A phase 1 trial of the MEK inhibitor selumetinib in combination with pembrolizumab for advanced or metastatic solid tumors.

MEK inhibitors have immunomodulatory activity and potential for synergistic activity when combined with PD-1 inhibitors. We evaluated selumetinib (inhibitor of MEK1/2) plus pembrolizumab (anti‒PD-1 antibody) in patients with advanced/metastatic solid tumors. In this phase 1b study, adults with previously treated advanced/metastatic solid tumors received pembrolizumab 200 mg intravenously every 3 weeks plus selumetinib on days 1‒14 per 3-week cycle (2 weeks on/1 week off); selumetinib dosing began at 50 mg orally twice daily with escalation in 25 mg increments for ≤ 35 cycles. Primary endpoints were dose-limiting toxicities (DLTs), adverse events (AEs), and treatment discontinuations due to AEs. Thirty-two patients were enrolled. Dose escalation was completed up to selumetinib 125 mg twice daily. The target DLT rate of 30% was not reached at any dose level. In the selumetinib 100 mg group, 2/11 patients (18.2%) experienced DLTs (n = 1 grade 3 diarrhea, n = 1 grade 3 fatigue). In the selumetinib 125 mg group, 3/14 (21.4%) experienced DLTs (n = 1 grade 2 retinal detachment, n = 1 grade 3 retinopathy, n = 1 grade 3 stomatitis). Dose-related changes in pharmacokinetic exposures were observed for selumetinib and N-desmethyl selumetinib up to 100 mg (saturation at 125 mg). Two patients achieved partial responses (1 each with selumetinib 75 mg and 125 mg) for an objective response rate of 6%. The study was stopped early because of insufficient efficacy. Although the target DLT rate was not reached at any dose level and no new safety signals were identified, selumetinib plus pembrolizumab had limited antitumor activity in this population. Trial registration: ClinicalTrials.gov , NCT03833427.

Facilities that service economically advantaged neighborhoods perform surgical metastasectomy more often for patients with colorectal liver metastases.

BACKGROUND: Metastasectomy of isolated colorectal liver metastases (CRLM) requires significant clinical expertise and may not be readily available or offered. The authors hypothesized that hospitals that treat a greater percentage of patients from higher income catchment areas are more likely to perform metastasectomies regardless of patient or tumor characteristics. METHODS: Using the National Cancer Data Base, the authors classified facilities into facility income quartiles (FIQs) based on the percentage of patients from the wealthiest neighborhoods (by zip code). Quartile 1 included facilities with <2.1% of the patients residing within the highest income zip codes, quartile 2 included facilities with 2.2% to 15.6% of patients residing within the highest income zip codes, quartile 3 included facilities with 15.7% to 40.2% of patients residing within the highest income zip codes, and quartile 4 included facilities with 40.3% to 90.5% of patients residing within the highest income ZIP codes. Patient, tumor, and facility characteristics were analyzed using a multivariate logistic regression to identify associations between metastasectomy and FIQ. RESULTS: Patients with CRLM were more likely to undergo metastasectomy at facilities in the highest FIQ compared with the lowest FIQ (18% vs 11% in FIQ4; P = .001). This trend was not observed in the resection of primary tumors for nonmetastatic CRLM (rates of 95% vs 93%; P = .94). After adjusting for individual insurance status, distance traveled, zip code-level individual income, tumor, and host, patients who were treated at the highest FIQ facilities were found to be more likely to undergo metastasectomy (odds ratio, 1.29; 95% CI, 1.02-1.72 [P = .03]). CONCLUSIONS: Metastasectomy for CRLM is more likely to occur at facilities that serve a greater percentage of patients from high-income catchment areas, regardless of individual patient characteristics. This disparity uniquely affects those patients with advanced cancers for which specialized expertise for therapy is necessary.

A UGT1A1 genotype-guided dosing study of modified FOLFIRINOX in previously untreated patients with advanced gastrointestinal malignancies.

