Binimetinib in combination with nivolumab or nivolumab and ipilimumab in patients with previously treated microsatellite-stable metastatic colorectal cancer with RAS mutations in an open-label phase 1b/2 study

BACKGROUND

In patients with previously treated RAS-mutated microsatellite-stable (MSS) metastatic colorectal cancer (mCRC), a multicenter open-label phase 1b/2 trial was conducted to define the safety and efficacy of the MEK1/MEK2 inhibitor binimetinib in combination with the immune checkpoint inhibitor (ICI) nivolumab (anti-PD-1) or nivolumab and another ICI, ipilimumab (anti-CTLA4).

METHODS

In phase 1b, participants were randomly assigned to Arm 1A (binimetinib 45 mg twice daily [BID] plus nivolumab 480 mg once every 4 weeks [Q4W]) or Arm 1B (binimetinib 45 mg BID plus nivolumab 480 mg Q4W and ipilimumab 1 mg/kg once every 8 weeks [Q8W]) to determine the maximum tolerable dose (MTD) and recommended phase 2 dose (RP2D) of binimetinib. The MTD/RP2D was defined as the highest dosage combination that did not cause medically unacceptable dose-limiting toxicities in more than 35% of treated participants in Cycle 1. During phase 2, participants were randomly assigned to Arm 2A (binimetinib MTD/RP2D plus nivolumab) or Arm 2B (binimetinib MTD/RP2D plus nivolumab and ipilimumab) to assess the safety and clinical activity of these combinations.

RESULTS

In phase 1b, 21 participants were randomized to Arm 1A or Arm 1B; during phase 2, 54 participants were randomized to Arm 2A or Arm 2B. The binimetinib MTD/RP2D was determined to be 45 mg BID. In phase 2, no participants receiving binimetinib plus nivolumab achieved a response. Of the 27 participants receiving binimetinib, nivolumab, and ipilimumab, the overall response rate was 7.4% (90% CI: 1.3, 21.5). Out of 75 participants overall, 74 (98.7%) reported treatment-related adverse events (AEs), of whom 17 (22.7%) reported treatment-related serious AEs.

CONCLUSIONS

The RP2D binimetinib regimen had a safety profile similar to previous binimetinib studies or nivolumab and ipilimumab combination studies. There was a lack of clinical benefit with either drug combination. Therefore, these data do not support further development of binimetinib in combination with nivolumab or nivolumab and ipilimumab in RAS-mutated MSS mCRC.

TRIAL REGISTRATION

NCT03271047 (09/01/2017).

Prognostic factors for non-Hodgkin's lymphoma patients treated with chemotherapy may not predict outcome in patients treated with rituximab

Several factors predict outcome for patients with non-Hodgkin's lymphoma (NHL) after chemotherapy. However, predictors of response to rituximab have not been identified. Baseline characteristics for 166 NHL patients (130 follicular) in a phase III trial of rituximab were analysed by univariate and multivariate methods to determine whether any of 27 factors predict response and/or response duration. In a univariate analysis, response to rituximab was associated with follicular histology, no prior fludarabine therapy, prior autologous bone marrow transplantation (ABMT), lack of bone marrow involvement or extranodal disease, positive bcl-2 in blood, and fewer relapses. By univariate analysis, longer median time to progression (TTP) and/or duration of response (DR) after rituximab therapy was associated with International Prognostic Index lower-risk group, multiagent chemotherapy, and low/normal serum lactate dehydrogenase (LDH) or beta2 microglobulin. In the multivariate analysis, response to rituximab correlated with follicular histology, prior ABMT, multiagent chemotherapy, and no bone marrow involvement; longer TTP and/or DR correlated with low/normal serum LDH or beta2 microglobulin, high CD3+ cells, and response to last chemotherapy. The follicular lymphoma international prognostic index (FLIPI) did not correlate consistently with response to rituximab or response duration. Several factors associated with prognosis following chemotherapy did not correlate with response to rituximab or response duration. NHL patients can respond to rituximab despite having factors associated with a poor outcome to chemotherapy.

Phase I/II Study of Galiximab, an Anti-CD80 Antibody, for Relapsed or Refractory Follicular Lymphoma

Purpose

This multicenter, dose-escalation study evaluates the safety, pharmacokinetics, and efficacy of galiximab (anti-CD80 monoclonal antibody) in patients with relapsed or refractory follicular lymphoma.

