Since 2011 most clinicians treating primary myelofibrosis have used the dynamic International Prognostic Scoring System (DIPPS)-plus model to determine the most appropriate therapy for their patients. Recently, a number of prognostic models that improve on DIPPS-plus have been developed, which have complicated the decision-making process for clinicians. In an article in Nature, specialists at the Mayo Clinic recently reviewed the options and provided recommendations designed to clarify which algorithm to use when.

Blood test tube. Source: Getty

The two new models are the mutation-enhanced international prognostic scoring system for transplant-age patients (MIPPS70) and its variants and the genetically inspired prognostic scoring system (GIPPS). GIPPS exclusively relies on mutations and karyotype and puts patients in one of four risk categories.

The MIPPS70 algorithm combines mutations and clinical risk factors and is most useful when cytogenetic data is not available.  MIPPS70+ 2.0 uses the data in MIPPS70 plus a three-tiered cytogenetic risk stratification and adjusted hemoglobin thresholds. MIPPS70 2.0 classifies patients into one of five risk groups; MIPPS70 has a three-tier risk structure. Both use an online score calculator (www.mipss70score.it).

The Mayo Clinic team recommend using a stepwise treatment algorithm that begins with the simpler GIPPS model and uses the MIPPS70+ options, when necessary. As they point out, “GIPSS high-risk disease always corresponds to MIPSS70+ very high- or high-risk disease, [so] additional prognostic information might not be necessary before recommending [allogenic stem cell transplant] for patients with GIPSS high-risk disease.” Likewise, GIPPS low-risk disease always corresponds with MIPSS70+ low-risk disease and the recommended management will be continued observation. In neither case is the more complex assessment required by MIPPS required.

For patients in the intermediate categories in the GIPPS model, however, clinicians will want the additional information provided by MIPPS70+ version 2.0. or MIPPS70, if cytogenetic information is absent, but molecular information available. Broadly, patients with intermediate disease will be best managed by observation if they have no treatment-requiring symptoms, while those with symptoms might be best served by clinical trial participation or stem cell transplant.

For patients ineligible for clinical trials or transplant, the Mayo Clinic team recommends palliative options to address symptoms, including conventional drug therapy, ruxolitinib, radiotherapy or splenectomy.