BACKGROUND: FOLFIRINOX (5-fluorouracil [5-FU], leucovorin, irinotecan, oxaliplatin) is an effective but toxic therapy for pancreatic cancer. UGT1A1 (UDP glucuronosyltransferase 1A1) eliminates the active metabolite of irinotecan. Polymorphisms reduce UGT1A1 activity, leading to toxicity. The primary objective was to determine the dose-limiting toxicity (DLT) rate in cycle 1 of modified FOLFIRINOX (mFOLFIRINOX) using genotype-guided dosing of irinotecan for the most common UGT1A1 genotypes (*1/*1, *1/*28) in advanced gastrointestinal malignancies, with expansion in pancreatic and biliary tract cancers. METHOD: 5-FU (2400 mg/m2 over 46 hours), leucovorin (400 mg/m2 ), oxaliplatin (85 mg/m2 ), and irinotecan were given every 14 days. Irinotecan doses of 180, 135, and 90 mg/m2 were administered for UGT1A1 genotypes *1/*1, *1/*28, and *28/*28, respectively. Prophylactic pegfilgrastim was omitted in cycle 1 for cohort 1 (tolerability by genotype), but was given in cohort 2 (tolerability by tumor type). Doses were tolerable if the upper limit of a 2-sided 80% confidence interval for DLT rate was ≤33%. RESULTS: In cohort 1, DLTs (most commonly febrile neutropenia, fatigue, diarrhea) occurred in 2/15 (13%), 3/16 (19%), and 4/10 (40%) patients with *1/*1, *1/*28, and *28/*28 genotypes, respectively. In cohort 2, 6/19 (32%) pancreatic and 4/19 (21%) biliary tract cancer patients experienced DLTs (most commonly fatigue, diarrhea, nausea/vomiting). In cohort 2, upper confidence limits of DLT rates exceeded 33%. Response rates were 38% in pancreatic and 21% in biliary tract cancers. CONCLUSION: On the basis of our prespecified criteria, tolerability of UGT1A1 genotype-guided mFOLFIRINOX was not established in pancreatic and biliary tract cancers. However, this regimen was effective.

A Phase Ib, Open-Label Study of Dalantercept, an Activin Receptor-Like Kinase 1 Ligand Trap, plus Sorafenib in Advanced Hepatocellular Carcinoma.

LESSONS LEARNED: Patients with hepatocellular carcinoma (HCC) often have limited therapeutic responses to the vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor sorafenib, which is standard of care in advanced HCC. Targeting the activin receptor-like kinase 1 (ALK1) and VEGF pathways simultaneously by combining the ALK1 ligand trap dalantercept with sorafenib may result in more effective angiogenic blockade and delay tumor progression in patients with advanced HCC.Although the combination was generally well tolerated, there was no additive antitumor activity with the combination of dalantercept plus sorafenib in patients with advanced HCC. No complete or partial responses were observed, and overall survival ranged from 1.9 to 23.3 months.These results suggest that, in this patient population, further development of the possible limited benefits of combination therapy with dalantercept plus sorafenib is not warranted. BACKGROUND: Targeting the activin receptor-like kinase 1 (ALK1) and vascular endothelial growth factor (VEGF) pathways may result in more effective angiogenic blockade in patients with hepatocellular carcinoma (HCC). METHODS: In this phase Ib study, patients with advanced HCC were enrolled to dose-escalation cohorts, starting at 0.6 mg/kg dalantercept subcutaneously every 3 weeks plus 400 mg sorafenib orally once daily, or to a dose expansion cohort. The primary objective was to determine the safety and tolerability and the dalantercept maximum tolerated dose (MTD) level. Secondary objectives were to assess the preliminary activity and the association of pharmacodynamic biomarkers with tumor response. RESULTS: A total of 21 patients were enrolled in the study. Five patients received 0.6 mg/kg dalantercept in the first dose escalation cohort. Based on the initial safety results, the dose level was de-escalated to 0.4 mg/kg in the second cohort (n = 6). The MTD was identified as 0.4 mg/kg and used for the dose expansion cohort (n = 10). At this dose level, the combination was generally well tolerated. Overall survival ranged from 1.9 to 23.3 months, and the best overall response was stable disease. CONCLUSION: The addition of dalantercept to sorafenib did not improve antitumor activity in patients with HCC. The dalantercept program in this population was discontinued.

Phase I study of lurbinectedin, a synthetic tetrahydroisoquinoline that inhibits activated transcription, induces DNA single- and double-strand breaks, on a weekly × 2 every-3-week schedule.

