KDOQI serum phosphorus targets were defined for: Adolescents aged greater than or equal to (>=) 12 to less than (<) 18 years to be less than or equal to (<=) 5.5 milligrams per deciliter (mg/dL) (1.78 millimoles per liter [mmol/L]); Children aged >=10 years to <12 years to be <= 6.0 mg/dL (1.94 mmol/L). Percentage of participants achieving age-specific KDOQI targets for serum phosphate level was reported only for the participants who had received lanthanum carbonate during part 2 or part 3. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

Per-protocol set 2 (PP2) included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

KDOQI serum phosphorus targets was defined for: Adolescents aged >= 12 < 18 years to be <= 5.5 mg/dL (1.78 [mmol/L]); Children aged >=10 years to <12 years to be <= 6.0 mg/dL (1.94 mmol/L). Percentage of participants achieving age-specific KDOQI targets for serum phosphate level were reported only for the participants who had received calcium carbonate followed by 8 weeks of treatment with lanthanum carbonate in Part 2. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

Per Protocol Set 1 (PP1) included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in serum phosphorus levels in hyperphosphatemic children and adolescents with chronic kidney disease (CKD) who are on dialysis, following treatment with lanthanum carbonate for 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in calcium levels in hyperphosphatemic children and adolescents with CKD who are on dialysis, following treatment with lanthanum carbonate for 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in calcium-phosphorus product levels in hyperphosphatemic children and adolescents with CKD who are on dialysis, following treatment with lanthanum carbonate for 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. The unit of measure for this outcome measure was millimole square per square liter (mmol^2/L^2). Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in serum phosphorus levels in hyperphosphatemic children and adolescents with CKD who are on dialysis, following treatment with calcium carbonate after 8 weeks and lanthanum carbonate after 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in calcium levels in hyperphosphatemic children and adolescents with CKD who are on dialysis, following treatment with calcium carbonate after 8 weeks and lanthanum carbonate after 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Changes from baseline in calcium-phosphorus product levels in hyperphosphatemic children and adolescents with CKD who are on dialysis, following treatment with calcium carbonate after 8 weeks and lanthanum carbonate after 8 weeks were combined and reported. Baseline was defined as the last assessment prior to the first dose of investigational product. The unit of measure for this outcome was millimole square per square liter. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in serum phosphorus levels at the last visit of each 8-week treatment period during Part 2 and monthly during the 6-month extension phase (Part 3) were reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in calcium levels at the last visit of each 8-week treatment period during Part 2 and monthly during the 6- month extension phase (Part 3) were reported.Baseline was defined as the last assessment prior to the first dose of investigational product. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in calcium-phosphorus product levels at the last visit of each 8-week treatment period during Part 2 and monthly during the 6-month extension phase (Part 3) were reported. Baseline was defined as the last assessment prior to the first dose of investigational product. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. The unit of measure of this outcome was millimole square per square liter. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP2 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of treatment with lanthanum carbonate and who had serum phosphate assessment data available during Part 2 or Part 3 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in bone turnover markers including bone alkaline phosphatase (ALP), osteocalcin, and sclerostin was reported for combined Part 2 and 3. End of the study (EOS) was defined as the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in bone turnover markers for, tartrate-resistant acid phosphatase (TRAP) was reported for combined Part 2 and 3. End of the study was defined as the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in bone turnover markers including fibroblast growth factor 23 (FGF-23) was reported for combined Part 2 and 3. End of the study was defined as the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in bone turnover markers for parathyroid hormone was reported for combined Part 2 and 3. End of the study is the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in bone turnover markers for fetuin-A was reported for combined Part 2 and 3. End of the study is the completion if the participants has benefited from and desires to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in height for combined Part 2 and Part 3 for each drug at Week 8, 16 and end of study was reported. End of the study was defined as the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.

Change from baseline in weight for combined Part 2 and Part 3 for each drug at Week 8, 16 and end of study was reported. End of the study was defined as the completion if the participants benefited from and desired to continue dosing with lanthanum. Here, number of participants analyzed refers to the number of participants evaluable for this outcome at specified time point. Data was analyzed and presented as per the intervention received in this study related to this outcome and not analyzed based on each part of the study.

PP1 included participants who had taken at least 1 dose of investigational product and completed 8 weeks of calcium carbonate followed by 8 weeks of lanthanum carbonate and who had serum phosphate assessment data available during Part 2 to allow summarizing the percentage of participants achieving age-specific KDOQI target.