No abstract

Rituximab-induced acute thrombocytopenia (RIAT), a rare complication of rituximab administration, has not yet been described in follicular lymphoma (FL). A 65-year-old man received rituximab for the treatment of high tumor burden follicular lymphoma in the leukemic phase. The next day, his platelet count abruptly dropped from 85,000 to 5,000/μL, which spontaneously recovered in a few days without specific treatment. We speculate that the occurrence of infusion-related cytokine release syndrome in rituximab-sensitive high tumor burden FL contributed to the development of RIAT. Frequent monitoring of the platelet count is advisable for select patients considered to be at a high risk for RIAT.

No abstract

Discontinuation of tyrosine kinase inhibitors (TKIs) is now a feasible therapeutic goal for patients with chronic phase chronic myeloid leukemia (CML-CP). Whereas approximately half of patients experience molecular relapse, after resuming with any TKI; the majority re-achieve a deep molecular response (DMR). It is unclear whether such patients who re-achieve a durable DMR can discontinue TKI safely again. Here, we retrospectively assessed first, second, and third attempts to stop TKIs in patients with CML-CP. At the first attempt, 28 out of a total of 53 patients achieved sustained treatment-free remission (TFR; 53.4%; 95% confidence interval [CI], 39.0%-65.9%). Subsequently, 10 of 25 patients attempted a second TKI discontinuation, and in all cases, this was after receiving second-generation TKIs.Four of 10 patients successfully achieved TFR (37.5%; 95% CI, 9.9%-65.9%). All patients who relapsed at the second TKI discontinuation attempt were readministered TKIs, and soon achieved at least a major molecular remission. All six second relapse patients had a loss of MR 4.5 at 3 months after TKI discontinuation. These findings suggest that second and third attempts to successfully stop TKI treatment are feasible in patients with CML-CP.

3501 Background: Triplet regimens, FOLFOXIRI, combined with bevacizumab (bev) or panitumumab have been shown to be superior in terms of early tumor shrinkage (ETS) and depth of response (DpR) compared to doublet combinations in patients with RAS wild-type metastatic colorectal cancer (mCRC), in the TRIBE trial ( N Engl J Med 2014) or the VOLFI trial ( J Clin Oncol 2019), respectively. There have been few studies which directly compared cetuximab (cet) with bev when combined with triplet regimen. Therefore, we investigated the efficacy and safety of bev vs. cet in combination with FOLFOXIRI in previously untreated mCRC patients with RAS wild-type tumors. Methods: This trial was a randomized phase II trial to evaluate modified (m)-FOLFOXIRI (irinotecan 150mg/m2, oxaliplatin 85mg/m2, 5-FU 2400mg/m2) plus cet vs. bev as first-line treatment in terms of DpR during the entire course as the primary endpoint in 360 patients with RAS wild-type mCRC. The aim of the trial was to show that median DpR of cet arm was more than 12.5% higher than bev arm, with a power of 85% at a significance level of 0.05. Secondary endpoints included ETS rate at week 8, overall response rate (ORR), progression-free survival (PFS), overall survival (OS), secondary resection rate, and toxicity. Results: A total of 359 patients were enrolled between July 2015 and June 2019. For the full analysis set (median age 65y, 64% male, PS0/1: 91%/9%, left/right primary: 83%/17%), 173 and 175 patients were randomly assigned to the cet and bev arms, respectively. On the cutoff date of September 2020, the median number of cycles administered was 10 (range, 1-51) for the cet arm and 12 (range, 1-51) for the bev arm. Safety data was already reported at the ASCO GI symposium 2021 (J Clin Oncol 39, 2021 suppl 3; abstr 86). The primary endpoint was met (p =.001); 57.4%（-15.0̃100）for the cet arm versus 46.0% （-0.6̃100）for the bev arm. As for primary tumor sidedness, median DpR were 60.3% versus 46.1% (p =.0007) in the left-side and 50.0% versus 41.2% (p =.46) in the right-side. The ETS rate and ORR as the secondary endpoints were 77.8% and 69.1% in the cet arm versus 74.6% and 71.7% in the bev arm, respectively, with no statistical significance. Although the survival data were immature, PFS and OS of both arms were 12.7 months (95%CI 11.5-14.0) and 37.6 months (95%CI 30.8 to 43.0), respectively. Conclusion: The mFOLFOXIRI plus cet has been shown to be significantly superior to the mFOLFOXIRI plus bev in terms of DpR as the primary endpoint in first-line treatment for RAS wild-type mCRC. Clinical trial information: NCT02515734. Clinical trial information: UMIN000018217.