Background Lurbinectedin administered as a 1-h intravenous infusion every 3 weeks induces neutropenia, with the nadir usually occurring during the second week. This phase I study evaluated an alternative lurbinectedin dosing schedule consisting of a 1-h infusion on days 1 and 8 every 3 weeks. Patients and methods Twenty-one patients with advanced cancer received lurbinectedin using a standard cohort dose escalation design. Results Three dose levels of 3, 4, and 5 mg of lurbinectedin were explored. The recommended phase II dose was 5 mg, with 3 of 13 patients having dose-limiting toxicity (DLT), although grade 4 neutropenia occurred in 50% of patients. Other frequent toxicities were mild to moderate nausea and vomiting, fatigue, decreased appetite, stomatitis and asymptomatic creatinine and transaminase increases. No objective responses occurred, but prolonged stable disease was observed in 7 patients, including 3 with soft tissue sarcoma. Conclusion The recommended phase II dose of lurbinectedin is 5 mg, administered as a 1-h infusion on days 1 and 8 every 3 weeks. These data support further testing of this dose and schedule, particularly in soft tissue sarcoma.

A Relative Bioavailability, Bioequivalence, and Food Effect Study of Niraparib Tablets in Patients with Advanced Solid Tumors.

PURPOSE: The poly (ADP-ribose) polymerase inhibitor niraparib is indicated as maintenance treatment in patients with certain subtypes of advanced ovarian cancer, and is being investigated in patients with other solid tumors. Niraparib is available in 100-mg capsules with a starting dosage of 200 or 300 mg/d. This study assessed the relative bioavailability (BA) and bioequivalence (BE) between a 1 × 300-mg tablet relative to 3 × 100-mg niraparib capsules. In addition, the food effect (FE) of a high-fat meal on the pharmacokinetic (PK) properties of tablet-formulated niraparib was investigated. METHODS: This was a US-based, 3-stage, open-label, multicenter, single-crossover, randomized-sequence study. Enrolled patients were 18 years and older, with histologically or cytologically confirmed advanced solid tumors (metastatic or local) and disease progression despite standard therapy. Patients were randomly assigned 1:1 to receive niraparib 1 × 300-mg tablet or 3 × 100-mg capsules in the BA and BE stages or 1 × 300-mg tablet in a fasted or fed (high-fat meal) state in the FE stage. Across all study stages, PK parameters were assessed for 7 days after each dose (tablet or capsule) or prandial state (fasted or fed). In the BA stage, patients crossed over to the other treatment after a 7-day washout period, which was extended to 14 days in the BE and FE stages. Tolerability was assessed for patients who received any amount of niraparib. FINDINGS: The BA-, BE-, and FE-evaluable populations comprised 23, 108, and 19 patients, respectively, who completed both treatment periods in each study stage, had sufficient concentration data to accurately estimate PK parameters without niraparib carryover, and did not experience disqualifying events. PK parameters were similar after dosing with tablet or capsule formulations; the 90% CIs of the geometric least square means for Cmax, AUC0-t, and AUC0-∞ were within the 0.80 to 1.25 BE limits. In the FE stage, Cmax, AUC0-t, and AUC0-∞ were 11%, 32%, and 28% higher, respectively, in the fed versus fasted state. The safety population included 29, 168, and 28 patients in the BA, BE, and FE stages, respectively, who received niraparib. No new safety signals were identified. IMPLICATIONS: Niraparib tablets were found to be bioequivalent to capsules. A modest (≤32%) FE was observed with a high-fat meal, but was not considered to be clinically meaningful, given niraparib's PK variability. CLINICALTRIALS: gov identifier: NCT03329001. (Clin Ther. 2024;46:XXX-XXX) © 2024 Elsevier HS Journals, Inc.

Final results of urelumab, an anti-CD137 agonist monoclonal antibody, in combination with cetuximab or nivolumab in patients with advanced solid tumors.

