So, in the meantime for so many people Rituxan is used a lot, and then the question is when we talked about maintenance therapy, for how long? Here's a question from Janice in Tulsa, Oklahoma. You can help me make sense of this. She says, 'My mom did two-and-a-half years, or five treatments of Rituxan, as a first-line treatment with nothing else, one year off and then more node involvement, so then she had six CHOP-R treatments.' She says, 'Now it's time to decide whether to do every three months or six months of Rituxan, and the oncologist says the dose for the three-month protocol is approximately one-third of the six months, and also if the three-month is chosen you only do this for a year compared to if you do the six months you do it over two years.'
You can help us make sense of that, but I guess it's trying to understand how to choose the dosage. It would seem like it would be difficult for a patient in how do you assess which is more effective?
That's a great question. This case is pretty typical with what we would see with follicular lymphoma. As I mentioned before, patients, if they get treated with an initial course of rituximab with four, five, or eight doses, usually have remissions that last up to a year or two years and then they will usually progress. In this case, it sounds like her mother was treated with rituximab plus CHOP, which we would anticipate would have a better response than just rituximab alone, and now the question is whether to give maintenance after that setting.
We don't have the answer completely, but there was a study in the Dutch HOVON group, which very convincingly demonstrated that giving maintenance therapy after R-CHOP chemotherapy did greatly prolong the time to progression, and the way they did it in that study was one dose every three months for two years. Most of the maintenance schedules have been for two years. They have varied in doses. One study used four doses every six months for two years, and the other studies have used essentially one dose every three months; so, four doses every six months versus one dose every three months, and as you can see, there is less drug used in the one dose every three months, and that's what I personally use in most of my clinical practice right now is the one dose every three months. That's where we have most of the clinical trial evidence, and there is no data to suggest at this point that they are different, but they have not been compared head-to-head, and if someone wanted to do one versus the other, there is no strong argument, but I would do it for two years because that's what most clinical trials are doing.