Abstract P4-07-16: B-IMMUNE final analysis: a phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers

Background: Neoadjuvant association of immune checkpoints inhibitors (ICI) and dose dense chemotherapy is promising for triple negative breast cancers (TNBC). However, response rates vary from one study to another. Timing, best chemotherapy partner and efficacy in less immunogenic breast cancer (BC), like luminal B tumors, should be further investigated. This study evaluates for TNBC and luminal B HER2(-) BC the neoadjuvant treatment with paclitaxel followed by a short combination of an anti-PD-L1 antibody with anthracyclines. Method B-IMMUNE (NCT03356860), a multicentric phase Ib/II prospective trial, included patients with stage I to III luminal B HER2(-) or TNBC treated with paclitaxel 80mg/m2 weekly from week 1 to 12 followed by 4 cycles of epirubicine 90mg/m2 and cyclophosphamide 600 mg/m2 (EC) Q2W in a neoadjuvant setting. Phase Ib evaluated a single infusion of durvalumab (anti-PD-L1) combined with the 3rd cycle of EC. Phase II evaluated infusions of durvalumab with the 1st and 3rd EC cycles. Surgery was planned 3 weeks after the last EC cycle. Primary objectives were safety and pathological complete response (pCR) rate compared to a historical control. Secondary endpoint was the overall response rate (ORR) based on breast MRI. Eleven patients were enrolled in a control arm without durvalumab, exclusively for translational research purposes. Based on a 2-stage Simon design with an α = 0.1 and β = 0.1, 22 TNBC patients were needed in the phase II to test a null hypothesis of 30% pCR rate against a one-side alternative of 60%, and 24 luminal B BC patients to test a null hypothesis of 15% pCR rate against a one-side alternative of 40% (including an additional accrual margin of 10% for eventual dropouts). At least 9 pCRs had to be observed among the first 20 evaluable TNBC patients and 6 among the first 22 evaluable luminal B patients to rule out the null hypothesis. Results This analysis concerns the 50 patients treated with the experimental treatment, 3 from the phase Ib and 47 from the phase II part. Median age was 51 y-old (31 to 72y), tumor subtypes were 24 TNBC, 25 Luminal B and one sarcoma excluded from the efficacy analysis. Seven (14%) patients had a stage I tumor, 17 (34%) a stage IIA, 13 (26%) a stage IIB, 8 (16%) a stage IIIA, 4 (8%) a stage IIIB and 1 (2%) a stage IIIC. Concerning safety, 232 AEs were reported on 39/50 patients and 34 (14,6%) were graded ≥ 3. The 5 most frequent all-grade AEs were fatigue (8,2%), diarrhea (5,6%), neutropenia (5,2%), anemia and nausea (4,3%). Most frequent grade 3 AEs were anemia and neutropenia (14,7%). Among 4 immune-related adverse events, all were thyroid disorders. One patient died 10 months after the end of treatment due to progressive disease in the liver. Forty-six of the 47 phase II patients were evaluable for efficacy. pCR was reported in 12/22 TNBC patients (55%) and 8/24 luminal B HER2(-) patients (33%). Subgroup analyses based on PD-L1 expression and TILs score are planned. Conclusions The B-IMMUNE study met its primary objective showing a significant improvement in pCR versus the historical control in both TNBC and in Luminal B HER2(-) BC cohorts with the addition of only 2 doses of durvalumab to the anthracyclines. The safety profile is comparable to those previously described with reported immune related adverse events limited to thyroid endocrine disorders.

Citation Format: Alix Devaux, Gabriela Beniuga, Claire Quaghebeur, Stéphanie Henry, Mieke Van Bockstal, Christine Galant, Paul Delrée, Jean-Luc Canon, Brigitte Honhon, Dominique Korman, Vincent Verschaeve, Christophe Lonchay, Sarah Lefevre, Lionel D’Hondt, Martine Berlière, Sophie Delmarcelle, Jean-Michel Mine, Timour Willems, Gebhard Müller, Nathalie Myant, Isabelle Bar, Sandy Haussy, Pierre G. Coulie, François P. Duhoux, Javier Carrasco. B-IMMUNE final analysis: a phase Ib/II study of durvalumab combined with dose-dense EC in a neoadjuvant setting for patients with locally advanced luminal B HER2(-) or triple negative breast cancers. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-16.