BACKGROUND: Resistance to immune checkpoint inhibitors and targeted treatments for cancer is common; thus, novel immunotherapy agents are needed. Urelumab is a monoclonal antibody agonist that binds to CD137 receptors expressed on T cells. Here, we report two studies that evaluated urelumab in combination with cetuximab or nivolumab in patients with select, advanced solid tumors. METHODS: CA186-018: Patients with metastatic colorectal cancer or metastatic squamous cell carcinoma of the head and neck (SCCHN) were treated in a dose-evaluation phase with urelumab 0.1 mg/kg (urelumab-0.1) every 3 weeks (Q3W)+cetuximab 250 mg/m2 (cetuximab-250) weekly; and in a dose-expansion phase with urelumab 8 mg flat dose (urelumab-8) Q3W+cetuximab-250 weekly. CA186-107: The dose-escalation phase included patients with previously treated advanced solid tumors (or treated or treatment-naive melanoma); patients received urelumab 3 mg flat dose (urelumab-3) or urelumab-8 every 4 weeks+nivolumab 3 mg/kg (nivolumab-3) or 240 mg (nivolumab-240) every 2 weeks. In the expansion phase, patients with melanoma, non-small cell lung cancer, or SCCHN were treated with urelumab-8+nivolumab-240. Primary endpoints were safety and tolerability, and the secondary endpoint included efficacy assessments. RESULTS: CA186-018: 66 patients received study treatment. The most frequent treatment-related adverse events (TRAEs) were fatigue (75%; n=3) with urelumab-0.1+cetuximab-250 and dermatitis (45%; n=28) with urelumab-8+cetuximab-250. Three patients (5%) discontinued due to TRAE(s) (with urelumab-8+cetuximab-250). One patient with SCCHN had a partial response (objective response rate (ORR) 5%, with urelumab-8+cetuximab-250).CA186-107: 134 patients received study treatment. Fatigue was the most common TRAE (32%; n=2 with urelumab-3+nivolumab-3; n=1 with urelumab-8+nivolumab-3; n=40 with urelumab-8+nivolumab-240). Nine patients (7%) discontinued due to TRAE(s) (n=1 with urelumab-3+nivolumab-3; n=8 with urelumab-8+nivolumab-240). Patients with melanoma naive to anti-PD-1 therapy exhibited the highest ORR (49%; n=21 with urelumab-8+nivolumab-240). Intratumoral gene expression in immune-related pathways (CD3, CD8, CXCL9, GZMB) increased on treatment with urelumab+nivolumab. CONCLUSIONS: Although the addition of urelumab at these doses was tolerable, preliminary response rates did not indicate an evident additive benefit. Nevertheless, the positive pharmacodynamics effects observed with urelumab and the high response rate in treatment-naive patients with melanoma warrant further investigation of other anti-CD137 agonist agents for treatment of cancer. TRIAL REGISTRATION NUMBERS: NCT02110082; NCT02253992.

Cobimetinib Plus Vemurafenib in Patients With Solid Tumors With BRAF Mutations: Results From the Targeted Agent and Profiling Utilization Registry Study.

PURPOSE: The Targeted Agent and Profiling Utilization Registry Study is a phase II basket study evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers with genomic alterations known to be drug targets. The results in a cohort of patients with solid tumors with BRAF mutations treated with cobimetinib plus vemurafenib are reported. METHODS: Eligible patients had measurable disease (RECIST v.1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. The primary end point was disease control (DC), defined as complete response (CR) or partial response (PR) or stable disease of at least 16-weeks duration (SD16+). Low-accruing histology-specific cohorts with BRAF mutations treated with cobimetinib plus vemurafenib were collapsed into a single histology-pooled cohort for this analysis. The results were evaluated on the basis of a one-sided exact binomial test with a null DC rate of 15% versus 35% (power, .82; α, .10). The secondary end points were objective response (OR), progression-free survival, overall survival, duration of response, duration of stable disease, and safety. RESULTS: Thirty-one patients with solid tumors with BRAF mutations were enrolled. Twenty-eight patients were evaluable for efficacy. Patients had tumors with BRAF V600E (n = 26), K601E (n = 2), or other (n = 3) mutations. Two patients with CR (breast and ovarian cancers; V600E), 14 with PR (13 V600E, one N581I), and three with SD16+ (two V600E, one T599_V600insT) were observed with a DC rate of 68% (P < .0001; one-sided 90% CI, 54 to 100) and an OR rate of 57% (95% CI, 37 to 76). Nineteen patients experienced ≥one drug-related grade 3-5 adverse event or serious adverse event including one death attributed to treatment-related kidney injury. CONCLUSION: Cobimetinib plus vemurafenib showed antitumor activity in patients with advanced solid tumors with BRAF V600E mutations; additional study is warranted to confirm the antitumor activity in tumors with non-V600E BRAF mutations.

SHP2 Inhibition Sensitizes Diverse Oncogene-Addicted Solid Tumors to Re-treatment with Targeted Therapy.

