2.1 General Information

Administer Veltassa at least 3 hours before or 3 hours after other oral medications except those shown to not have a clinically important interaction [see Drug Interactions (7) and Clinical Pharmacology (12.3)].

Do not heat Veltassa (e.g., microwave) or add to heated foods or liquids. Do not take Veltassa in its dry form.

2.2 Recommended Dosing and Titration

The recommended starting dose of Veltassa is 8.4 grams patiromer once daily. Monitor serum potassium and adjust the dose of Veltassa based on the serum potassium level and the desired target range. The dose may be increased or decreased, as necessary, to reach the desired serum potassium concentration, up to a maximum dose of 25.2 grams once daily. The dose can be up-titrated based on serum potassium level at 1-week or longer intervals, in increments of 8.4 grams.

2.3 Preparation of Veltassa

Prepare each dose immediately prior to administration.

Measure 1/3 cup of water. Pour half of the water into a glass, then add Veltassa and stir. Add the remaining half of the water and stir thoroughly. The powder will not dissolve and the mixture will look cloudy. Add more water to the mixture as needed for desired consistency.

Drink the mixture immediately. If powder remains in the glass after drinking, add more water, stir and drink immediately. Repeat as needed to ensure the entire dose is administered.

Other beverages, or soft foods (e.g., apple sauce, yogurt, pudding) can be used instead of water to prepare the mixture by following the same steps as described above.

The potassium content of liquids or soft foods used to prepare the mixture should be considered as part of the dietary recommendations on potassium intake for each individual patient.

5.1 Worsening of Gastrointestinal Motility

Avoid use of Veltassa in patients with severe constipation, bowel obstruction or impaction, including abnormal post-operative bowel motility disorders, because Veltassa may be ineffective and may worsen gastrointestinal conditions.

Patients with a history of bowel obstruction or major gastrointestinal surgery, severe gastrointestinal disorders, or swallowing disorders were not included in the clinical studies.

5.2 Hypomagnesemia

Veltassa binds to magnesium in the colon, which can lead to hypomagnesemia. In clinical studies, hypomagnesemia was reported as an adverse reaction in 5.3% of patients treated with Veltassa [see Adverse Reactions (6.1)]. Monitor serum magnesium. Consider magnesium supplementation in patients who develop low serum magnesium levels on Veltassa.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of Veltassa cannot be directly compared to rates in the clinical trials of other drugs and may not reflect the rates observed in practice.

In the safety and efficacy clinical trials, 666 adult patients received at least one dose of Veltassa, including 219 exposed for at least 6 months and 149 exposed for at least one year.

Table 1 provides a summary of the most common adverse reactions (occurring in ≥ 2% of patients) in patients treated with Veltassa in these clinical trials. Most adverse reactions were mild to moderate. Constipation generally resolved during the course of treatment.

During the clinical studies, the most commonly reported adverse reactions leading to discontinuation of Veltassa were gastrointestinal adverse reactions (2.7%), including vomiting (0.8%), diarrhea (0.6%), constipation (0.5%) and flatulence (0.5%).

Mild to moderate hypersensitivity reactions were reported in 0.3% of patients treated with Veltassa in clinical trials. Reactions have included edema of the lips.

7.1 Clinically Important Interaction of Veltassa With Other Drugs

The in-vitro binding of the following drugs to patiromer was evaluated and potentially clinically significant binding was observed. Some drugs were subsequently tested in-vivo and significant reduction in systemic exposure was observed [see Dosage and Administration (2.1) and Clinical Pharmacology (12.3)].

7.2 No Observed Clinically Important Interaction of Veltassa with Other Drugs

The binding of the following drugs to patiromer was evaluated [see Section Pharmacokinetics (12.3)] and no clinically significant binding was observed. No separation of dosing is required for these drugs.

8.1 Pregnancy

8.2 Lactation

8.4 Pediatric Use

Safety and efficacy in pediatric patients have not been established.

