This phase 1/2a, open-label study (NCT02419417) evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of BMS-986158, a selective bromodomain and extraterminal domain (BET) inhibitor. Dose escalation was performed with 3 BMS-986158 dosing schedules: A (5 days on, 2 days off; range, 0.75–4.5 mg), B (14 days on, 7 days off; 2.0–3.0 mg), and C (7 days on, 14 days off; 2.0–4.5 mg). Eighty-three patients were enrolled and received ≥1 BMS-986158 dose. Diarrhea (43%) and thrombocytopenia (39%) were the most common treatment-related adverse events (TRAEs). A lower incidence of TRAEs was found with schedules A (72%) and C (72%) vs. B (100%). Stable disease was achieved in 12 (26.1%), 3 (37.5%), and 9 (31.0%) patients on schedules A, B, and C, respectively. Two patients on schedule A with a 4.5-mg starting dose (ovarian cancer, n = 1; nuclear protein in testis [NUT] carcinoma, n = 1) experienced a partial response. BMS-986158 demonstrated rapid-to-moderate absorption (median time to maximum observed plasma concentration, 1–4 h). As expected with an epigenetic modifier, expression changes in select BET-regulated genes occurred with BMS-986158 treatment. Schedule A dosing (5 days on, 2 days off) yielded tolerable safety, preliminary antitumor activity, and a dose-proportional PK profile.

The approval of CDK4/6 inhibitors has dramatically improved care for the treatment of HR+/HER2– advanced breast cancer, but navigating the rapidly-expanding treatment evidence base is challenging. In this narrative review, we provide best-practice recommendations for the first-line treatment of HR+/HER2– advanced breast cancer in Canada based on relevant literature, clinical guidelines, and our own clinical experience. Due to statistically significant improvements in overall survival and progression-free survival, ribociclib + aromatase inhibitor is our preferred first-line treatment for de novo advanced disease or relapse ≥12 months after completion of adjuvant endocrine therapy and ribociclib or abemaciclib + fulvestrant is our preferred first-line treatment for patients experiencing early relapse. Abemaciclib or palbociclib may be used when alternatives to ribociclib are needed, and endocrine therapy can be used alone in the case of contraindication to CDK4/6 inhibitors or limited life expectancy. Considerations for special populations—including frail and fit elderly patients, as well as those with visceral disease, brain metastases, and oligometastatic disease—are also explored. For monitoring, we recommend an approach across CDK4/6 inhibitors. For mutational testing, we recommend routinely performing ER/PR/HER2 testing to confirm the subtype of advanced disease at the time of progression and to consider ESR1 and PIK3CA testing for select patients. Where possible, engage a multidisciplinary care team to apply evidence in a patient-centric manner.

Purpose: Treatment options for advanced head and neck squamous cell carcinoma (HNSCC) previously treated with platinum-based chemotherapy and a PD-1 inhibitor are limited. Trophoblast cell-surface antigen 2 (Trop-2) is highly expressed in HNSCC. Sacituzumab govitecan (SG) is a Trop-2–directed antibody-drug conjugate approved for patients with certain previously treated solid tumors. Patients and Methods: TROPiCS-03 (NCT03964727) is an open-label, multicohort, phase II study evaluating SG in advanced solid tumors, including HNSCC. Adults with locally advanced or metastatic HNSCC that progressed following platinum-based chemotherapy and anti–PD-(L)1 therapy [given sequentially (either order) or in combination] were administered SG 10 mg/kg on days 1 and 8 of a 21-day cycle. The primary endpoint was the investigator-assessed objective response rate. Secondary endpoints included duration of response, clinical benefit rate, progression-free survival, overall survival, and safety. Results: Patients (N = 43) received a median of 3 (range, 2–9) prior anticancer regimens. The objective response rate was 16% [95% confidence interval (CI), 7%–31%], with seven confirmed partial responses. The clinical benefit rate was 28% (95% CI, 15%–44%). The median (95% CI) duration of response, progression-free survival, and overall survival were 4.2 (2.6–not reached), 4.1 (2.6–5.8), and 9.0 (7.1–10.5) months, respectively. The most common treatment-emergent adverse events (TEAE) were diarrhea (47%), nausea (47%), and neutropenia (47%). Grade ≥3 TEAE occurred in 58% of patients. Three patients died from TEAE, with one event (septic shock) considered related to SG. Conclusions: These data demonstrate the clinical potential of Trop-2–directed therapy in managing heavily pretreated patients with advanced HNSCC.