Rationally targeted therapies have transformed cancer treatment, but many patients develop resistance through bypass signaling pathway activation. PF-07284892 (ARRY-558) is an allosteric SHP2 inhibitor designed to overcome bypass-signaling-mediated resistance when combined with inhibitors of various oncogenic drivers. Activity in this setting was confirmed in diverse tumor models. Patients with ALK fusion-positive lung cancer, BRAFV600E-mutant colorectal cancer, KRASG12D-mutant ovarian cancer, and ROS1 fusion-positive pancreatic cancer who previously developed targeted therapy resistance were treated with PF-07284892 on the first dose level of a first-in-human clinical trial. After progression on PF-07284892 monotherapy, a novel study design allowed the addition of oncogene-directed targeted therapy that had previously failed. Combination therapy led to rapid tumor and circulating tumor DNA (ctDNA) responses and extended the duration of overall clinical benefit. SIGNIFICANCE: PF-07284892-targeted therapy combinations overcame bypass-signaling-mediated resistance in a clinical setting in which neither component was active on its own. This provides proof of concept of the utility of SHP2 inhibitors in overcoming resistance to diverse targeted therapies and provides a paradigm for accelerated testing of novel drug combinations early in clinical development. See related commentary by Hernando-Calvo and Garralda, p. 1762. This article is highlighted in the In This Issue feature, p. 1749.

Dasatinib in previously treated metastatic colorectal cancer: a phase II trial of the University of Chicago Phase II Consortium.

BACKGROUND: Treatment options for metastatic colorectal cancer (CRC) are limited after a fluoropyrimidine, oxaliplatin and irinotecan; novel agents need to be explored in this setting. Dasatinib, an oral inhibitor of Src family kinases, inhibits proliferation in CRC cell lines and has antitumor activity in CRC xenograft models. PATIENTS AND METHODS: We conducted a multi-center phase II trial of dasatinib in unresectable, previously-treated metastatic CRC patients. No more than 2 prior chemotherapy regimens were permitted, which must have contained a fluoropyrimidine, oxaliplatin and irinotecan. The primary endpoint was progression-free survival (PFS) at 4 months. The Simon two-stage design required that at least 5 of the first 19 patients be progression-free at 4 months to expand to a second stage. RESULTS: Nineteen patients enrolled at 9 centers. The study was terminated after the first stage due to lack of efficacy. There were no objective responses; 1 patient (5%) had stable disease for 7.3 months. The PFS rate at 4 months was 5.3% (90% CI: 0.3, 22.6). Median PFS was 1.6 months (90% CI: 1.4, 1.8). Median overall survival was 5.1 months (90% CI: 2.4, 6.3). Grade 3/4 toxicities included fatigue in 16% of patients, and anemia, anorexia, nausea/vomiting and dyspnea in 11%. CONCLUSION: Dasatinib is inactive as a single agent in previously treated metastatic CRC patients.

Overcoming Taxane Resistance: Preclinical and Phase 1 Studies of Relacorilant, a Selective Glucocorticoid Receptor Modulator, with Nab-Paclitaxel in Solid Tumors.

PURPOSE: Chemotherapy resistance remains a major problem in many solid tumors, including breast, ovarian, and pancreatic cancer. Glucocorticoids are one potential driver of chemotherapy resistance as they can mediate tumor progression via induction of cell-survival pathways. We investigated whether combining the selective glucocorticoid receptor (GR) modulator relacorilant with taxanes can enhance antitumor activity. PATIENTS AND METHODS: The effect of relacorilant on paclitaxel efficacy was assessed in OVCAR5 cells in vitro and in the MIA PaCa-2 xenograft. A phase 1 study of patients with advanced solid tumors was conducted to determine the recommended phase 2 dose of relacorilant + nab-paclitaxel. RESULTS: In OVCAR5 cells, relacorilant reversed the deleterious effects of glucocorticoids on paclitaxel efficacy (P < 0.001). Compared with paclitaxel alone, relacorilant + paclitaxel reduced tumor growth and slowed time to progression in xenograft models (both P < 0.0001). In the heavily pretreated phase 1 population [median (range) of prior regimens: 3 (1-8), prior taxane in 75.3% (55/73)], 33% (19/57) of response-evaluable patients achieved durable disease control (≥16 weeks) with relacorilant + nab-paclitaxel and 28.6% (12/42) experienced longer duration of benefit than on prior taxane (up to 6.4×). The most common dose-limiting toxicity of the combination was neutropenia, which was manageable with prophylactic G-CSF. Clinical benefit with relacorilant + nab-paclitaxel was also associated with GR-regulated transcript-level changes in a panel of GR-controlled genes. CONCLUSIONS: The observed preclinical, clinical, and GR-specific pharmacodynamic responses demonstrate that selective GR modulation with relacorilant combined with nab-paclitaxel may promote chemotherapy response and is tolerable. Further evaluation of this combination in tumor types responsive to taxanes is ongoing.

