React Component not updating with state change

I currently have a reducer that does a deep copy of state and returns it with the updated value.

function countableItems(state = initialState, action) {
    switch (action.type) {
        case types.ADD_TO_SUM:
            let denomMap = findDenomination(state.denomGroups, action),
                nestedCopy = Immutable.fromJS(state);
            return nestedCopy.setIn(['denomGroups', denomMap.group, denomMap.key, denomMap.index, 'sum'], parseFloat(action.value)).toJS();
        default:
            return state;
    }
}

In my render function of the display Component I see the correct updated values in this.props.denoms The render() function builds up child <DenomInput> components, and when I set my breakpoints I see the correct data being passed in

render() {
    let denomGroups = this.props.denoms.map((denom, i) => {
        return (
            Object.keys(denom).map((key) => {
                let denoms = denom[key].map((item, i) => {
                    return <DenomInput denom={item} onDenomChange={this.onDenomChange} key={i}></DenomInput>
                });
                return (<div className="col"><h2>{key}</h2>{denoms}</div>)
            })
        );
    });

    return (
        <div className="countable-item-wrapper">
            <div className="row">
                {denomGroups}
            </div>
        </div>
    );
}

However when the <DenomInput> components render it renders the same value as what they were initially set

import React, { Component } from 'react';
import PropTypes from 'prop-types';

class DenomInput extends Component {
    constructor(props) {
        super(props);
        this.state = { denom: props.denom }
        this.handleKeyUp = this.handleKeyUp.bind(this);
    }

    handleKeyUp = (e) => {
        this.props.onDenomChange(e.target.value, this.state.denom.name);
    }

    render() {
        return (
            <div className="input-group denom">
                <span className="input-group-addon">{this.state.denom.label}</span>
                <input
                    type="text"
                    className="form-control"
                    onChange={this.handleKeyUp}
                    value={this.state.denom.sum} />

                <span className="input-group-addon">{this.state.denom.count | 0}</span>
            </div>
        );
    }
}

DenomInput.PropTypes = {
    denom: PropTypes.object.isRequired,
    onDenomChange: PropTypes.function
}

export default DenomInput;

What piece am I missing to update the view with React and Redux?