Efficacy of second and third lines of treatment in advanced soft tissue sarcomas: a real-world study

BACKGROUND

Soft tissue sarcomas (STSs) are an uncommon and heterogeneous group of tumours. Several drugs and combinations have been used in clinical practice as second-line (2L) and third-line (3L) treatment. The growth modulation index (GMI) has previously been used as an exploratory efficacy endpoint of drug activity and represents an intra-patient comparison.

METHODS

We performed a real-world retrospective study including all patients with advanced STS who had received at least 2 different lines of treatment for advanced disease between 2010 and 2020 at a single institution. The objective was to study the efficacy of both 2L and 3L treatments, analysing the time to progression (TTP) and the GMI (defined as the ratio of TTP between 2 consecutive lines of therapy).

RESULTS

Eighty-one patients were included. The median TTP after 2L and 3L treatment was 3.16 and 3.06 months, and the median GMI was 0.81 and 0.74, respectively. The regimens most frequently used in both treatments were trabectedin, gemcitabine-dacarbazine, gemcitabine-docetaxel, pazopanib and ifosfamide. The median TTP by each of these regimens was 2.80, 2.23, 2.83, 4.10, and 5.00 months, and the median GMI was 0.78, 0.73, 0.67, 1.08, and 0.94, respectively. In terms of histotype, we highlight the activity (GMI > 1.33) of gemcitabine-dacarbazine in undifferentiated pleomorphic sarcoma (UPS) and in leiomyosarcoma, pazopanib in UPS, and ifosfamide in synovial sarcoma.

CONCLUSIONS

In our cohort, regimens commonly used after first-line STS treatment showed only slight differences in efficacy, although we found significant activity of specific regimens by histotype.

Bevacizumab in recurrent ovarian cancer: could it be particularly effective in patients with clear cell carcinoma?

PURPOSE

Treatment of recurrent ovarian carcinoma is a challenge, particularly for the clear cell (CCC) subtype. However, there is a preclinical rationale that these patients could achieve a benefit from antiangiogenic therapy. To assess this hypothesis, we used the growth modulation index (GMI), which represents an intrapatient comparison of two successive progression-free survival (PFS).

METHODS

We conducted a retrospective real-world study performed on 34 patients with recurrent ovarian cancer, treated with bevacizumab-containing regimens from January 2009 to December 2017. The primary endpoint was GMI. An established cut-off > 1.33 was defined as a sign of drug activity.

RESULTS

73.5% of patients had high-grade serous ovarian carcinoma (HGSOC), and 17.7% had CCC; 70.6% of patients received carboplatin/gemcitabine/bevacizumab, and 29.4% received weekly paclitaxel/bevacizumab. According to histological subtype, the overall response rate and median PFS were 52% and 14 months for HGSOC and 83.3% and 20 months for CCC, respectively. The overall population median GMI was 0.99; it was 0.95 and 2.36 for HGSOC and CCC, respectively. CCC subtype was significantly correlated with GMI > 1.33 (odds ratio 41.67; 95% confidence interval 3.6-486.94; p = .03).

CONCLUSION

Adding bevacizumab to chemotherapy in recurrent CCC is associated with a remarkable benefit in this cohort. The efficacy of antiangiogenic drugs in CCC warrants further prospective evaluation.

Efficacy and safety of regorafenib compared to placebo and to post-cross-over regorafenib in advanced non-adipocytic soft tissue sarcoma

INTRODUCTION

The placebo-controlled phase-2 REGOSARC trial demonstrated the efficacy of regorafenib in patients with leiomyosarcoma, synovial sarcoma and other non-adipocytic sarcoma but not in liposarcoma. Patients initially allocated to placebo were allowed to receive regorafenib after progression. We report here an updated analysis of the trial including evaluation of regorafenib activity after cross-over.

METHODS

From June 2013 to December 2014, 139 patients were enrolled in the non-adipocytic sarcoma cohorts. Median follow-up is now 32.4 months. Benefit of regorafenib versus placebo in terms of progression-free survival (PFS) and overall survival (OS) from randomisation was estimated by hazard ratio (HR) in Cox models. In the placebo arm, intra-patient benefit of regorafenib after cross-over was evaluated by the growth modulation index (GMI) (GMI was here, for each patient, PFS after cross-over regorafenib divided by PFS with placebo). Furthermore, the activity of delayed (after cross-over) versus early (at study entry) regorafenib was evaluated by comparing PFS after cross-over to regorafenib to PFS after randomisation in the regorafenib arm.

RESULTS

PFS benefit of regorafenib as compared to placebo was confirmed with longer follow-up (HR = 0.50; 95% CI: 0.35-0.71; p < .0001). OS was not statistically significant different (HR = 0.78; 0.54-1.12; p = .18). This finding may partially be explained by the fact that 55/68 patients who progressed on placebo (81%) received cross-over Regorafenib after progression: 59% of them had a GMI ≥ 1.3 (95% CI, 45-71%). Delayed start of regorafenib was associated with a statistically non-significant shorter PFS as compared to early treatment (HR = 1.21; 0.84-1.73; p = .30) without impact on OS.

CONCLUSIONS

Observed PFS confirms that regorafenib warrants further clinical investigation in refractory non-adipocytic sarcomas.