First-in-Human Study of PF-06647020 (Cofetuzumab Pelidotin), an Antibody-Drug Conjugate Targeting Protein Tyrosine Kinase 7, in Advanced Solid Tumors.

PURPOSE: We investigated safety, tolerability, pharmacokinetics, and antitumor activity of the protein tyrosine kinase 7 (PTK7)-targeted, auristatin-based antibody-drug conjugate (ADC) PF-06647020/cofetuzumab pelidotin (NCT02222922). PATIENTS AND METHODS: Patients received PF-06647020 intravenously every 3 weeks at 0.2-3.7 mg/kg or every 2 weeks at 2.1-3.2 mg/kg, in sequential dose escalation, following a modified toxicity probability interval method. In dose expansion, pretreated patients with advanced, platinum-resistant ovarian cancer, non-small cell lung cancer (NSCLC), or triple-negative breast cancer (TNBC) received PF-06647020 2.8 mg/kg every 3 weeks. RESULTS: The most common, treatment-related adverse events for PF-06647020 administered every 3 weeks were nausea, alopecia, fatigue, headache, neutropenia, and vomiting (45%-25%); 25% of patients had grade ≥ 3 neutropenia. Two patients experienced dose-limiting toxicities (grade 3 headache and fatigue) at the highest every 3 weeks dose evaluated. The recommended phase II dose was 2.8 mg/kg every 3 weeks. The overall safety profile observed with PF-06647020 administered every 2 weeks was similar to that of the every 3 weeks regimen. Systemic exposure for the ADC and total antibody generally increased in a dose-proportional manner. Antitumor activity was observed in treated patients with overall objective response rates of 27% in ovarian cancer (n = 63), 19% in NSCLC (n = 31), and 21% in TNBC (n = 29). Responders tended to have moderate or high PTK7 tumor expression by IHC. CONCLUSIONS: This PTK7-targeted ADC demonstrated therapeutic activity in previously treated patients with ovarian cancer, NSCLC, and TNBC at a dose range of 2.1-3.2 mg/kg, supporting further clinical evaluation to refine dose, schedule, and predictive tissue biomarker testing in patients with advanced malignancies.

The Resurgence of Antibody Drug Conjugates in Cancer Therapeutics: Novel Targets and Payloads.

Antibody drug conjugates (ADCs) are an emerging class of therapeutics that consist of a cytotoxic agent linked covalently to an antibody, which is directed toward a specific cell surface target expressed by tumor cells and/or the microenvironment. ADCs leverage the specificity of the antibody such that it functions as a carrier to deliver the cytotoxic payload into the tumor. Four parameters are considered critical for this class of complex engineered therapeutics: target selection, antibody, cytotoxic payload, as well as conjugation and linker technology. The development of this class of drugs has proven more complex than expected. Several challenges have arisen, including a lack of true tumor antigen specificity, early release of the cytotoxic payload into the bloodstream due to linker instability, and low potency of the payload, resulting in either greater toxicity or lack of improved efficacy compared with unconjugated cytotoxics. The approval of trastuzumab emtansine in 2013 for HER2-positive breast cancer served as a proof of concept that ADCs have therapeutic application in solid tumors. Two novel ADCs have recently been approved: trastuzumab deruxtecan for HER2-positive breast cancer and enfortumab vedotin for locally advanced or metastatic urothelial cancer. Trastuzumab deruxtecan is distinguished by a unique biochemical structure with a novel cytotoxic payload, deruxtecan-a highly potent, topoisomerase I inhibitor. Enfortumab vedotin is directed toward nectin-4 and represents an example of successful and strategic target selection. This review focuses on the concepts underlying the choice of suitable targets and novel payloads, discusses specific examples of ADCs in preclinical and clinical development, and provides future directions related to this unique class of therapeutics.

