FDA Approval Summary: Tucatinib with Trastuzumab for Advanced Unresectable or Metastatic, Chemotherapy Refractory, HER2-Positive RAS Wild-Type Colorectal Cancer.

On January 19, 2023, the FDA granted accelerated approval to tucatinib in combination with trastuzumab for the treatment of patients with unresectable or metastatic RAS wild-type, HER2-positive colorectal cancer who have received prior treatment with fluoropyrimidine, oxaliplatin, and irinotecan. Approval was based on the pooled analysis of patients receiving tucatinib in combination with trastuzumab in MOUNTAINEER (NCT03043313), an open-label, multicenter trial. The primary endpoint was overall response rate (ORR) by RECIST 1.1 as per blinded central review committee (BIRC) assessment. The main secondary endpoint was duration of response (DOR) per BIRC assessment. Eighty-four eligible patients received the combination tucatinib and trastuzumab. With a median follow-up of 16 months, the ORR was 38% [95% confidence interval (CI): 28-49] and median DOR was 12.4 months (95% CI: 8.5-20.5); 81% of responders had a response lasting more than 6 months. The most common adverse reactions observed in at least 20% of patients receiving tucatinib in combination with trastuzumab were diarrhea, fatigue, rash, nausea, abdominal pain, infusion-related reactions, and fever. FDA concluded that the magnitude of ORR and durable responses observed in patients treated with tucatinib in combination with trastuzumab in the MOUNTAINEER trial are clinically meaningful, particularly in the context of a disease with estimated survival of 6-7 months with available therapy. This is the first approval for the subset of patients with HER2-positive colorectal cancer. This article summarizes the FDA's thought process and review of the data supporting this accelerated approval.

FDA Approval Summary: Pemigatinib for Previously Treated, Unresectable Locally Advanced or Metastatic Cholangiocarcinoma with FGFR2 Fusion or Other Rearrangement.

On April 17, 2020, the FDA granted accelerated approval to pemigatinib (PEMAZYRE, Incyte Corporation) for the treatment of adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with an FGFR2 fusion or other rearrangement as detected by an FDA-approved test. Approval was based on FIGHT-202 (NCT02924376), a multicenter open-label single-arm trial. Efficacy was based on 107 patients with locally advanced unresectable or metastatic cholangiocarcinoma whose disease had progressed on or after at least one prior therapy and had an FGFR2 gene fusion or rearrangement. Patients received pemigatinib, 13.5 mg orally, once daily for 14 consecutive days, followed by 7 days off therapy. Safety was based on a total of 466 patients, 146 of whom had cholangiocarcinoma and received the recommended dose. Efficacy endpoints were overall response rate (ORR) and duration of response (DOR) determined by an independent review committee using RECIST 1.1. ORR was 36% (95% confidence interval: 27-45). Median DOR was 9.1 months. The most common adverse reactions were hyperphosphatemia, alopecia, diarrhea, nail toxicity, fatigue, dysgeusia, nausea, constipation, stomatitis, dry eye, dry mouth, decreased appetite, vomiting, arthralgia, abdominal pain, hypophosphatemia, back pain, and dry skin. Ocular toxicity and hyperphosphatemia are important risks of pemigatinib. The recommended dosage is 13.5 mg orally once daily for 14 consecutive days followed by 7 days off therapy in 21-day cycles. FDA also approved the FoundationOne CDX (Foundation Medicine, Inc.) as a companion diagnostic for patient selection.

FDA Approval Summary: Nivolumab for the Adjuvant Treatment of Adults with Completely Resected Esophageal/Gastroesophageal Junction Cancer and Residual Pathologic Disease.

The FDA approved nivolumab on May 20, 2021, for the adjuvant treatment of completely resected (negative margins) esophageal or gastroesophageal junction cancer (EC/GEJC) in patients who had residual pathologic disease following chemoradiotherapy. The approval was based on data from the double-blind CheckMate 577 trial, which randomly allocated patients to receive nivolumab or placebo. Disease-free survival (DFS) was the primary endpoint. At the time of the final DFS analysis and the prespecified interim overall survival (OS) analysis, the estimated median DFS was 22.4 months [95% confidence interval (CI), 16.6-34.0] in the nivolumab arm versus 11.0 months (95% CI, 8.3-14.3) in the placebo arm, with an HR of 0.69 (95% CI, 0.56-0.85; two-sided P value = 0.0003). An unblinded review of OS did not indicate a detrimental effect on survival. Adverse reactions occurring in ≥20% of patients receiving nivolumab were fatigue/asthenia, diarrhea, nausea, rash, musculoskeletal pain, and cough. Approval of nivolumab is likely to change the treatment paradigm for the adjuvant treatment of patients with completely resected (negative margins) EC/GEJC who have residual pathologic disease following chemoradiotherapy based on the study results and favorable risk:benefit of nivolumab administration.

