Clinical Trial of Oral Rigosertib (Estybon)

[Samantha R.]

Hi. My name is Samantha and I am new to this list serve. My mom, age 66, was diagnosed with MDS - RARS-T - about three months ago. She has had two transfusions (and no luck with growth hormone injections) and now her doctor wants to put her in a clinical study of oral Rigosertib (Estybon). Has anyone been part of this study and on this drug? I'd love to hear about your experiences, results, side-effects. Many thanks!!

[Neil Cuadra]

Hi Samantha.

Rigosertib is called not only by its trade name Estybon but also by the name ON 01910, so be sure to search under multiple names when looking for information about it.

In the forums we first talked about rigosertib here when it was a new drug undergoing initial testing, and here last year. A few forum users have mentioned the rigosertib clinical trials, including user "sae36" in a post here.

There are several rigosertib trials currently open, including a Phase II dosage study and a Phase III comparison with other treatments for higher-risk patients. Do you know which trial her doctor is talking about? Has he or she explained the pros and cons of being in a clinical trial and whether there's an alternative treatment if you choose not to participate in the trial?

[Birgitta-A]

Hi Samantha,
You don't write anything about your mother's counts or chromosome aberrations (if she has any). Many patients with low risk MDS only get supportive therapy like growth factors and transfusions.

Have you asked her dr why he will try more active treatment?
Kind regards
Birgitta-A
73 yo, dx MDS Interm-1 2006, transfusion dependent from dx, supportive therapy until 2010 when I started to take Thalidomide + Prednisone with positve effect.

[sae36]

My father received this therapy in Phase 1 trial, his response was fantastic. The physician has continued him on the rigosertib - 560 mg and he had been transfusion free for 14 weeks.

[Samantha R.]

Thanks to all who responded and for the good information. We are seeing my mother's doctor on Wed so I will be armed with some good questions to ask. As for Brigitta's question about my mom's counts - I don't have the exact number but her MDS effects only her red blood count and platlettes. The doctor said that she should try this drug so that she can lessen her dependence on blood transfusions, which the doctor said, she could develop antibodies to and down the road suffer the side effects of iron overload. Samantha

[Birgitta-A]

Hi Samantha,
Your doctor is of cause right about that we can develop antibodies when we get transfusions - I have many so called irregular antibodies myself - and get iron overload. Still many patients continue with supportive therapy until there is some more serious reason for more active treatment.

You could write dow your mother's counts so you can follow them. In RARS-T the patients have high platelets - as far as I understand patients with RARS-T are treated as RARS patients and have good prognosis.

Hope your mother will have positve effect when she is treated with Rigosertib!
Kind regards
Birgitta-A