Clinical Assessment of 5-Fluorouracil/Leucovorin, Nab-Paclitaxel, and Irinotecan (FOLFIRABRAX) in Untreated Patients with Gastrointestinal Cancer Using UGT1A1 Genotype-Guided Dosing.

PURPOSE: 5-Fluorouracil (5-FU)/leucovorin, irinotecan, and nab-paclitaxel are all active agents in gastrointestinal cancers; the combination, FOLFIRABRAX, has not been previously evaluated. UDP Glucuronosyltransferase 1A1 (UGT1A1) clears SN-38, the active metabolite of irinotecan. UGT1A1*28 polymorphism reduces UGT1A1 enzymatic activity and predisposes to toxicity. We performed a trial to assess the safety and tolerability of FOLFIRABRAX with UGT1A1 genotype-guided dosing of irinotecan. PATIENTS AND METHODS: Patients with previously untreated, advanced gastrointestinal cancers received FOLFIRABRAX with prophylactic pegfilgrastim every 14 days. UGT1A1 *1/*1, *1/*28, and *28/*28 patients received initial irinotecan doses of 180, 135, and 90 mg/m2, respectively. 5-FU 2,400 mg/m2 over 46 hours, leucovorin 400 mg/m2, and nab-paclitaxel 125 mg/m2 were administered. Doses were deemed tolerable if the dose-limiting toxicity (DLT) rate during cycle 1 was ≤35% in each genotype group. DLTs were monitored using a sequential procedure. RESULTS: Fifty patients enrolled, 30 pancreatic, 9 biliary tract, 6 gastroesophageal, and 5 others. DLTs occurred in 5 of 23 (22%) *1/*1 patients, 1 of 19 (5%) *1/*28 patients, and 0 of 7 *28/*28 patients. DLTs were all grade 3: diarrhea (3 patients), nausea (2 patients), and febrile neutropenia (1 patient). The overall response rate was 31%. Response rates in pancreatic, gastroesophageal, and biliary tract cancers were 34%, 50%, and 11%, respectively. Eighteen patients (36%) received therapy for at least 24 weeks. CONCLUSIONS: FOLFIRABRAX with genotype-guided dosing of irinotecan is tolerable in patients with advanced gastrointestinal cancer and UGT1A1*1*1 or UGT1A1*1*28 genotypes. Too few *28/*28 patients were enrolled to provide conclusive results. Responses occurred across multiple tumor types.

Personalized Management of Chemotherapy-Induced Peripheral Neuropathy Based on a Patient Reported Outcome: CALGB 40502 (Alliance).

Chemotherapy-induced peripheral neuropathy (henceforth, neuropathy) is often dose limiting and is generally managed by empirical dose modifications. We aimed to (1) identify an early time point that is predictive of future neuropathy using a patient-reported outcome and (2) propose a dose-adjustment algorithm based on simulated data to manage neuropathy. In previous work, a dose-neuropathy model was developed using dosing and patient-reported outcome data from Cancer and Leukemia Group B 40502 (Alliance), a randomized phase III trial of paclitaxel, nanoparticle albumin-bound paclitaxel or ixabepilone as first-line chemotherapy for locally recurrent or metastatic breast cancer. In the current work, an early time point that is predictive of the future severity of neuropathy was identified based on predictive accuracy of the model. Using the early data and model parameters, simulations were conducted to propose a dose-adjustment algorithm for the prospective management of neuropathy in individual patients. The end of the first 3 cycles (12 weeks) was identified as the early time point based on a predictive accuracy of 75% for the neuropathy score after 6 cycles. For paclitaxel, nanoparticle albumin-bound paclitaxel, and ixabepilone, simulations with the proposed dose-adjustment algorithm resulted in 61%, 48%, and 35% fewer patients, respectively, with neuropathy score ≥8 after 6 cycles compared to no dose adjustment. We conclude that early patient-reported outcome data on neuropathy can be used to guide dose adjustments in individual patients that reduce the severity of future neuropathy. Prospective validation of this approach should be undertaken in future studies.

Development and Preliminary Clinical Activity of PD-1-Guided CTLA-4 Blocking Bispecific DART Molecule.