Randomized Phase 2 Study Comparing Pathological Responses of Resected Colorectal Cancer Metastases after Bevacizumab with mFOLFOX6 or FOLFIRI (BEV-ONCO Trial)

Retrospective studies reported that preoperative oxaliplatin-based chemotherapy increased pathological response (PR) in patients resected for colorectal liver metastases (CRLM). This multicenter prospective randomized (1/1) phase II trial evaluated PR on resected CRLM after preoperative mFOLFOX6 (arm A) or FOLFIRI (arm B) + bevacizumab. The primary endpoint was the major pathological response rate (MPRR), defined as the percentage of patients presenting CRLMs with mean tumor regression grade (TRG) < 3. Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). Out of 65 patients, 57 patients (28 and 29 in arm A/B) were resected for CRLM (one patient with lung metastases). Clinical and treatment characteristics were similar in both arms. One-month postoperative complications were 39.3%/31.0% in arm A/B (p = 0.585). MPRR and complete PR were 32.1%/20.7% (p = 0.379) and 14.3%/0.0% (p = 0.052) in arm A/B, respectively. PFS and OS were not different. Patients with PR among all CRLMs (max TRG ≤ 3; 43.8% of patients) had a lower risk of relapse (PFS: HR = 0.41, 95%CI = 0.204−0.840, p = 0.015) and a tendency towards better survival (OS: HR = 0.34, 95%CI = 0.104−1.114, p = 0.075). The homogeneity of PR was associated with improved PFS/OS. This trial fails to demonstrate a significant increase in MPRR in patients treated with mFOLFOX6-bevacizumab but confirms PR as an important prognostic factor.

Phase III trial of docetaxel (D), estramustine (E), and prednisone versus docetaxel plus prednisone in patients with metastatic hormone-refractory prostate cancer (HRPC)

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Background: D alone or in combination with E improves survival of pts with metastatic HRPC. Whether E is necessary in combination with D is controversial. Preclinical data suggest a synergistic activity between D and E. Phase II as well as small randomized trials support this hypothesis, although indirect comparisons between the large phase III studies are not in favor of D/E combination. We conducted a randomized, prospective, multicentric study to compare D versus D/E. Methods: 150 metastatic HRPC were randomized (minimisation, stratification parameters: PSA level, ECOG, previous E use (38 pts), and center) between D (35 mg/m2 on day 2 and 9, every 3 wks) and D in combination with E (280 mg PO tid on days 1 to 5 and 8 to 12, coumadin 1mg/d). E was the only difference between the two treatment arms. All the pts received prednisone (10 mg/d). The primary endpoint was PSA response rate (decrease in PSA > 50% from baseline) and the study was powered to detect a 25% difference in PSA response rate. Results: No significant difference was found for PSA response (D/E: 50/68 (73%); D: 48/69 (69%)), time to PSA progression (median 205 days for D/E and 210 days for D), duration of PSA response (median 185 days for D/E and 220 days for D), progression-free survival (median 186 days for D/E and 195 days for D), response rate according to RECIST, and overall survival (median 617 days for D/E and 629 days for D). PSA < 4 ngr/mL occurred in 28/68 pts (41%) in D/E and in 17/69 (25%) in D (p=0.04). More pts had at least one grade 3/4 NCI-CTC toxicity in D/E (33/75 pts; 45%) compared to D (16/75 pts; 21%) (p=0.003). The main difference was grade 3/4 digestive toxicity (D/E:15% and D:4%; p=0.017). Serious adverse events were reported more frequently in D/E than D: 20 vs 9 (p=0.03). In D/E, the most frequent grade 3/4 toxicities were digestive (15%) and venous thrombosis (12%). In D, the most frequent grade 3/4 toxicity was anemia (9%) and venous thrombosis (8%). Conclusions: Our study did not show any clinically relevant advantage in term of efficacy for the addition of E to D. Both regimens were well-tolerated although the toxicity profile was in favor of D without E. Our study does not support the addition of E to D to treat pts with HPRC.

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