Purpose: Endocrine-based therapy is the initial primary treatment option for hormone receptor–positive and human epidermal growth factor receptor 2-negative (HR+/HER2−) metastatic breast cancer (mBC). However, patients eventually experience disease progression due to resistance to endocrine therapy. Molibresib (GSK525762) is a small-molecule inhibitor of bromodomain and extraterminal (BET) family proteins (BRD2, BRD3, BRD4, and BRDT). Preclinical data suggested that the combination of molibresib with endocrine therapy might overcome endocrine resistance. This study aimed to investigate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy [objective response rate (ORR)] of molibresib combined with fulvestrant in women with HR+/HER2− mBC. Patients and Methods: In this phase I/II dose-escalation and dose-expansion study, patients received oral molibresib 60 or 80 mg once daily in combination with intramuscular fulvestrant. Patients enrolled had relapsed/refractory, advanced/metastatic HR+/HER2− breast cancer with disease progression on prior treatment with an aromatase inhibitor, with or without a cyclin-dependent kinase 4/6 inhibitor. Results: The study included 123 patients. The most common treatment-related adverse events (AE) were nausea (52%), dysgeusia (49%), and fatigue (45%). At a 60-mg dosage of molibresib, >90% of patients experienced treatment-related AE. Grade 3 or 4 treatment-related AE were observed in 47% and 48% of patients treated with molibresib 60 mg and molibresib 80 mg, respectively. The ORR was 13% [95% confidence interval (CI), 8–20], not meeting the 25% threshold for proceeding to phase II. Among 82 patients with detected circulating tumor DNA and clinical outcome at study enrollment, a strong association was observed between the detection of copy-number amplification and poor progression-free survival (HR, 2.89; 95% CI, 1.73–4.83; P < 0.0001). Conclusions: Molibresib in combination with fulvestrant did not demonstrate clinically meaningful activity in this study.

Purpose: Growth and differentiation factor 15 (GDF15) is overexpressed in multiple solid tumors and is thought to exert immunosuppressive effects in the tumor microenvironment. AZD8853 is an anti-GDF15 mAb. Patients and Methods: This first-in-human, phase I/IIa, open-label study (NCT05397171) assessed AZD8853 monotherapy in previously treated patients with advanced/metastatic microsatellite-stable colorectal cancer and urothelial carcinoma. The primary objective was safety including dose-limiting toxicities. Secondary objectives included efficacy, pharmacokinetics, and pharmacodynamics (PD), including free serum GDF15. Exploratory objectives included biomarkers of clinical activity and effects on cancer cachexia. Results: During dose escalation, 16 patients received AZD8853 300 mg (n = 3), 1,000 mg (n = 6), or 3,000 mg (n = 7) intravenously every 3 weeks; 15 patients had microsatellite-stable colorectal cancer; and one patient had urothelial carcinoma. By June 6, 2023, all patients had discontinued treatment. Thirteen (81.3%) patients had treatment-emergent adverse events (TEAE); most commonly diarrhea (31.3%), abdominal pain (31.3%), and decreased appetite (25%). Eight (50.0%) patients had grade ≥3 TEAEs, and six (37.5%) had serious TEAEs, none treatment related. There were no dose-limiting toxicities. The best response per RECIST v1.1 was stable disease in five (31.3%) patients and disease progression in 11 (68.8%) patients. AZD8853 showed linear pharmacokinetics with a half-life of 5 to 10 days, supporting every 3 weeks dosing. AZD8853 suppression of GDF15 was transient. There was no evidence of ctDNA clearance or dose-dependent changes in peripheral T cells. Changes in body weight showed no apparent trends. Conclusions: AZD8853 was well tolerated; however, no objective responses or PD effects were seen, and GDF15 suppression was not sustained. The study was terminated after dose escalation. Significance: GDF15 is upregulated in the tumor microenvironment and suppresses antitumor immune responses. In this first-in-human trial, the anti-GDF15 antibody AZD8853 was well tolerated in previously treated patients with advanced/metastatic solid tumors, but no objective responses or PD effects were seen and GDF15 suppression was not sustained.

Follow-up care of early breast cancer (EBC) patients usually includes routinely scheduled physical examinations. While ASCO guidelines recommend a physical exam every three to six months for the first three years, little evidence supports this schedule. We evaluated recurrence detection of patients transferred into a single centre survivorship program that follows ASCO recommendations. Patients with EBC referred to the Wellness Beyond Cancer Program (WBCP) who had breast cancer recurrence between February 1, 2013, and January 1, 2019 were reviewed. Descriptive analyses were used to present patient and disease characteristics stratified by type of recurrence and mode of cancer detection. Of 206 recurrences, 135 were distant recurrences (65.5%), 41 were ipsilateral breast recurrences (19.9%), and 30 were contralateral breast primaries (14.6%). Distant recurrences were primarily detected via patient-reported symptoms (125/135, 92.6%). 53.7% (22/41) of ipsilateral breast recurrences were detected by patients and 41.5% (17/41) by routine imaging. Contralateral breast primaries were primarily detected by imaging 83.3% (25/30) and patient-reported symptoms 16.7% (5/30). Only 2/206 (1.14%) recurrences/new primaries were detected by healthcare providers at routinely scheduled follow-up visits. Despite following ASCO guidelines, healthcare providers rarely detect recurrences at routinely scheduled follow-up appointments. Our data suggests that approximately 35, 000 follow-up visits were required for healthcare providers to detect these 2 recurrences. While reduced in-person visits may affect other aspects of follow-up care (e.g. toxicity management), it appears unlikely, provided patients attend regular screening tests, that less frequent in-person follow-up is associated with worse breast cancer-related outcomes.