8.5 Geriatric Use

Of the 666 patients treated with Veltassa in clinical studies, 59.8% were age 65 and over, and 19.8% were age 75 and over. No overall differences in effectiveness were observed between these patients and younger patients. Patients age 65 and older reported more gastrointestinal adverse reactions than younger patients.

8.6 Renal Impairment

Of the 666 patients treated with Veltassa in clinical studies, 93% had chronic kidney disease (CKD). No special dosing adjustments are needed for patients with renal impairment.

12.1 Mechanism of Action

Veltassa is a non-absorbed, cation exchange polymer that contains a calcium-sorbitol counterion.

Veltassa increases fecal potassium excretion through binding of potassium in the lumen of the gastrointestinal tract. Binding of potassium reduces the concentration of free potassium in the gastrointestinal lumen, resulting in a reduction of serum potassium levels.

12.2 Pharmacodynamics

In a Phase 1 study in healthy adult subjects (6 to 8 subjects per group), Veltassa (0 grams to 50.4 grams per day) administered three times a day for 8 days caused a dose-dependent increase in fecal potassium excretion. A corresponding dose-dependent decrease in urinary potassium excretion with no change in serum potassium were also observed. Compared to placebo, Veltassa doses of 25.2 and 50.4 grams per day significantly decreased mean daily urinary potassium excretion.

In a Phase 1, open-label, multiple-dose crossover study in 12 healthy subjects, 25.2 grams of patiromer per day was administered orally as a once daily, twice daily or thrice daily regimen for 6 days in a randomly assigned order. A significant increase in mean daily fecal potassium excretion and concomitant decrease in mean daily urinary potassium excretion were observed during the treatment periods for all three dosing regimens. The mean increase in fecal potassium excretion ranged from 1283 to 1550 mg/day, and the mean decrease in urinary potassium excretion ranged from 1438 to 1534 mg/day across the three dosing regimens. No significant differences were observed among the dosing regimens with respect to mean daily fecal potassium and urinary potassium excretion. This was true for the overall comparison among the three dosing regimens, as well as for the pairwise comparisons.

In an open-label, uncontrolled study, 25 patients with hyperkalemia (mean baseline serum potassium of 5.9 mEq/L) and chronic kidney disease were given a controlled potassium diet for 3 days, followed by 16.8 grams patiromer daily (as divided doses) for 2 days while the controlled diet was continued. A statistically significant reduction in serum potassium (-0.2 mEq/L) was observed at 7 hours after the first dose. Serum potassium levels continued to decline during the 48-hour treatment period (-0.8 mEq/L at 48 hours after the first dose). Potassium levels remained stable for 24 hours after the last dose, then rose during the 4-day observation period following discontinuation of Veltassa.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Patiromer was not genotoxic in the reverse mutation test (Ames assay), chromosome aberration or rat micronucleus assays.

Carcinogenicity studies have not been performed.

Patiromer did not impair the fertility in male or female rats at doses up to 10-fold the maximum recommended human dose (MRHD).

14.1 Two-Part, Randomized Withdrawal Study

The efficacy of Veltassa was demonstrated in a two-part, single-blind randomized withdrawal study that evaluated Veltassa in hyperkalemic patients with CKD on stable doses of at least one renin-angiotensin-aldosterone system inhibitor (i.e., angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, or aldosterone antagonist).

In Part A, 243 patients were treated with Veltassa for 4 weeks. Patients with a baseline serum potassium of 5.1 mEq/L to < 5.5 mEq/L received a starting Veltassa dose of 8.4 grams patiromer per day (as a divided dose) and patients with a baseline serum potassium of 5.5 mEq/L to < 6.5 mEq/L received a starting Veltassa dose of 16.8 grams patiromer per day (as a divided dose). The dose of Veltassa was titrated, as needed, based on the serum potassium level, assessed starting on Day 3 and then at weekly visits (Weeks 1, 2 and 3) to the end of the 4-week treatment period, with the aim of maintaining serum potassium in the target range (3.8 mEq/L to < 5.1 mEq/L).