The Benefit of Chemotherapy in Esophageal Cancer Patients With Residual Disease After Trimodality Therapy.

INTRODUCTION: The objective of this retrospective study was to determine the potential benefits of chemotherapy in esophageal cancer patients treated with chemoradiation followed by surgery. MATERIALS AND METHODS: At our institution, 145 patients completed trimodality therapy from 1993 to 2009. Neoadjuvant treatment predominantly consisted of 5-fluorouracil and cisplatin with a concurrent median radiation dose of 50.4 Gy. Sixty-two patients received chemotherapy postoperatively. The majority (49/62) received 3 cycles of docetaxel. RESULTS: Within the entire cohort, a 5-year overall survival (OS) benefit was found in those who received postoperative chemotherapy, OS 37.1% versus 18.0% (P=0.024). The response after neoadjuvant chemoradiation was as follows: 33.8% had a pathologic complete response and 62.8% with residual disease. A 5-year OS and cause-specific survival (CSS) advantage were associated with postoperative chemotherapy among those with macroscopic residual disease after neoadjuvant therapy: OS 38.7% versus 13.9% (P=0.016), CSS 42.8% versus 18.8% (P=0.048). This benefit was not seen in those with a pathologic complete response or those with microscopic residual. A stepwise multivariate Cox regression model evaluating the partial response group revealed that postoperative chemotherapy and M stage were independent predictors of overall and CSS. CONCLUSIONS: This analysis revealed that patients with gross residual disease after trimodality therapy for esophageal cancer who received postoperative chemotherapy had an improved overall and CSS. These data suggest that patients with residual disease after trimodality therapy and a reasonable performance status may benefit from postoperative chemotherapy. Prospective trials are needed to confirm these results to define the role of postoperative treatment after trimodality therapy.

Safety, efficacy, pharmacokinetics, and pharmacodynamics of the combination of sorafenib and tanespimycin.

PURPOSE: Heat shock protein (Hsp) 90 inhibition affects the Raf kinase signaling pathway and could enhance antitumor effects of sorafenib, a Raf kinase inhibitor. The combination of sorafenib and tanespimycin [17-allyl-amino-geldanamycin (17-AAG); NSC 330507/KOS-953] was evaluated in a phase I trial with the primary objective of defining a phase II dose. PATIENTS AND METHODS: The dose cohorts consisted of fixed continuous oral dosing of 400 mg sorafenib twice daily, starting at 14 days before tanespimycin, which was administered intravenously at escalating doses (starting at 300 mg/m,(2) with 50 mg/m(2) increments), on days 1, 8, and 15 in a 28-day cycle. Toxicity was assessed weekly, and response was evaluated every two cycles. RESULTS: Twenty-seven toxicity-evaluable patients were enrolled and treated at four dose levels. Predominant primary malignancies were renal cancer (12), melanoma (6), and colorectal cancer (4). Dose-limiting toxicities of grade 4 transaminitis and grade 3 hand-foot syndrome in one patient each were observed at 450 mg/m(2) of tanespimycin. One hundred fourteen cycles were administered with a median of four cycles (range 1-17 cycles). Plasma concentrations of sorafenib and metabolites reached steady state after 7 days. Tanespimycin did not alter sorafenib concentrations. Pharmacodynamics showed a decrease in Hsp90 levels and induction of Hsp70. Clinical efficacy was observed in 9 of 12 renal cancer patients and 4 of 6 melanoma patients CONCLUSIONS: Recommended phase II doses of this combination are 400 mg sorafenib twice daily and 400 mg/m(2) tanespimycin on days 1, 8, and 15, every 28 days. Clinical and pharmacodynamic activity was observed in kidney cancer and melanoma.