Combination immunotherapy with antibodies directed against PD-1 and CTLA-4 shows improved clinical benefit across cancer indications compared to single agents, albeit with increased toxicity. Leveraging the observation that PD-1 and CTLA-4 are co-expressed by tumor-infiltrating lymphocytes, an investigational PD-1 x CTLA-4 bispecific DART molecule, MGD019, is engineered to maximize checkpoint blockade in the tumor microenvironment via enhanced CTLA-4 blockade in a PD-1-binding-dependent manner. In vitro, MGD019 mediates the combinatorial blockade of PD-1 and CTLA-4, confirming dual inhibition via a single molecule. MGD019 is well tolerated in non-human primates, with evidence of both PD-1 and CTLA-4 blockade, including increases in Ki67+CD8 and ICOS+CD4 T cells, respectively. In the ongoing MGD019 first-in-human study enrolling patients with advanced solid tumors (NCT03761017), an analysis undertaken following the dose escalation phase revealed acceptable safety, pharmacodynamic evidence of combinatorial blockade, and objective responses in multiple tumor types typically unresponsive to checkpoint inhibitor therapy.

Prolonged Pharmacokinetic Interaction Between Capecitabine and a CYP2C9 Substrate, Celecoxib.

This study investigated the time course and magnitude of the pharmacokinetic interaction between capecitabine and the cytochrome P450 (CYP) 2C9 substrate celecoxib, with implications for coadministration of fluoropyrimidines with CYP2C9 substrates such as warfarin. Patients received celecoxib 200 mg orally twice daily continuously, with capecitabine (1000 mg/m2 orally twice daily for 14 days every 21 days) starting 7 days later. Assessment of the drug-drug interaction (DDI) potential was performed using equivalence testing, which assumes that there is no clinically relevant DDI when the calculated 90% confidence intervals (CIs) of the drug exposure ratios fall within the range of 0.80 to 1.25. Comparison of steady-state pharmacokinetic parameters of celecoxib between day 7 (cycle 0, celecoxib only) and day 14 (cycle 1, celecoxib + capecitabine) showed geometric mean ratios of 1.24 (90%CI, 1.04-1.49), 1.30 (1.11-1.53) and 1.28 (1.11-1.47) for maximum plasma concentration, minimum plasma concentration, and area under the concentration-time curve from time zero to 8 hours, respectively. Comparison of day 7 vs day 21 (cycle 1, after 1 week washout of capecitabine) showed a further increase in the geometric mean ratio of maximum plasma concentration (1.39; 90%CI, 1.16-1.66), minimum plasma concentration (1.53; 1.10-2.12) and area under the concentration-time curve from time zero to 8 hours (1.41; 1.19-1.68). Because the 90%CIs fell outside the prespecified equivalence margin, we conclude that coadministration results in a DDI (increased celecoxib exposure) that persists for at least 7 days after capecitabine discontinuation. Close monitoring should be undertaken when administering fluoropyrimidines with CYP2C9 substrates with narrow therapeutic indexes while also weighing the benefits and risks for individual patients.

Capecitabine and Celecoxib as a Promising Therapy for Thymic Neoplasms.

OBJECTIVES: For patients with unresectable or metastatic thymic epithelial neoplasms, few therapy options are available and outcomes are poor. This case series demonstrates that the combination of capecitabine and celecoxib may be a promising therapeutic option for these patients. MATERIALS AND METHODS: The current report describes the outcomes of 5 patients with thymic neoplasms treated on a drug-drug interaction study of capecitabine and celecoxib in patients with advanced solid malignancies (NCT01705106) conducted at the University of Chicago, plus a sixth patient treated with the same regimen outside of the protocol. RESULTS: Six patients with thymic neoplasms were treated with capecitabine 1000 mg/m twice daily and celecoxib 200 mg twice daily, day 1 to day 14 on a 21-day cycle. This included 3 patients with thymic carcinoma, 1 with thymic neuroendocrine tumor, and 2 with thymomas. Objective response rates were noted in 3 of 6 patients. Two of the 3 thymic carcinoma patients had complete responses, and the third had a partial response. Best response for the other patients included stable disease for both thymoma patients and progressive disease for the thymic neuroendocrine patient. Other than grade 3 palmar-plantar erythrodysesthesia, which developed in 4 of 6 patients and required dose reductions, the regimen was well tolerated. CONCLUSIONS: This case series suggests that capecitabine plus celecoxib may be an effective and well-tolerated treatment option for patients with thymic carcinoma. Further studies should be carried out to establish the efficacy of capecitabine plus celecoxib in thymic carcinoma, and to determine whether monotherapy with capecitabine would be similarly effective.