The mean age of patients was 64 years, 58% of patients were men, and 98% were Caucasian. Approximately 97% of patients had hypertension, 57% had type 2 diabetes, and 42% had heart failure.

Results for the Part A primary endpoint, the change in serum potassium from Baseline to Week 4, are summarized in Table 4. Mean serum potassium over time for the intent-to-treat population is displayed in Figure 3. For the Part A secondary endpoint, 76% (95% CI: 70%, 81%) of patients had a serum potassium in the target range of 3.8 mEq/L to < 5.1 mEq/L at Week 4. The mean daily doses of Veltassa were 13 grams and 21 grams in patients with serum potassium of 5.1 to < 5.5 mEq/L and 5.5 to < 6.5 mEq/L, respectively.

Figure 3: Estimated Mean (95% CI) of Central Serum Potassium (mEq/L) Over Time

In Part B, 107 patients with a Part A baseline serum potassium of 5.5 mEq/L to < 6.5 mEq/L and whose serum potassium was in the target range (3.8 mEq/L to < 5.1 mEq/L) at Part A Week 4 and still receiving RAAS inhibitor medication were randomized to continue Veltassa or to receive placebo to evaluate the effect of withdrawing Veltassa on serum potassium. In patients randomized to Veltassa, the mean daily dose was 21 grams at the start of Part B and during Part B.

The Part B primary endpoint was the change in serum potassium from Part B baseline to the earliest visit at which the patient's serum potassium was first outside of the range of 3.8 to < 5.5 mEq/L, or to Part B Week 4 if the patient's serum potassium remained in the range. In Part B, serum potassium rose by 0.72 mEq/L in patients who were switched to placebo, versus no change in patients who remained on Veltassa. Results are summarized in Table 5.

More placebo patients (91%; 95% CI: 83%, 99%) developed a serum potassium ≥ 5.1 mEq/L at any time during Part B than Veltassa patients (43%; 95% CI: 30%, 56%), p < 0.001. More placebo patients (60%; 95% CI: 47%, 74%) developed a serum potassium ≥ 5.5 mEq/L at any time during Part B than Veltassa patients (15%; 95% CI: 6%, 24%), p < 0.001.

14.2 One-Year Study

The effect of treatment with Veltassa for up to 52 weeks was evaluated in an open-label study of 304 hyperkalemic patients with CKD and type 2 diabetes mellitus on RAAS inhibitor therapy. Figure 4 shows that the treatment effect on serum potassium was maintained during continued therapy. In patients with a baseline serum potassium of > 5.0 to 5.5 mEq/L who received an initial dose of 8.4 grams patiromer per day (as a divided dose), the mean daily dose was 14 grams; in those with a baseline serum potassium of > 5.5 to < 6.0 mEq/L who received an initial dose of 16.8 grams patiromer per day (as a divided dose), the mean daily dose was 20 grams during the entire study.

Figure 4: Mean (95% CI) Serum Potassium over Time

16.1 How Supplied

Veltassa is supplied as a powder for oral suspension formulated with xanthan gum. Veltassa is packaged in single-use packets containing 8.4 grams, 16.8 grams or 25.2 grams patiromer as follows:

16.2 Stability and Storage

Veltassa should be stored in the refrigerator at 2°C to 8°C (36°F to 46°F).

If stored at room temperature (25°C ± 2°C [77°F ± 4°F]), Veltassa must be used within 3 months of being taken out of the refrigerator. For either storage condition, do not use Veltassa after the expiration date printed on the packet.

Avoid exposure to excessive heat above 40°C (104°F).

Drug Interactions

Advise patients who are taking other oral medication that separation of dosing of Veltassa by at least 3 hours (before or after) may be needed except those shown to not have a clinically important interaction in table 3 above. [see Drug Interactions (7)].

Dosing Recommendations

Inform patients to take Veltassa as directed and adhere to their prescribed diets.

Inform patients that Veltassa should not be heated (e.g., microwaved) or added to heated foods or liquids and should not be taken in its dry form.