GCC Sickle Cell Disease Patient Flow Model

The funnel starts from carrier-rate-adjusted epidemiology. Carrier frequency reaches 6-7% in Saudi Arabia's Eastern Province and 10-15% in parts of Bahrain and Oman, implying an estimated 140,000-200,000 SCD patients in Saudi Arabia alone and 200,000-250,000 across the GCC, among the highest per-capita burdens outside sub-Saharan Africa. Mandatory premarital carrier screening, in place nationally in Saudi Arabia since the mid-2000s, is measurably cutting new HbSS births by 15-20% a year, but that incidence effect barely dents a prevalent population this large for at least a generation. Newborn screening is in place across most GCC states and captures the large majority of the prevalent population at birth, but a structured adult haematology transition exists only at KFSH&RC, KAMC, and AUH; most other GCC hospitals manage adult SCD within general internal medicine rather than dedicated haematology oversight.

The funnel narrows sharply at registration. NPHC's SCD programme, the largest single rare-disease group it manages by patient count, actively manages an estimated 8,000-10,000 KSA patients under a dedicated annual budget of SAR 200-350 million. That cohort is not the diagnosed population, most SCD patients are diagnosed via newborn screening long before NPHC involvement, it is the population that clears a specific severity and documentation threshold: three or more vaso-occlusive crises a year, formally enrolled for chronic transfusion exchange or iron chelation at KFSH&RC, KAMC, or a comparable centre. Hydroxyurea itself, the SFDA-registered generic standard of care, reaches only 30-40% of eligible patients despite 60-70% eligibility, hampered by monthly CBC monitoring burden and patients viewing it as chemotherapy. The 8,000-10,000-patient NPHC cohort is the near-term addressable opportunity reachable through the existing national-programme channel; the 140,000-200,000-patient prevalence estimate is the total burden a novel agent would need expanded primary-care distribution, not just NPHC registration, to reach.

Every AXLRx patient flow model is built on a five-layer funnel, population, disease burden (E1), diagnosis and registration capture (E2), treatment eligibility (E3), market access (E4), then Year 1-3-5 projections across three scenarios. The registry-versus-epidemiology gap is modelled explicitly as a funnel stage, the care-registration constraint, rather than reconciled into a single number. Delivered as a live Excel workbook, not a static table.

GCC sickle cell disease sources: Al-Qurashi MM (Eur J Haematol 2010), Al-Salem AH et al. (Saudi Med J 2019), the NPHC SCD programme annual report (2022), the Saudi MOH SCD national programme, and the Saudi SCD programme hydroxyurea adherence audit (2021).