Patients and Methods

Patients had follicular lymphoma that had relapsed or failed to respond to primary therapy; the majority (90%) presented with stage III or IV disease. Four weekly intravenous infusions of galiximab were administered at doses of 125, 250, 375, or 500 mg/m2.

Results

Thirty-seven patients received galiximab treatment and were evaluated for safety; 35 were assessable for response. Antibody infusions were safe and well tolerated with no dose-limiting toxicities. A total of 22 (60%) of 37 patients experienced adverse events related to galiximab. All but one of the events were grade 1 or 2; the most common were fatigue, nausea, and headache. Cytopenias were rare; only one patient experienced anemia and febrile neutropenia, which were unrelated to galiximab and resolved after treatment. No patient developed antigaliximab antibody formation. The mean serum half-life ranged from 13 to 24 days. The overall response rate was 11% (two complete responses and two partial responses). Time to best response was delayed (months 3, 6, 9, and 12). Twelve patients (34%) maintained stable disease. Nearly half of all patients (49%) had a decrease in indicator lesions. Two responders remain on study without progression (22 and 24.4 months).

Conclusion

The favorable safety profile of galiximab and evidence of single-agent biologic activity and dose-dependent pharmacokinetics support further evaluation of galiximab as a treatment for follicular lymphoma, possibly in combination with other lymphoma therapies.

Prolonged Clinical and Molecular Remission in Patients With Low-Grade or Follicular Non-Hodgkin's Lymphoma Treated With Rituximab Plus CHOP Chemotherapy: 9-Year Follow-Up

Purpose

Long-term follow-up with updated time to disease progression (TTP) and duration of response (DR) data are presented from a multicenter, phase II trial of rituximab/cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) combination therapy in 40 patients with CD20+, B-cell, non-Hodgkin's lymphoma (NHL). Revised response rates based on International Workshop Response Criteria are also provided.

Patients and Methods

Enrollment began in April 1994 and consisted of patients with histologically confirmed, low-grade, B-cell lymphoma who had received no prior chemotherapy or who had no more than four prior standard therapies. Patients received six cycles of CHOP and six infusions of rituximab.

Results

Eight (21%) of the 38 treated patients were classified as International Working Formulation (IWF) A, 16 (42%) were IWF B, 13 (34%) were IWF C, and one (3%) was IWF D. Nine (24%) of 38 patients had received prior chemotherapy. Nine (24%) of 38 were considered poor risk according to the Follicular Lymphoma International Prognostic Index. Overall response rate was 100%; 87% of patients achieved a complete response or unconfirmed complete response. The median TTP and DR were 82.3 months and 83.5 months, respectively. Seven of eight patients who were bcl-2 positive at baseline converted to negative, and three of the seven patients have sustained the molecular remission.

Conclusion

Although a cure has not been found yet for follicular NHL, the R-CHOP combination provides a lengthy response duration in patients with relapsed or newly diagnosed indolent NHL.

Clearing of cells bearing the bcl-2 [t(14;18)] translocation from blood and marrow of patients treated with rituximab alone or in combination with CHOP chemotherapy

PURPOSE

Patients who were PCR-positive for B-cell leukemia-lymphoma 2 (bcl-2) gene rearrangement [t(14;18)] were evaluated for responses to rituximab alone or combined with CHOP.

PATIENTS AND METHODS

Patients had relapsed or refractory low-grade or follicular non-Hodgkin's lymphoma (IWF: A-D). The single-agent trial used 375 mg/m2 weekly x 4; combination therapy included six cycles of CHOP and six 375 mg/m2 infusions of rituximab. Bcl-2 analyses of bone marrow (BM) and peripheral blood (PB) samples at base-line and following therapy were performed using a PCR assay.

RESULTS

In the single-agent trial, of 70 patients whose peripheral blood (PB) was bcl-2 positive at baseline, 36 became bcl-2-negative, 13 remained positive, and 21 varied between positive and negative. The overall response rates (ORRs) were 72%, 31%, and 57%, respectively. Twelve of twenty-two patients with repeat bone marrow (BM) samples were bcl-2-negative three months post-treatment. Of 18 patients in the combination trial, 8 were bcl-2 positive in PB and/or BM. All of seven patients positive in PB at baseline and six of seven patients positive in BM were negative at the end of therapy; all patients responded to treatment (100% ORR).

CONCLUSIONS

Rituximab, alone or combined with CHOP, eradicated bcl-2 positive cells from PB and BM in over half of the patients treated and was associated with a high overall clinical response rate. The impact on disease-free and overall survival awaits long-term follow up.