Everolimus Plus RCHOP-21 Is Safe and Highly Effective for New Untreated Diffuse Large B-Cell Lymphoma (DLBCL): Results of the Phase I Trial NCCTG1085 (Alliance)

Background: The PI3K/mTORC pathway is upregulated in DLBCL and can be targeted with mTORC1 inhibitors such as everolimus. Everolimus has demonstrated single agent activity in relapsed DLBCL (Leukemia. 2011; 25(2):341-7). These data provide the rationale to combine everolimus with standard RCHOP-21 to improve the effectiveness of upfront therapy for DLBCL.

Methods: A phase I study was designed to determine the maximum tolerated dose of everolimus on days 1-10 or 1-14 in combination with RCHOP-21 along with a feasibility cohort to examine response in patients with newly diagnosed CD20+ DLBCL. Response assessment was evaluated using PET/CT and standard criteria.

Results: We previously reported (J Clin Oncol 33, 2015 suppl; 8518) that in the phase I portion of trial N1085 that the dose of everolimus recommended for further study was everolimus 10 mg daily days 1-14; RCHOP day 1 and pegfilgrastim 6 mg day two for each of six 21-day cycles. The trial has now completed enrollment with a total of 26 patients. Two phase I patients were replaced during cycle 1 for personal, non-medical issues leaving 24 eligible patients for response assessment. The median age was 59.5 years (23 - 78); 42% were female; 18 (75%) stages III/IV; 12 (50%) had an elevated LDH; 29% had a high IPI score; and 4 (17%) had B-symptoms. Genotype was performed by immunohistochemistry using the Hans algorithm and 54% (13/24) were non-GCB; 13 (5 GCB, 8 non-GCB) had FISH for double hit and all were negative.

Twenty-one (88%) patients received everolimus at 10 mg d1-14; the other three patients received 10 mg d1-10. Twenty-two (92%) patients received all 6 cycles. All patients have now completed therapy and the overall response rate was 96% (23/24) with 23 patients attaining functional CR by PET/CT. The remaining patient went off study for refusal in cycle 1, received further RCHOP-21 off study, and attained a CR off study. The median follow-up for the 24 patients is now 16.8 months (7.3 - 35.7) with 20 patients having ≥12 months of follow-up and 8 patients having ≥24 months of follow-up. To date, none of the 24 patients have died and none have experienced relapse with DLBCL. One patient relapsed 16 months from DLBCL diagnosis with a biopsy-proven follicular grade 1 NHL and received off-study Zevalin and achieved a second CR. The most common grade 3/4 toxicity was hematologic with 71% of patients having grade 4. Five (21%) patients had febrile neutropenia. Only 1 patient had grade 3 hyperglycemia and 3 patients had grade 3 hypertriglyceridemia. Reversible rash and pneumonitis were observed in 1 case each.

Conclusions: The mTORC1 inhibitoreverolimus at 10 mg daily d1-14 of a standard RCHOP-21 cycle is tolerable with a 96% CR rate in both GCB and non-GCB DLBCL. With a median follow-up of 16.8 months and 8 patients out ≥24 months, the lack of DLBCL relapse is encouraging. Longer follow-up and a larger trial will be necessary to confirm the benefits of this novel combination. Clinical trial information: NCT01334502