Efficacy and Safety of Nivolumab and AVD in Early-Stage Unfavorable Hodgkin Lymphoma: Extended Follow-up from the GHSG Phase II Nivahl Trial

Background

The primary analysis of the investigator-sponsored randomized multicenter phase II GHSG NIVAHL trial showed feasibility and excellent short-term efficacy of anti-PD1 based 1^st-line treatment of early-stage unfavorable classical Hodgkin lymphoma (cHL). Achieving long-term disease control without excessive treatment-related morbidity is of utmost importance when developing innovative 1^st-line cHL therapies. Duration of response and development of persisting immune-related toxicities are of concern in the setting of 1^st-line anti-PD1 treatment.

Methods

NIVAHL enrolled treatment naïve early-stage unfavorable cHL patients at 28 German centers and individuals were randomized to either receive fully concomitant 4x Nivo-AVD (group A) or sequential 4xnivolumab, followed by 2x Nivo-AVD and 2x AVD (group B). Both groups received consolidative 30Gy IS-RT and the primary endpoint was complete response (CR) rate at end of study treatment. Detailed methods, patient characteristics and the primary endpoint analysis of NIVAHL have been recently published (Bröckelmann PJ et al. JAMA Oncol 2020). Herein we present extended follow-up of the NIVAHL trial to assess efficacy in terms of 2-year progression-free (PFS) and overall survival (OS) as well as safety with regards to long-term toxicities or organ impairment documented during the first year of follow-up after treatment.

Results

A total of 109 patients with cHL confirmed by central pathology review were enrolled between 04/2017 – 10/2018 and followed for a median of 20 and 21 months in groups A (n=55) and B (n=54), respectively, for the present analysis.

All of the 7 patients deemed in partial remission (PR) at end of study treatment (EOT) converted into an ongoing CR after end of study without additional treatment during follow-up. With no relapse and no death observed since the primary analysis, the 2-year PFS estimates are 100% and 98% (95%CI 88-100%) in groups A and B, respectively, and the 2-year OS is 100% in both groups.

With a median observation time for late-toxicities of 14 months after EOT (range 6-26 months) among 103 patients, any potentially treatment-related AE during follow-up was reported in 65% of patients (A: 74%, B: 56%). The highest documented CTCAE grade of late AEs was °I in 33%, °II in 25% and °III in 7% of patients with no °IV-V AEs observed. A total of 54% had at least one late event related to AVD, 47% to nivolumab and 32% to RT, with multiple relations attributable per event. Mean FEV1 and DLCOc did not decrease from baseline (91.1% -> 96.4% and 86.2% -> 83.3%, respectively). Decreased LVEF after EOT was reported in 2/56 patients with available data (4%). After EOT, 18% of patients required medication for adverse events. Corticosteroid ≥ and < 10mg prednisolone equivalent was required in 3% and 2% of patients, respectively, for a toxicity at any time during follow-up. No patient required corticosteroid treatment at last available follow-up.

Most frequent toxicities reported after EOT included fatigue (21%), hypothyroidism (17%), respiratory tract disorders (16%), leukopenia (14%) and nervous system disorders (14%). Hypothyroidism was the event most frequently solely attributed to nivolumab during follow-up. The median time to onset after EOT was 5 months and affected patients nearly exclusively female (15/16 [94%]). After median follow-up of 10 months (range 0-21), hypothyroidism remained unchanged in 10 of 16 affected patients and resolved in 3 patients.

Conclusion

The excellent disease control of concomitant and sequential nivolumab and AVD in early-stage unfavorable cHL is confirmed with the currently available follow-up. Treatment-related toxicities ongoing or emerging during follow-up are predominantly associated with chemo- and/or RT. The most frequent nivolumab-associated late toxicity is hypothyroidism. No patient currently requires chronic corticosteroid treatment.