tumor that harbored TP53 Y220C and wild-type KRAS.

Conclusions. In this phase 1 study involving heavily pretreated patients, the most common adverse events associated with rezatapopt were nausea and vomiting. Antitumor activity occurred across multiple tumor types, providing proof of concept for p53 reactivation. (Funded by PMV Pharmaceuticals; PYNNACLE ClinicalTrials.gov number, NCT04585750.).

Background. Tecovirimat is approved for smallpox treatment under the Food and Drug Administration Animal Rule on the basis of efficacy in nonhuman primate models of mpox (previously known as monkeypox). However, the clinical efficacy of tecovirimat against human clade II mpox is unclear.

Methods. In a phase 3, international, double-blind, randomized, placebo-controlled trial, we evaluated the efficacy of oral tecovirimat in adults with laboratory-confirmed clade II mpox. Participants were randomly assigned in a 2:1 ratio to receive tecovirimat or placebo for 14 days. The primary outcome was clinical resolution, assessed in a time-to-event analysis in participants with active skin or mucosal lesions. Secondary outcomes included reduction in pain, assessed in all participants with laboratory-confirmed mpox and in those with severe pain at baseline (pain score, 7 to 10; scale, 0 [no pain] to 10 [worst pain imaginable]); complete lesion healing (assessed in a time-to-event analysis); viral DNA clearance; and safety.

Results. Of 412 participants who underwent randomization (275 to tecovirimat and 137 to placebo), 344 had laboratory-confirmed mpox, and 336 had active skin or mucosal lesions and were included in the primary analysis. By day 29, the estimated cumulative incidence of clinical resolution was 83% with tecovirimat and 84% with placebo; the competing-risks hazard ratio for clinical resolution was 0.98 (95% confidence interval [CI], 0.74 to 1.31; P = 0.89). No substantial between-group differences were seen in pain reduction among participants with severe pain (difference, 0.1 point; 95% CI, -0.8 to 1.0), in complete lesion healing (competing-risks hazard ratio, 0.97; 95% CI, 0.75 to 1.26), or in viral DNA clearance. The incidence of adverse events of grade 3 or higher was similar in the two groups (4% with tecovirimat and 3% with placebo).

Conclusions. This trial showed no evidence that tecovirimat therapy shortened the time to clinical resolution, reduced pain, or increased viral clearance among adults with clade II mpox. (Funded by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health; STOMP/A5418 ClinicalTrials.gov number, NCT05534984.).